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دسترسی آزاد مقاله
1 - Investigating the Performance of Coated Carbide Insert in Hard Steel Helical Milling
Navid Molla Ramezani Behnam Davoodi Mojtaba Rezaee HajidehHelical milling is an alternative hole-making machining process which presents several advantages when compared to conventional drilling. In the helical milling process, the tool proceeds a helical path while rotates around its own axis. Due to its flexible kinematics, چکیده کاملHelical milling is an alternative hole-making machining process which presents several advantages when compared to conventional drilling. In the helical milling process, the tool proceeds a helical path while rotates around its own axis. Due to its flexible kinematics, low cutting forces, tool wear, and improved borehole quality may be achieved. In this study, a new helical milling process to create holes in hardened steel with a hardness of HRC 52 was used. Carbide inserts with PVD TiN coating were applied. Input parameters including cutting speed and feed rate were considered in 4 and 2 levels, respectively. In order to increase the reliability of the results, experiments were repeated 4 times and the total of 32 tests were performed. Other cutting parameters, such as axial and radial depth of cut were constant. Machining process was performed in dry state and without any lubricant. Output characteristics were tool wear, surface roughness, cutting force, machining time and material removal rate. Tool wear, surface roughness and forces, were measured by tool maker microscopy, roughness tester and dynamometer, respectively. The results showed that increasing the cutting speed on this type of hardened steel, decreases the surface roughness, machining forces and machining time. However, increasing the cutting speed and the feed rate enhances the tool wear and material removal rate considerably. Cutting speed and Feed rate of 50 m/min and 0.05 mm/tooth, offered the best mechanical properties of the Machining. پرونده مقاله -
دسترسی آزاد مقاله
2 - Expert System Approach for Optimization of Design and Manufacturing Process for Rotary Ultrasonic Machining
Morteza Sadegh AmalnikAn expert system for evaluating rotary ultrasonic machining, in concurrent engineering environment and based on object oriented techniques, is developed. The design specification is obtained through a feature based approach. Different classes of design features are inte چکیده کاملAn expert system for evaluating rotary ultrasonic machining, in concurrent engineering environment and based on object oriented techniques, is developed. The design specification is obtained through a feature based approach. Different classes of design features are interactively acquired. The attributes of different hard and brittle materials like glass, composite, stone and ceramic as work piece materials are stored in database. The system is also linked with tool material and machine databases. For each design feature, information is needed in manufacturing, such as machining cycle time, and cost, penetration rate, and efficiency are estimated by the expert system. Software system such as expert system based on object oriented technique is used to develop the expert system. The system links with a feature based CAD system in order to extract design data. The expert system provides useful information such as machining cycle time and cost, penetration rate, efficiency of machining of the selected design feature for product designers and advises of manufacturing engineers to select optimum machining parameters. In order to test the validity of the system, results of expert system is compared with the results of experimental rotary ultrasonic machining. پرونده مقاله -
دسترسی آزاد مقاله
3 - Effect of the Micro Wire-EDM Process Parameters on the Recast Layer in the Molybdenum Micromachining
Mohammad Tahmasebipour Y. Tahmasebipour A. Shabani M. Boujari AliabadiThe Micro wire electrical discharge machining (Micro wire-EDM) process is a modern machining process with various applications in manufacturing micro-parts. The recast layer remaining on the machined surfaces is an inevitable complication of this process. This layer can چکیده کاملThe Micro wire electrical discharge machining (Micro wire-EDM) process is a modern machining process with various applications in manufacturing micro-parts. The recast layer remaining on the machined surfaces is an inevitable complication of this process. This layer can subsequently affect the machined parts performance. To optimize the recast layer in the micro wire-EDM of the molybdenum microparts, effect of the process parameters on the distribution amplitude of the recast layer was investigated using the Taguchi method. The obtained results showed that the optimal levels of the micro wire-EDM process parameters for achieving the optimal distribution amplitude of the recast layer are as follows: spark pulse-on time of 0.2 μs, cutting speed of 7 mm/min, process voltage of 17 V, and wire tension of 0.45 kg. Also the importance order of the effect of the process parameters on the distribution amplitude of recast layer is as follows: spark pulse-on time, process voltage, cutting speed, and wire tension. پرونده مقاله -
دسترسی آزاد مقاله
4 - Effect of AFM Cantilever Geometry on the DPL Nanomachining Process
A. R. Norouzi M. TahmasebipourWith the development of micro and nanotechnology, machining methods at micro and nanoscale have now become interesting research topics. One of the recently-proposed methods for sub-micron machining, especially nanomachining, is dynamic plowing lithography (DPL) method. چکیده کاملWith the development of micro and nanotechnology, machining methods at micro and nanoscale have now become interesting research topics. One of the recently-proposed methods for sub-micron machining, especially nanomachining, is dynamic plowing lithography (DPL) method. In this method an oscillating tip is used for machining soft materials such as polymers. The geometry of the oscillating beam and its vibrational properties are the most important parameters in this nanomachining process. In this study, effects of the AFM beam geometry on its stiffness coefficient, resonant frequency, beam stability, and the maximum stress created in the beam structure were investigated for 12 different general shapes using the finite element method. The obtained results indicate that circular and square membranes are the most favourable AFM cantilever geometries because these structures provide higher machining force and speed; while for noisy conditions and environments, straight and V-shaped beams are recommended (because of their higher stability factor) for the DPL nanomachining process. پرونده مقاله -
دسترسی آزاد مقاله
5 - Precision Force Measurement and Control in Micro Ultrasonic Machining
Hamid Zarepour FirouzabadiMicro ultrasonic machining (Micro-USM) is a process with a great capability to generate micro features in hard and brittle materials. Despite some developments in micro-USM process, issues such as precision measurement and control of the machining force, which is crucia چکیده کاملMicro ultrasonic machining (Micro-USM) is a process with a great capability to generate micro features in hard and brittle materials. Despite some developments in micro-USM process, issues such as precision measurement and control of the machining force, which is crucial for stable machining conditions, need further investigations. In this paper, the precision measurement and control of the machining force is studied using a newly-developed force measurement configuration. The results of the force measurement for different levels of static force, abrasive particle size and amplitude of vibration demonstrated that the variation of measured machining force increases at higher static forces. Furthermore, a better control over the static load was acquired when feeding the abrasive slurry with particle size of 0.37 mm as compared to 1 mm and 3 mm particles leading to more stable machining conditions in micro-USM process. Finally, applying lower levels of vibration amplitude to the workpiece resulted in more stable machining conditions and lower static load errors. پرونده مقاله -
دسترسی آزاد مقاله
6 - Thermal Loads and Surface Quality Evaluation in Machining of Hardened Die Steel under Dry and Cryogenic Machining
Farshid Jafarian Emad MohseniAISI H13 die steel is widely used in different industries because of its especial properties. During the machining of hard materials, some of the mechanical properties of the material are changed due to the generation of intensive thermo-mechanical loads and plastic def چکیده کاملAISI H13 die steel is widely used in different industries because of its especial properties. During the machining of hard materials, some of the mechanical properties of the material are changed due to the generation of intensive thermo-mechanical loads and plastic deformation into the workpiece. Controlling these intensive changes in machined surfaces is an important task and significantly affects the performance of the machined part. In addition, surface roughness is one of the aspects of surface texture and affects the fatigue life of the material. Since machining of hard materials is a difficult procedure and it is confronted with several limitations, new methods in machining processes are essential to be developed. One of these methods is using cryogenic coolant where the machining temperature may be considerably reduced by spraying liquid nitrogen on the cutting region. Based on this, at the present study, the variation of thermal loads and surface roughness at different machining parameters were evaluated under dry and cryogenic conditions. To do this, a thermal infrared camera and liquid nitrogen delivery system was used during the machining of hardened AISI H13 steel. Compared with dry condition, the effectiveness of the cryogenic coolant on surface roughness and thermal loads were analysed and discussed at different cutting speed, feed rate, and depth of cut. Finally, it was found that, applying cryogenic coolant in machining of AISI H13 die steel can be very effective to enhance performance and quality of the machined component in terms of surface roughness and thermal loads. پرونده مقاله -
دسترسی آزاد مقاله
7 - Design and Manufacturing Optimization of Abrasive Water Jet Machining using Expert System
Morteza sadegh amalnikThis paper addresses the concept of the expert system for abrasive waterjet machining. For optimization of abrasive waterjet machining, computer based concurrent engineering environment is used. The design specification is acquired through a feature based approach. The چکیده کاملThis paper addresses the concept of the expert system for abrasive waterjet machining. For optimization of abrasive waterjet machining, computer based concurrent engineering environment is used. The design specification is acquired through a feature based approach. The expert system links with feature base library. The expert system links with material database which holds attributes of more than 20 type of materials. It also links with abrasive data base which hold attributes of 8 types of abrasive, and also 4 type and size of machine. expert system also links with machine database which hold machine parameters. For each design feature, the expert system provides information needed for optimization of design and manufacturing. The expert system can be used as an advisory system for optimization of design and manufacturing. It can be used as a teaching program for new abrasive waterjet machining operators. For each design feature, the expert system provides information such as machining cycle time and cost and cutting rate. By changing machine parameters, we can optimize machining cycle time and cost and cutting rate. Comparison results of the expert system and experimental CNC Abrasive waterjet results for different design feature shows that machining time and cost of expert system is 10% less than experimental. پرونده مقاله -
دسترسی آزاد مقاله
8 - Micro Wire Electrical Discharge Machining of MEMS Structures with Optimized Dimensional Deviation
Mohammad Tahmasebipour Younes Tahmasebipour Ali VafaieMetal-based microelectromechanical systems are widely used in applications such as micro-energy harvesters, micro-heat exchangers and micro-electromagnetic that require high strength and flexibility. In the fabrication of such systems, micro wire electrical discharge ma چکیده کاملMetal-based microelectromechanical systems are widely used in applications such as micro-energy harvesters, micro-heat exchangers and micro-electromagnetic that require high strength and flexibility. In the fabrication of such systems, micro wire electrical discharge machining (MicroWEDM) is majorly used. This paper studies the effect of the MicroWEDM process parameters on the dimensional deviation of machined MEMS structures including microcantilevers and micro-beams using the Taguchi method. Using optimal levels of the parameters including pulse duration (0.8 µs), cutting speed (8.4 mm/min), voltage (17 V) and wire tension (0.5 kg), the dimensional deviation is reduced about 8.65 times compared with the average of experiments results. The order of effect importance of the process parameters on the dimensional deviation of microstructures obtained by the ANOVA analysis of S/N ratios is as follows: pulse duration, wire tension, process voltage and cutting speed. Dimensional deviation of the micro-features was reduced to 1 μm using the optimal levels of the process parameters. پرونده مقاله -
دسترسی آزاد مقاله
9 - Experimental Study of the Effect of Variable Pitch in Indexable Cutting Tool on AISI4140 Steel Surface Finish in Milling
Behrouz Mahdikhani Mehrdad JavadiChatter is one of the most limitations that cause undesirable effect on improving productivity and part quality. In this paper, an experimental method has been used for analysing the effect of changing pitch in the indexable cutting tool in milling. For this purpose, th چکیده کاملChatter is one of the most limitations that cause undesirable effect on improving productivity and part quality. In this paper, an experimental method has been used for analysing the effect of changing pitch in the indexable cutting tool in milling. For this purpose, the cutting forces of machining in three different directions were investigated and a comparison was made between tools with equal and unequal pitches. Milling of AISI 4140 has been performed with two different depths of cut (0.5&1mm) and the machining surface finish were examined. Furthermore, by using accelerometer sensors, the machining vibrations and machining forces by using dynamometer were measured. According to the findings, as well as the reduction of vibrations of machining about 50 %, machining forces reduction between 15% and 30% and surface finish improvement more than 200%were observed. In this regard, utilizing tools with different pitches leads to improvement in machining efficiency, reducing energy consumption, manufacture of high quality parts and it will ultimately reduce costs. پرونده مقاله -
دسترسی آزاد مقاله
10 - The Effect of Process Parameters and Tool Geometrical Parameters on the Tool Peak Temperature in Machining Process
Maziar Mahdipour Jalilian Amir Ghiasvand Hasan KheradmandanIn the present study, the effects of process and geometrical parameters on the maximum temperature of tool have been investigated. Simulation of mild steel machining process in different cutting depths, speed of rotation (SOR), feeding rates, and different rake angles w چکیده کاملIn the present study, the effects of process and geometrical parameters on the maximum temperature of tool have been investigated. Simulation of mild steel machining process in different cutting depths, speed of rotation (SOR), feeding rates, and different rake angles was performed. To verify the simulation, numerical results were compared with experimental results. Based on the results, it was found that by increasing the speed of rotation at a constant cutting depth and a constant feed rate, the maximum temperature of the process experiences a significant increase. By increasing the depth of the cut, the geometric location of the workpiece maximum temperature was transmitted to the edge of the tool and surface changes occurred, which it was accompanied with increment in the depth of the cut. The tool with the rake angle of -10° and the depth of cutting of 2 mm had the highest recorded temperature due to the lack of sufficient space for removing chips from the work surface. پرونده مقاله -
دسترسی آزاد مقاله
11 - Evaluation of Fatigue Behavior and Surface Characteristics of Novel Machining Process: Rotary Chemical Machining (RCM)
Pooya Bahrami Ali Khoshanjam Abdolhamid AziziIn this study, Rotational Chemical Machining (RCM) as a novel machining process is introduced. The properties such as surface roughness and residual stress as well as fatigue strength of the RCM process are evaluated, discussed and compared to the conventional turning p چکیده کاملIn this study, Rotational Chemical Machining (RCM) as a novel machining process is introduced. The properties such as surface roughness and residual stress as well as fatigue strength of the RCM process are evaluated, discussed and compared to the conventional turning process. In this sense, Scanning Electron Microscope (SEM) and Atomic Force Microscope (AFM) were utilized. The results show the superiority of the RCM method over the conventional method and eliminate limits of process such as low surface quality and improve fatigue strength. The Amplitude Distribution Curve has a balanced Gaussian shape in RCM indicating the balanced distribution of peaks and valleys on machined surface. Due to the absence of machining force in the RCM process, in comparison to the turning process, maximum residual stress is significantly decreased from 363Mpa to 71Mpa; surface roughness reduced from 3.1µm to 1.5 µm as well as the fatigue strength improved 20% approximately. پرونده مقاله -
دسترسی آزاد مقاله
12 - Investigation of the TiO2/SiC/SiO2 Coating Effect On the Wear Rate of Needle Graphite Electrode by using Electrical Discharge Machining
Hossein Alian Moghadam majid jabbari Saeed Daneshmand Saeid Rasouli Jazi Arezoo KhosraviNeedle graphite electrodes are one of the main parts used in electric arc furnaces. These electrodes have a significant impact on melt quality and product quality, and their consumption is one of the most important parameters of steel production cost in EAF furnaces. Th چکیده کاملNeedle graphite electrodes are one of the main parts used in electric arc furnaces. These electrodes have a significant impact on melt quality and product quality, and their consumption is one of the most important parameters of steel production cost in EAF furnaces. Therefore, reducing the consumption of needle graphite electrodes in these furnaces is very important. The main reasons for continuous use of needle graphite electrodes in arc furnaces are oxidation of the sidewalls and sublimation of their tips, and many solutions have been proposed to reduce them. In the present study, the effect of coating consisting of TiO2/SiC/SiO2 elements on the wear rate of the needle graphite electrode in the sublimation state is investigated using EDM (Electrical Discharge Machining- Spark device). For this purpose, the effect of voltage, current, pulse on time and pulse off time on the electrode wear rate are investigated and in this regard, Taguchi design method has been used to reduce the number of experiments. Based on the test results, TiO2/SiC/SiO2 coating reduces the wear rate of the needle graphite electrode due to sublimation. پرونده مقاله -
دسترسی آزاد مقاله
13 - Prediction of Material Removal Rate in Ductile–Mode Micro Ultrasonic Machining
Hamid ZarepourThis paper presents a model to predict Material Removal Rate (MRR) in Micro Ultrasonic Machining (micro-USM). The proposed model is developed based on the ductile-mode of material removal in micro-USM process. The correlation between ductile material removal rate and pr چکیده کاملThis paper presents a model to predict Material Removal Rate (MRR) in Micro Ultrasonic Machining (micro-USM). The proposed model is developed based on the ductile-mode of material removal in micro-USM process. The correlation between ductile material removal rate and process parameters including frequency and amplitude of the ultrasonic vibration, particle size, and slurry concentration is presented. The proposed predictive model is verified by performing micromachining experiments using two types of workpiece materials including silicon and quartz at various process parameters levels. The results show that the MRR increases with a rise in vibration amplitude for both silicon and quartz materials. The experimental MRR values follow a trend similar to that of predicted MRR values. However, the predicted MRR values are higher than the measured MRR values for both silicon and quartz materials. The measured MRR values for ductile removal mode were found to have a considerable increase at vibration amplitudes of 2 mm and 2.4 mm for silicon and quartz, respectively, which is in favour of increasing the accuracy of the model prediction. پرونده مقاله -
دسترسی آزاد مقاله
14 - Micro Electropolishing of the MEMS Metallic Structures Fabricated by the Micro WEDM Process
Mohammad Tahmasebipour Younes Tahmasebipour Mahya Boujari Aliabadi Shadi EbrahimiIn this study, the micro electro-polishing method was employed to improve the surface quality of microbeams machined by the micro WEDM method and to remove the recast layer. This approach changes the dimensions of the microbeams, as a result of the electrochemical corro چکیده کاملIn this study, the micro electro-polishing method was employed to improve the surface quality of microbeams machined by the micro WEDM method and to remove the recast layer. This approach changes the dimensions of the microbeams, as a result of the electrochemical corrosion, in addition to the elimination of the recast layer. To diminish the impact of this process on the dimensional deviation of the fabricated microbeams, the influence of the micro electro-polishing process parameters such as voltage, duration, cathode diameter, and electrolyte composition on the dimensional deviation of microbeams was studied using the Taguchi method. The optimum values of process parameters were determined by the S/N ratios analysis, and the order of parameters importance was determined through analysis of variance of the S/N ratios. It was found that the optimal levels of the process parameters are voltage of 2 V, process duration of 20 s, cathode diameter of 50 mm, and electrolyte composition of 25-5-40 ml (sulfuric-phosphoric-water) within the range of experiments. By using the optimum values of the parameters, the dimensional deviations were found to be 5.23 times lower compared to the average of the results. The importance of process parameters was found to follow this order: electropolishing duration, electrolyte composition, cathode diameter, and process voltage. پرونده مقاله -
دسترسی آزاد مقاله
15 - مطالعه تجربی تاثیر نانو سیال SiO2 بر روی نیروی ماشینکاری در فرایند تراش کاری فولاد AISI 4340
محسن خواجه زاده قربانعلی مومندر این مقاله تاثیر نانو سیال دی اکسید سیلیکون (SiO2) با سیال پایه آب بر روی نیروی ماشین کاری قطعه کار در فرآیند تراش کاری فولاد ابزار عملیات حرارتی شده (AISI 4340) مورد مطالعه قرار گرفته و نتایج حاصل با حالت خشک مقایسه شده است. نتایج به دست آمده نشان می دهد افزودن نانو چکیده کاملدر این مقاله تاثیر نانو سیال دی اکسید سیلیکون (SiO2) با سیال پایه آب بر روی نیروی ماشین کاری قطعه کار در فرآیند تراش کاری فولاد ابزار عملیات حرارتی شده (AISI 4340) مورد مطالعه قرار گرفته و نتایج حاصل با حالت خشک مقایسه شده است. نتایج به دست آمده نشان می دهد افزودن نانو ذرات دی اکسید سیلیکون به مقدار 1% حجمی به آب موجب کاهش قابل ملاحضه مقدار نیروی ماشین کاری نسبت به حالت خشک می شود. بر اساس نتایج حاصل نانوسیال دی اکسید سیلیکون (SiO2) نیروی ماشین کاری را 24% نسبت به حالت خشک کاهش می دهد و در هنگام استفاده از نانوسیال مذکور در محدوده آزمایش های به عمل آمده کمترین نیروی ماشینکاری در سرعت پیشروی0.1 میلی متر بر دور و سرعت برشی 400 متر بر دقیقه حاصل شد. پرونده مقاله -
دسترسی آزاد مقاله
16 - Machine scheduling for multitask machining
Saleh Yavari Ahmed Azab Mohammed Fazle Baki Mikel Alcelay Justin BrittMultitasking is an important part of today’s manufacturing plants. Multitask machine tools are capable of processing multiple operations at the same time by applying a different set of part and tool holding devices. Mill-turns are multitask machines with the abili چکیده کاملMultitasking is an important part of today’s manufacturing plants. Multitask machine tools are capable of processing multiple operations at the same time by applying a different set of part and tool holding devices. Mill-turns are multitask machines with the ability to perform a variety of operations with considerable accuracy and agility. One critical factor in simultaneous machining is to create a schedule for different operations to be completed in minimum make-span. A Mixed Integer Linear Programming (MILP) model is developed to address the machine scheduling problem. The adopted assumptions are more realistic when compared with the previous models. The model allows for processing multiple operations simultaneously on a single part; parts are being processed on the same setup and multiple turrets can process a single operation of a single job simultaneously performing multiple depths of cut. A Simulated Annealing algorithm with a novel initial solution and assignment approach is developed to solve large instances of the problem. پرونده مقاله -
دسترسی آزاد مقاله
17 - Multi-objective Optimization of Turning of Titanium Alloy Under Minimum Quantity Lubrication
Satish Chinchanikar Jitendra Katiyar Omkar ManavIn the present study, the machining performance of titanium grade-1 alloy is evaluated in terms of resultant cutting force, machined surface roughness, and material removal rate (MRR) through a multi-objective optimization approach. Turning experiments were performed wi چکیده کاملIn the present study, the machining performance of titanium grade-1 alloy is evaluated in terms of resultant cutting force, machined surface roughness, and material removal rate (MRR) through a multi-objective optimization approach. Turning experiments were performed with CVD-coated TiCN-Al2O3 carbide inserts using vegetable oil-based nanofluid under minimum quantity lubrication. The nanofluid was prepared using coconut oil as a base fluid mixed with boron nitride (hBN) nanoparticles. Experiments were performed by varying the cutting speed, feed, depth of cut, and nanoparticles concentration in a base fluid. The Desirability Function Approach (DFA), a Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), Grey Relational Analysis (GRA), and Non-dominated Sorting Genetic Algorithm (NSGA-II) are used to optimize the machining performance. The optimized solutions from different optimization techniques are observed in better agreement. The results show optimum performance at the higher cutting speed, higher depth of cut, lower feed, and lower concentration of nanoparticles. Lowest values for resultant force and surface roughness of 387 N and 0.47 µm, respectively, and maximum MRR of 9375 mm3/min could be obtained using the cutting speed, feed, depth of cut, and nanoparticles concentration of 125 m/min, 0.1 mm/rev, 0.75 mm, and 0.3%, respectively. However, little compromising the surface roughness to a higher value of 0.83 µm with almost the same resultant force, the higher MRR of 15000 mm3/min could be obtained using higher cutting parameters. It has been observed that the resultant force and surface roughness are significantly affected by the depth of cut and feed, respectively. However, the concentration of nanoparticles has been observed to have a lower prominent effect on the surface roughness and resultant force. پرونده مقاله -
دسترسی آزاد مقاله
18 - Using design of experiments approach and simulated annealing algorithm for modeling and Optimization of EDM process parameters
Masoud Azadi Moghaddam Farhad Kolahan Meysam BeytolamaniThe main objectives of this research are, therefore, to assess the effects of process parameters and to determine their optimal levels machining of Inconel 718 super alloy. gap voltage, current, time of machining and duty factor are tuning parameters considered to be st چکیده کاملThe main objectives of this research are, therefore, to assess the effects of process parameters and to determine their optimal levels machining of Inconel 718 super alloy. gap voltage, current, time of machining and duty factor are tuning parameters considered to be study as process input parameters. Furthermore, two important process output characteristic, have been evaluated in this research are material removal rate (MRR) and surface roughness (SR). Determination of a combination of process parameters to minimize SR and maximize MRR is the objective of this study. In order to gather required experimental data, design of experiments (DOE) approach, has been used. Then, statistical analyses and validation experiments have been carried out to select the best and the most fitted regression models. In the last section of this research, simulated annealing (SA) algorithm has been employed for optimization of the EDM process performance characteristics. A set of verification tests is also performed to confirm the accuracy of the proposed optimization procedure in determining the optimal levels of machining parameters. The results indicate that the proposed modeling technique and SA algorithm are quite efficient in modeling and optimization of EDM process parameters. پرونده مقاله -
دسترسی آزاد مقاله
19 - Preparing and Investigation a New Nanofluid for Employing in Machining Process: Synthesis and Characterization of Graphene Oxide Nanoparticles
Ramin RanjbarzadehThe quality of machined workpieces, particularly precious metals, is the main goal of every machining process. A suitable cutting fluid can substantially affect the machining outcome. The present study is novel in that it uses nanofluids in the machining process to miti چکیده کاملThe quality of machined workpieces, particularly precious metals, is the main goal of every machining process. A suitable cutting fluid can substantially affect the machining outcome. The present study is novel in that it uses nanofluids in the machining process to mitigate the adverse effects of high temperatures and fraction. Graphene oxide (GO) nanoparticles were synthesized using the modified Hummers method. FTIR, FESEM and XRD tests were used for GO characterization and also for atomic, surface and chemical analyses. The studied workpiece was a bronze shaft, ⌀20 mm. Different nanofluid solutions (0.25 and 0.5 vol%) were applied to reduce the machining loads and increase the workpiece flatness. The results were then compared with those from a base water-oil (90-10 vol%) cutting fluid (Behran, Iran). The NP characterization confirmed the satisfactory quality of the particles. It also showed that the effect of NP on the machining forces is substantial. Accordingly, the largest reduction in the mean machining force was achieved when using the 0.5% nanofluid solution (28.34% less than the base fluid). The surface roughness of the bronze shaft was lower when using the 0.5% nanofluid (0.57 μm) instead of the base fluid (0.668 μm). Finally, it can be concluded that this nanofluid can be an alternative to the base fluids in the machining process. پرونده مقاله -
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20 - Investigation of Parameters Affecting Surface Integrity and Material Removal during Electrical Discharge Machining of HARDOX-400 Steel
Hesam Motevasseli Ahmad Afsari Ali KhosravifardHardox-400 with an extra-high yield strength of ~1000 MPa and excellent abrasion resistance is a good candidate for several industrial applications including automotive parts, working tools, barges, loaders, etc. Due to high dimensional precision and to avoid mechanical چکیده کاملHardox-400 with an extra-high yield strength of ~1000 MPa and excellent abrasion resistance is a good candidate for several industrial applications including automotive parts, working tools, barges, loaders, etc. Due to high dimensional precision and to avoid mechanical abrasion of the work-piece, electrical discharge machining (EDM) is a proper machining technique for such steel. The influences of important process parameters, i.e. discharge current and spark pulse cycle on the electrode wear, material removal, surface roughness, and integrity of the machined material is investigated. It was observed in this work that as the discharge current increased, the electrode wear also increased but this occurred with a gradually decreasing rate. On the other hand, increasing the ratio of pulse-on to pulse-off time decreased material removal. Furthermore, it was observed that increasing both the discharge current and the pulse-on time led to a thicker solidified so-called white layer which is more susceptible to cracking and thus is detrimental to the material integrity. پرونده مقاله -
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21 - An Investigation on the Effect of Acidithiobacillus Ferrooxidans Bacteria on Biomachining of Titanium Alloy and Copper
Mehrdad Ghani Hamid Soleimanimehr Elham Shirani BidabadiRecent advances in technology have increased the necessity of using components with Micro and Nano dimensions. In recent years, the use of bacteria as a renewable tool has hopeful applications in producing different work-pieces. In this study, the effect of Acidithiobac چکیده کاملRecent advances in technology have increased the necessity of using components with Micro and Nano dimensions. In recent years, the use of bacteria as a renewable tool has hopeful applications in producing different work-pieces. In this study, the effect of Acidithiobacillus Ferrooxidans (A.F) on Vt20 (Titanium alloy) and Cu were investigated. The results illustrated that in the medium of the Aerobic bacteria A.F, the layer of TiO2 on the surface of Vt20 is formed and this oxide layer impedes Vt20 corrosion. Furthermore, it was observed that Cu in a medium of A.F is corroded in the same condition. According to these results, biomachining by A.F is considered as a new approach that is used for Micro-Bio grooving on Cu, but this method has different effects on Vt20. So that due to improving the hardness of Vt20 and high resistance of this alloy against abrasion, this method can be used for coating space traveling equipment, automotive industries and home appliance. On the other hand the effect of pH and temperature on Vt20 were studied and it was observed that the increase in pH and temperature improve the resistance of Vt20 against the surface corrosion. پرونده مقاله -
دسترسی آزاد مقاله
22 - Imperialist Competitive Algorithm (ICA) Approach for Optimization of the Surface Grinding Process
Ahmad Afsari Mohammad Ramezani Shahin Heidari Jafar KarimiThe imperialist Competitive Algorithm (ICA) is one of the recent meta-heuristic algorithms proposed to solve optimization problems. The Imperialist Competitive Algorithm is based on a socio-politically inspired optimization strategy. This paper presents an Imperialist C چکیده کاملThe imperialist Competitive Algorithm (ICA) is one of the recent meta-heuristic algorithms proposed to solve optimization problems. The Imperialist Competitive Algorithm is based on a socio-politically inspired optimization strategy. This paper presents an Imperialist Competitive Algorithm (ICA) to optimize the performance of a surface grinding operation. Moreover, the multi-objective optimization of a surface grinding process is suggested by using an evolutionary algorithm. Factors like depth of dressing, lead of dressing, workpiece speed and wheel speed are considered to minimize the production cost, surface roughness and to maximize the production rate. The suggested approach presents two constraints handling techniques: constraints handling strategy of ICA and penalty function method. The effectiveness of this algorithm for grinding operation is investigated by comparing the results to other algorithms available in the literature. Results show that the proposed algorithm in this work gives a better performance in a shorter time for the optimization of machining parameters in comparison to other works. پرونده مقاله -
دسترسی آزاد مقاله
23 - Experimental Study of Germanium Dry Machining with Various Rake Angles and Different Feed Rates of Tool
Mohammad Reza Safavipour Masoud FarahnakianToday, germanium single-crystals are used as an infrared and semiconductor material in the manufacturing of infrared optical lenses and windows (thermal vision), gamma-ray detectors, and substrates for optoelectronic and electronic applications. Given that germanium is چکیده کاملToday, germanium single-crystals are used as an infrared and semiconductor material in the manufacturing of infrared optical lenses and windows (thermal vision), gamma-ray detectors, and substrates for optoelectronic and electronic applications. Given that germanium is an optically brittle material with high brittleness and brittle failure that mainly affects the surface integrity of the machined part on this material; In this experimental study, by changing the rake angle and feed rate of the cutting tool, experiments were performed to determine the appropriate rake angles and suitable feed rates and their effects on the surface roughness and texture of the relevant surface for germanium turning in the dry state. The results show that with increasing the rake angle and decreasing the feed rate of the cutting tool, the surface roughness decreases, which reduces the surface damage to a considerable extent. The purpose of this experimental study is to create a surface with the desired quality in the machining process of the germanium optical part using ductile mode machining and to change the parameters of this process to control the configuration and dimensions of microstructures, micro-cracks, micro craters, and Surface pits. پرونده مقاله -
دسترسی آزاد مقاله
24 - Experimental Study of the Effect of Different Spindle Speeds and Feed Rates in Dry Machining on a Brittle Material
Mohammad Reza Safavipour Masoud FarahnakianMaterial removal modes in brittle material machining are divided into two categories: ductile modes and brittle modes. Many believe that there is a clear difference between energy costs in these two cases. Spindle speed (SS) and feed rate are the effective parameters in چکیده کاملMaterial removal modes in brittle material machining are divided into two categories: ductile modes and brittle modes. Many believe that there is a clear difference between energy costs in these two cases. Spindle speed (SS) and feed rate are the effective parameters in the material machining process. It is tried to conduct experimental studies on the effect of low spindle speeds and high feed rates on the turning of brittle material in this paper. Also, the tool geometry is an important factor in turning brittle materials; so the rake angle of the turning tool was changed for dry machining of a single-crystal workpiece. The results show that the surface roughness decreases by increasing the spindle speed and decreasing the feed rate, which reduces the surface damage significantly. The purpose of this experimental study is to investigate the effect of rotational speed and feed rate on surface roughness and surface texture in the lathe process of the workpiece using the ductile mode of machining and changes in the parameters of this process to control the configuration and dimensions of microstructures (micro craters, Surface pits, and micro-cracks). پرونده مقاله -
دسترسی آزاد مقاله
25 - Investigation of the Impact of the Alumina Powder Presence in Dielectric on Electrical Discharge Machining Parameters of A413 Aluminum Workpiece using Taguchi's Experiment Design, Signal-to-noise Analysis, and Total Normalized Quality Loss
Mojtaba Shahbazi Dastjerdi Ali Mokhtarian Mojtaba RahimiThis study aimed to scrutinize the impact of the electrical discharge machining (EDM) parameters of A413 alloy for two cases of dielectric, one with alumina powder and one without, using Taguchi's experiment design method. The completed studies regarding the EDM of the چکیده کاملThis study aimed to scrutinize the impact of the electrical discharge machining (EDM) parameters of A413 alloy for two cases of dielectric, one with alumina powder and one without, using Taguchi's experiment design method. The completed studies regarding the EDM of the metal-base composites reveal that insufficient research work has been carried out on this composite material. In this research, by using Taguchi's experiment design and through the simultaneous analysis of Total Normalized Quality Loss (TNQL) and Signal-to-Noise ratio (S/N) of the outputs, the impacts of the current intensity, voltage, pulse on-time, and pulse off-time on the material removal rate (MRR), surface roughness (SR), and tool wear rate (TWR) were investigated. The results showed that the use of 3g/L of alumina powder in kerosene dielectric averagely led to a 6.47%, 9.14%, and 19.40% reduction in MRR, SR, and TWR, respectively. Also, the results acquired using TNQL and S/N analyses demonstrated that the optimum experiment was composed of the third level of voltage (A3), the first level of current (B1), the first level of pulse on-time (C1), and the third level of pulse-off time (D3). It was concluded that the current intensity had the greatest impact on the MRR and SR. However, the pulse-on time had the greatest influence on the TWR. It was also observed that the MRR declined by adding 3g/L aluminum oxide powder in the kerosene dielectric which in turn caused a reduction in the SR and the TWR compared to the case of the kerosene dielectric without powder. پرونده مقاله -
دسترسی آزاد مقاله
26 - Machining Operation Parameters in Drilling Process; Variation of Thrust Forces in Epoxy Based Nanocomposites
Hamzeh Shahrajabian Masoud Farahnakian Mehdi MoghriDuring the past decade, polymer nanocomposites have emerged relatively as a new and rapidly developing class of composite materials and attracted considerable investment in research and development worldwide.Direct machining of polymers can be an option for personalized چکیده کاملDuring the past decade, polymer nanocomposites have emerged relatively as a new and rapidly developing class of composite materials and attracted considerable investment in research and development worldwide.Direct machining of polymers can be an option for personalized products and for manufacturing product samples. To obtain high quality products and reduce machining costs, it is very important to understand the machining conditions so as to achieve enhanced machining performance. The influence of machining parameters (feed rate) and tool type (cemented carbide, HSS and coated HSS) on thrust force in drilling of epoxy, epoxy/clay and epoxy/TiO2nanocomposites are investigated. Variation of input parameters, feed rate and tool type affects the thrust force. The cemented carbide tool creates less thrust force than HSS and coated HSS tools. The thrust force in drilling process of epoxy/TiO2nanocomposite was more significant than epoxy resin and epoxy/nano clay. The minimum thrust force (13 N) was obtained in feed rate of 0.02 mm/tooth in neat epoxy with carbide tool. پرونده مقاله -
دسترسی آزاد مقاله
27 - A Novel Optimization Approach Applied to Multi-Pass Turning Process
Amin Kolahdooz Hossein Towsyfyan Seyed Adnan Adnani Salehi Majed Ghayyem Farid MosaediOptimization of turning process is a non-linear optimization with constrains and it is difficult for theconventional optimization algorithms to solve this problem. The purpose of present study is todemonstrate the potential of Imperialist Competitive Algorithm (ICA) for چکیده کاملOptimization of turning process is a non-linear optimization with constrains and it is difficult for theconventional optimization algorithms to solve this problem. The purpose of present study is todemonstrate the potential of Imperialist Competitive Algorithm (ICA) for optimization of multipassturning process. This algorithm is inspired by competition mechanism among imperialists andcolonies, in contrast to evolutionary algorithmsthat perform the exploration and exploitation in thesolution space aiming to efficiently find near optimal solutions using a finite sequence ofinstructions. To validate the proposed approach, the results of ICA were finally compared withGenetic Algorithm (GA).Based on the results; ICA has demonstrated excellent capabilities such assimplicity, accuracy, faster convergence and better global optimum achievement. The outcomeshows the success of ICA in optimizing the machining process indicating that data analysis methoddeveloped in this work can be effectively applied to optimize machining processes. پرونده مقاله -
دسترسی آزاد مقاله
28 - Machinability evaluation of Titanium alloy in Laser Assisted Turning
Kamran Puladsaz Razavi Shojae Rezavi Mehdi TajaddaraThe use of titanium and its alloys has increased in various industries recently, because of their superior properties of these alloys. Titanium alloys are generally classified as difficult to machine materials because of their thermo-mechanical properties such as high s چکیده کاملThe use of titanium and its alloys has increased in various industries recently, because of their superior properties of these alloys. Titanium alloys are generally classified as difficult to machine materials because of their thermo-mechanical properties such as high strength-to-weight ratio and low thermal conductivity. Laser Assisted Machining (LAM) improves the machinability of high strength materials in various aspects. LAM is a high temperature cutting process using a laser beam as the heat source. The laser is used as an intense heat source to increase workpiece temperature locally and decrease the strength of the machined material in front of the cutting tool. Decreasing of workpiece material strengh in material removal region resulted to improvement of material removal conditions. In this study the effectiveness of the LAM on machinability of Ti6Al4V is invetigated by compared to conventional machining in varying process parameters such as cutting speed, feed rate, laser power and material removal temperature. The machinability of the titanium alloy under varying conditions is evaluated by examining specific cutting energy, surface roughness and chip morphology. This investigation has shown that LAM reduces specific cutting energy about 30% and improvement of surface roughness as compared to conventional machining. پرونده مقاله -
دسترسی آزاد مقاله
29 - Experimental Investigation of the Effect of Deionized Water on Surface Roughness of Near Dry Electro Discharge Machining of AISI D2 Steel
Mojtaba Taghizadeh Sayed Ali MosaviThe electro discharge machining (EDM), one of the methods used in the machining industry and a non-traditional manufacturing method, the electro erosion process does not depend on the hardness of material and offers a way to process materials of very complex geometry wi چکیده کاملThe electro discharge machining (EDM), one of the methods used in the machining industry and a non-traditional manufacturing method, the electro erosion process does not depend on the hardness of material and offers a way to process materials of very complex geometry with very fine and high precision by using cheap electrode materials, which make it a preferred method. In this study, effect of wet and near dry EDM has been investigated. Design of the experiment was chosen as full-factorial. Experimental data has been statistically analyzed and then appropriate model was extracted. The experimental results show that surface roughness decreases by increase of peak current and also pulse on-time; it should be mentioned that effect of peak current on surface roughness is greater than pulse on-time. Also by using near dry machining (NDM), surface roughness decreased about 1µm and approximately 15 percent. These indicate the good performance of NDM. پرونده مقاله -
دسترسی آزاد مقاله
30 - Intelligent Knowledge Based System Approach for Optimization of Design and Manufacturing for Abrasive Water Jet Machining
Morteza Sadegh AmalnikA water jet machining is an industrial tool capable of cutting a wide variety of materials using a very high-pressure jet of water, or a mixture of water and an abrasive substance. This paper addresses the concept of the Intelligent knowledge base system (IKBS) for opti چکیده کاملA water jet machining is an industrial tool capable of cutting a wide variety of materials using a very high-pressure jet of water, or a mixture of water and an abrasive substance. This paper addresses the concept of the Intelligent knowledge base system (IKBS) for optimization of product design and manufacturing process for water jet machining in computer based concurrent engineering environment. The I KBS links with feature library. The design specification is acquired through a feature based approach. The IKBS links with material data base which holds attributes of more than 20 type of materials. It also links with abrasive data base which hold attributes of 8 types of abrasive, and also 4 type and size of machine. IKBS is also links with machine data base which hold machine parameters. For each design feature, IKBS provides information needed for design and manufacturing optimization. The IKBS can be used as an advisory system for designers and manufacturing engineers. It can be used as a teaching program for new water jet operators in computer based concurrent engineering environment. پرونده مقاله -
دسترسی آزاد مقاله
31 - Micro Machining of AISI 440C Stainless Steel using Magnetic Field and Magnetic Abrasive Particles
Yahya Choopani Mohammad Reza RazfarMagnetic abrasive finishing (MAF) is a micromachining process that uses magnetic field and magnetic abrasive particles to conduct the mechanism of material removal in micro-nanometer scales. In this paper, by an experimental method and statistical analysis, the effects چکیده کاملMagnetic abrasive finishing (MAF) is a micromachining process that uses magnetic field and magnetic abrasive particles to conduct the mechanism of material removal in micro-nanometer scales. In this paper, by an experimental method and statistical analysis, the effects of parameters like working gap, work-piece rotational speed and material removal mechanism (injection of abrasive slurry of Al2O3) in the MAF process, on the external surfaces of cylindrical pieces of stainless steel (AISI 440C)were investigated on surface roughness. To do the experiments, a mechanism was designed and constructed. The results of this research show that the working gap and work-piece rotational speedhave a significant effect on the improvement of the surface roughness. It has been indicated that in vitro surface roughness improved 20% as a result of the gap working of 2 mm, workpiece rotational speed of 355 rpm, using the injection of abrasive slurry of Al2O3. پرونده مقاله -
دسترسی آزاد مقاله
32 - Intelligent Knowledge Based System Approach for Optimization of Design and Manufacturing Process for Wire-Electrical Discharge Machining
Morteza Sadegh AmalnikWire electrical discharge machining (WEDM) is a method to cut conductive materials with a thin electrode that follows a programmed path. The electrode is a thin wire. Typical diameters range from .004" - .012" (.10mm - .30mm) although smaller and larger diameters are av چکیده کاملWire electrical discharge machining (WEDM) is a method to cut conductive materials with a thin electrode that follows a programmed path. The electrode is a thin wire. Typical diameters range from .004" - .012" (.10mm - .30mm) although smaller and larger diameters are available. WEDM is a thermal machining process capable of accurately machining parts with varying hardness or complex shapes. WEDM process is based on electrical discharge machining (EDM) sparking phenomenon, utilizing the widely accepted non-contact technique of material removal. The hardness of the work piece material has no detrimental effect on the cutting speed. There is no physical contact between the wire and the part being machined. Rather, the wire is charged to a voltage very rapidly. This wire is surrounded by deionized water. When the voltage reaches the correct level, a spark jumps the gap and melts a small portion of the work piece. The deionized water cools and flushes away the small particles from the gap. This paper addresses the concept of WEDM and its parameters and development of an intelligent knowledge based system (IKBS) for WEDM in computer based concurrent engineering environment. The system links with a feature based CAD system in order to extract design data. The system is linked with databases. The machining cycle time, cost, material removal rate, and surface roughness of hole making are estimated for each selected design feature. The system provides useful information for product designers and manufacturing engineers and also advises manufacturing engineers to select optimum machining parameters. پرونده مقاله -
دسترسی آزاد مقاله
33 - Numerical/Experimental Analysis of the Deformation of Tubes under Concentrated Load
Javad Jafari Fesharaki Omid Rejali Seyed Ghasem MadaniDistortion and deformation of tubes during machining operations are very important. In this study, a tube used in magnetic drum separator under concentrated load (machining load) is considered. Using finite element simulation, deformities and their dependence on paramet چکیده کاملDistortion and deformation of tubes during machining operations are very important. In this study, a tube used in magnetic drum separator under concentrated load (machining load) is considered. Using finite element simulation, deformities and their dependence on parameters such as the thickness of the tube and the place of concentrated force are observed and predicted. To compare and confirm the results, some experimental tests are considered. The results show that there is good agreement between the numerical and experimental data. The results of this study indicate the amount of residual stress in the tube by changing the location of the load, the effect of residual stresses in the tube, indentations at different levels of thickness and location of the load. Results show that the values and location of force affect the stress and residual stress in the thickness of tube. In addition, increasing the thickness of tube decreases the residual stress area in longitudinal and circumferential direction of tube. Also, the maximum residual stress in tube is occurring under the force area and by increasing the thickness of tube, the displacements of area under the force is decreased. پرونده مقاله -
دسترسی آزاد مقاله
34 - The Analysis of Experimental Process of Production, Stabilizing and Measurement of the Thermal Conductivity Coefficient of Water/Graphene Oxide as a Cooling Nanofluid in Machining
Ramin Ranjbarzadeh Amir Homayoon Meghdadi Mohammad HojajiThe abrasion is a significant issue, especially in machining of rigid steels. A functional and suitable approach for enhancing the heat transfer from machining area is using an intermediate fluid with higher heat transfer potential instead of common fluids. The objectiv چکیده کاملThe abrasion is a significant issue, especially in machining of rigid steels. A functional and suitable approach for enhancing the heat transfer from machining area is using an intermediate fluid with higher heat transfer potential instead of common fluids. The objective of this experimental study is to discuss production, stability and thermal conductivity examination of water/graphene oxide nanofluid considered as a new nanofluid used in machining process instead of common coolant. In this research, for thermal conductivity enhancement of a basic fluid (Deionized water), a nanofluid development method composed of two steps as well as particles of nano dimension consisting water/graphene oxide is used. Producing 16 different nanofluid samples, the sample having a higher stability than others is considered for examining the thermal conductivity. The Zeta potential measurement is used in order to precisely determine stability of the final sample of water/graphene oxide nanofluid. Considering the obtained results, a highly acceptable level of stability is concluded. In addition, the transient hot wire method as well as thermal analyzer system is used to measure the heat transfer coefficient of water/graphene oxide nanofluid. According to the obtained results, the thermal conductivity of water/graphene oxide nanofluid in most states has increased to 71% compared to the base fluid. It is also observed that water/graphene oxide nanofluid has a high heat transfer potential. Utilizing this nanofluid enhances the heat transfer, improves the surface quality and reduces the damages caused by machining instrument. پرونده مقاله -
دسترسی آزاد مقاله
35 - An Experimental Investigation on Surface Roughness and Edge Chipping in Micro Ultrasonic Machining
Hamid ZarepourSurface quality including surface roughness and edge chipping is a key process measure in microultrasonic machining (Micro-USM) as an efficient process for micromachining of hard and brittlematerials. Process parameters such as ultrasonic vibration amplitude, static loa چکیده کاملSurface quality including surface roughness and edge chipping is a key process measure in microultrasonic machining (Micro-USM) as an efficient process for micromachining of hard and brittlematerials. Process parameters such as ultrasonic vibration amplitude, static load, type of toolmaterial, type and size of abrasive particles and slurry concentration can influence the surfacequality. However, there is limited study on the parametric effects on the surface quality in micro-USM. The objective of this study is to investigate the effects of the workpiece material as well asprocess parameters including abrasive type, particle size and vibration amplitude on surfaceroughness and edge chipping in micro-USM. Silicon, alumina ceramics and soda-lime glass wereselected as workpiece materials and polycrystalline diamond and alumina as abrasives. Particle sizeranging from 0.3 to 3 μm and vibration amplitude ranging from 0.8 to 3 μm were selected in thisstudy. Results indicate that workpiece material and vibration amplitude have significant effects onsurface roughness. Workpiece material was found to be the most significant parameter with apercentage contribution of about 45 % in the variation of mean Ra, followed by vibration amplitudeand particle size of about 28 % and 5% contributions, respectively. Results also show that aluminaceramic is a material capable of achieving better surface quality in micro-USM as compared tosilicon and soda-lime glass. پرونده مقاله -
دسترسی آزاد مقاله
36 - Development of Design and Manufacturing Support Tool for Optimization of Ultrasonic Machining (USM) and Rotary USM
Morteza Sadeghamalnik Mohammad Rasoul NajafiUltrasonic machining (USM) is a mechanical material removal process used to erode holes and cavities in hard or brittle work pieces by using shaped tools, high-frequency and an abrasive slurry. This paper addresses the concept and development of an expert system (ES) fo چکیده کاملUltrasonic machining (USM) is a mechanical material removal process used to erode holes and cavities in hard or brittle work pieces by using shaped tools, high-frequency and an abrasive slurry. This paper addresses the concept and development of an expert system (ES) for hard and brittle material, such as glass, quartz, diamond, carbides, semi conducting materials, ceramic and graphite which can be manufactured with ultrasonic machine or rotary ultrasonic machining. The expert system is developed based on object oriented technique. The system links with a feature based CAD system in order to extract design data. The expert system is linked with databases. The machining cycle time, cost, penetration rate and productivity, of each selected design feature are estimated. The system provides useful information such as machining cycle time and cost, penetration rate and efficiency of machining of the selected design feature for product designers and manufacturing engineers to select optimum machining parameters. Also the expert system compares ultrasonic machining (USM) and rotary ultrasonic machining (RUSM) for the same design feature in concurrent engineering environment. پرونده مقاله -
دسترسی آزاد مقاله
37 - Controlling Electrochemical Machining By Using a Fuzzy Logic Approach
Morteza Sadegh AmalnikNew trends and the effect of key factors influence the quality of the holes produced by ECMprocesses. Researchers developed a fuzzy logic controller by adding intelligence to the ECMprocess. Maintaining optimum ECM process conditions ensures higher machining efficiency چکیده کاملNew trends and the effect of key factors influence the quality of the holes produced by ECMprocesses. Researchers developed a fuzzy logic controller by adding intelligence to the ECMprocess. Maintaining optimum ECM process conditions ensures higher machining efficiency andperformance. This paper presents the development of a fuzzy logic controller to add intelligence tothe ECM process. An experimental ECM drilling was improved through the integration of a fuzzylogic controller into the existing control system. Matlab (Fuzzy Logic Toolbox) was used to build afuzzy logic controller system, which controls the feed rate of the tool and the flow rate of theelectrolyte. The objective of the fuzzy logic controller was to improve machining performance andaccuracy by controlling the ECM process variables. The results serve to introduce innovativepossibilities and provide potential for future applications of fuzzy logic control (FLC) in ECM.Hybrid controllers that integrate fuzzy logic into the control system allow for "human like"decision-making intelligence to be incorporated into ECM controllers. پرونده مقاله -
دسترسی آزاد مقاله
38 - Experimental Study of the Cutting Parameters Effect on Hole Making Processes in Hardened Steel
Navid Molla Ramezani Mojtaba Rezaei Hajideh Ali ShahmirzalooHardened steels are commonly used in wide areas of technologies and industries. In respect of poor machinability of these steels and requirement of expensive cutting tools, study of machining economy is a matter of importance. Thus the present study deals with the econo چکیده کاملHardened steels are commonly used in wide areas of technologies and industries. In respect of poor machinability of these steels and requirement of expensive cutting tools, study of machining economy is a matter of importance. Thus the present study deals with the economic considerations of various hole making processes. For this purpose, the hard steel samples were machined by conventional drilling and modern helical milling with and without predrilling. The experiments were performed on AISI D2 steel workpieces with a hardness of 52 HRC. The tool wear, surface roughness, cutting forces and machining time were measured. Results revealed that despite general knowledge, applying predrilling step is not a suitable strategy in hole making on hardened steels. Furthermore, helical milling enhances the efficiency of process by improvement of tool life and surface roughness and reducing the cutting forces. The aforementioned results make helical milling a more economical process than conventional drilling. پرونده مقاله -
دسترسی آزاد مقاله
39 - An experimental analysis and optimization of machining rate and surface characteristics in WEDM of Monel-400 using RSM and desirability approach
Vinod Kumar Vikas Kumar Kamal Kumar JangraIn the present work, an experimental investigation on wire electrical discharge machining (WEDM) of Monel-400 has been presented. Monel-400 is a nickel–copper-based alloy, mostly employed in ships and corrosion-resisting applications. Four input WEDM parameters na چکیده کاملIn the present work, an experimental investigation on wire electrical discharge machining (WEDM) of Monel-400 has been presented. Monel-400 is a nickel–copper-based alloy, mostly employed in ships and corrosion-resisting applications. Four input WEDM parameters namely discharge current (Ip), pulse-on time (Ton), pulse-off time (Toff) and servo voltage (SV) have been investigated and modeled for two performance characteristics namely machining rate (MR) and surface roughness (SR). Effect of WEDM parameters has been discussed using response surface graphs. Using analysis of variance, quadratic model is found significant for MR while two factors interaction (2FI) model has been suggested for SR. To optimize multi-performance characteristics, desirability function has been employed. Corresponding to highest desirability, the optimal combination of discharge parameters is Ip: 103A; Ton: 113μs; Toff: 37μs and SV: 50V. The effect of discharge energy on surface morphology has also been examined. High discharge energy increases the extent of surface damage and results in large size and overlapped craters on machined surface. Low discharge energy and high value of Toff result in minimum defects on machined surface. Trim cutting operations were performed at low discharge energy using different wire offset values. Result shows that surface finish can be improved significantly after a single trim cut irrespective of high discharge energy in rough cut. پرونده مقاله -
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40 - Multiple performance characteristics optimization for Al 7075 on electric discharge drilling by Taguchi grey relational theory
Reza Tavakkoli-Moghaddam Rajesh Khanna Anish Kumar Mohinder Pal Garg Ajit Singh Neeraj SharmaElectric discharge drill machine (EDDM) is a spark erosion process to produce micro-holes in conductive materials. This process is widely used in aerospace, medical, dental and automobile industries. As for the performance evaluation of the electric discharge drilling m چکیده کاملElectric discharge drill machine (EDDM) is a spark erosion process to produce micro-holes in conductive materials. This process is widely used in aerospace, medical, dental and automobile industries. As for the performance evaluation of the electric discharge drilling machine, it is very necessary to study the process parameters of machine tool. In this research paper, a brass rod 2mm diameter was selected as a tool electrode. The experiments generate output responses such as tool wear rate (TWR). The best parameters such as pulse on-time, pulse off-time and water pressure were studied for best machining characteristics. This investigation presents the use of Taguchi approach for better TWR in drilling of Al-7075. A plan of experiments, based on L27Taguchi design method, was selected for drilling of material. Analysis of variance (ANOVA) shows the percentage contribution of the control factor in the machining of Al-7075 in EDDM. The optimal combination levels and the significant drilling parameters on TWR were obtained. The optimization results showed that the combination of maximum pulse on-time and minimum pulse off-time gives maximum MRR. پرونده مقاله -
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41 - Multi-objective optimization in WEDM of D3 tool steel using integrated approach of Taguchi method & Grey relational analysis
Anand S. Shivade Vasudev D. ShindeIn this paper, wire electrical discharge machining of D3 tool steel is studied. Influence of pulse-on time, pulse-off time, peak current and wire speed are investigated for MRR, dimensional deviation, gap current and machining time, during intricate machining of D3 tool چکیده کاملIn this paper, wire electrical discharge machining of D3 tool steel is studied. Influence of pulse-on time, pulse-off time, peak current and wire speed are investigated for MRR, dimensional deviation, gap current and machining time, during intricate machining of D3 tool steel. Taguchi method is used for single characteristics optimization and to optimize all four process parameters simultaneously, Grey relational analysis (GRA) is employed along with Taguchi method. Through GRA, grey relational grade is used as a performance index to determine the optimal setting of process parameters for multi-objective characteristics. Analysis of variance (ANOVA) shows that the peak current is the most significant parameters affecting on multi-objective characteristics. Confirmatory results, proves the potential of GRA to optimize process parameters successfully for multi-objective characteristics. پرونده مقاله -
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42 - A model for tracking temperature variation in cold and hot metal working conditions during machining operations
S.A Oke I.O Oyedokun O.S Momodu O.G Akanbi F.A OyawaleThis paper presents a mathematical model that could assist in measuring, monitoring and controlling tem-perature variation in cold and ‘red-hot’ metal working conditions of machining. A numerical analysis tech-nique of the temperature distribution, based on چکیده کاملThis paper presents a mathematical model that could assist in measuring, monitoring and controlling tem-perature variation in cold and ‘red-hot’ metal working conditions of machining. A numerical analysis tech-nique of the temperature distribution, based on the theory of complex applied potential, was carried out using the principles of relationship analysis between the paths of heat supply in Cartesian plane when the heat path supplied to the material is orthogonal. The high level of temperature involved may effectively be predicted if a mathematical relationship that predicts the pattern of temperature distribution in a material is available. A case study example in a machining workshop is given. Simulation experiments are then carried out using Monte Carlo to increase the confidence in decision-making and provide data for significance testing. This was used as an input for testing for significance. Sensitivity analyses were also carried out in order to observe the degree of responsiveness of model parameters to changes in value. In all, five pairs of comparison were carried out among different workpiece materials. There are significant differences between workpiece materials made of steel and copper, copper and zinc, copper and aluminum. However, no significant differences exist in the model behavior of steel and aluminum, steel and zinc. It was observed that parameters are highly sensitive to changes in value. The framework could possibly be applied to milling and surfacing activities in the engineering workshop. This contribution may be helpful to small-scale enterprises that could not afford sophisticated and very expensive facilities. پرونده مقاله -
دسترسی آزاد مقاله
43 - ﺑﺮرﺳﯽ تأثیر ﭘﺎراﻣﺘﺮﻫﺎی ماشینکاری تخلیهالکتریکی، بر روی ماده مرکب پایه آلومینیوم 2024 با استفاده از تحلیل مقدار کل نرمال شده پارامترها (TNQL) و نسبت سیگنال به نویز (S/N)
بهنام مسعودی سعید دانشمندمواد مرکب زمینه فلزی با توجه به نوع تقویت کننده قابلیت ماشینکاری متفاوتی دارند. ماده مرکب الومینیوم 2024 تقویت شده با اکسید آلومینیوم از جمله موادی می باشد که ماشینکاری آن به روش های سنتی فرسایش سریع ابزار را در پی دارد. این روش ماشینکاری دارای پارامترهای مختلفی می باشد چکیده کاملمواد مرکب زمینه فلزی با توجه به نوع تقویت کننده قابلیت ماشینکاری متفاوتی دارند. ماده مرکب الومینیوم 2024 تقویت شده با اکسید آلومینیوم از جمله موادی می باشد که ماشینکاری آن به روش های سنتی فرسایش سریع ابزار را در پی دارد. این روش ماشینکاری دارای پارامترهای مختلفی می باشد. تنظیم بهینه پارامتر های ماشینکاری بر زمان، کیفیت محصول و سایش ابزار اثر مهمی دارد. در این تحقیق با استفاده از تحلیل مقدار کل نرمال شده پارامترها (TNQL) و نسبت سیگنال به نویز (S/N) همزمان خروجیها به بررسی تاثیر پارانترهای ورودی ماشینکاری تخلیه الکتریکی شامل شدت جریان، ولتاژ، زمان روشنی و خاموشی پالس بر نرخ براده برداری، سایش ابزار و زبری سطح در حالت بدون پودر و پودر و دوران ابزار پرداخته شده است. نتایج نشان داد که شدت جریان بیشترین و بعد از آن زمان روشنی، زمان خاموشی پالس و در آخر ولتاژ مهمترین اثر را بر پارامتر های خروجی ماشینکاری دارند. استفاده از پودر اکسید آلومینیوم و دوران ابزار باعث افزایش گپ و ایجاد نیروی گریز از مرکز شده و ذرات را به سرعت از منطقه ماشینکاری دور می کند و نرخ براده برداری افزایش می یابد. استفاده از پودر آلومینیوم در برخورد با جرقه ها باعث ریز تر شدن جرقه ها شده و عمق نفوذ آنها را کم نموده و در نتیجه زبری سطح کاهش می یابد. نتایج حاصل از بهینه سازی در حالت بدون پودر و دوران ابزار ترکیب پارامترها بهصورت A3B1C2D3 ودر حالت با پودر و دوران ترکیب پارامترها بهصورت A1B1C2D3 را پیشنهاد می کند. پرونده مقاله -
دسترسی آزاد مقاله
44 - ﺑﺮرﺳﯽ ماشینکاری تخلیهالکتریکی ماده مرکب آلومینیوم تقویت شده با نانو ذرات اکسید تیتانیوم
علی اکبر لطفی سعید دانشمندنانو ذرات مورد استفاده در مواد مرکب زمینه فلزی دارای انواع مختلف و خواص فیزیکی، شیمیایی و مکانیکی متفاوتی می باشند که باعث بهبود سختی، مقاومت مکانیکی، سایش و خواص دمایی می شوند و قابلیت های ماشینکاری مواد را تغییر می دهند. در این تحقیق به بررسی پارامترهای ماشینکاری تخلی چکیده کاملنانو ذرات مورد استفاده در مواد مرکب زمینه فلزی دارای انواع مختلف و خواص فیزیکی، شیمیایی و مکانیکی متفاوتی می باشند که باعث بهبود سختی، مقاومت مکانیکی، سایش و خواص دمایی می شوند و قابلیت های ماشینکاری مواد را تغییر می دهند. در این تحقیق به بررسی پارامترهای ماشینکاری تخلیه الکتریکی ماده مرکب الومینیوم تقویت شده با نانوذرات اکسید تیتانیوم پرداخته می شود. هدف از این تحقیق بررسی تاثیر شدت جریان، ولتاژ، زمان روشنی و خاموشی پالس و نانو ذرات اکسید تیتانیوم بر نرخ براده برداری، سایش ابزار و زبری سطح می باشد. از نفت سفید به عنوان دی الکتریک و الکترود مسی به عنوان ابزار و تجزیه و تحلیل واریانس برای اعتبار سنجی آزمایشگاهی استفاده می شود. نتایج نشان داد نانو ذرات سرامیکی اکسید تیتانیوم با توجه به ایتکه غیر هادی هستند تاثیر زیادی بر پارامترهای ماشینکاری ندارند و حین فرایند ماشینکاری تخلیه الکتریکی ذوب نمی شوند و شدت جریان و زمان روشنی بیشترین تاثیر بر نرخ براده برداری، سایش ابزار و زبری سطح دارند. با افزایش شدت جریان و زمان روشنی پالس سایش ابزار و زبری سطح زیاد شده و با افزایش زمان خاموشی پالس سایش ابزار کم می شود. به طور متوسط نرخ سایش الکترود ابزار در آلومینیوم 2024 تقویت شده با نانو ذرات اکسید تیتانیوم 5 درصد به میزان 46/3 درصد معادل 346/0گرم بیشتر از نمونه آلومینیوم 2024 از نظر وزنی است. پرونده مقاله -
دسترسی آزاد مقاله
45 - بررسی و بهینهسازی تأثیر پارامترهای ورودی بر نرخ براده برداری، نرخ سایش ابزار و زبری سطح در ماشینکاری تخلیه الکتریکی نانو کامپوزیت A356 تقویتشده با آلومینا
محمدجواد حاج حسینی علی مختاریان مجتبی رحیمی بهنام مسعودیدر این پژوهش، تأثیر پارامترهای ورودی ماشینکاری تخلیه الکتریکی بر روی نانو کامپوزیت A356 تقویت شده با 5/3% آلومینا (Al2O3)، با رویکرد طراحی آزمایش ها به روش تاگوچی بر مبنای آرایه متعامد L9 و تکنیک سطوح تکراری مورد بررسی و بهینه سازی قرار گرفت. پارامترهای ورودی این آزمای چکیده کاملدر این پژوهش، تأثیر پارامترهای ورودی ماشینکاری تخلیه الکتریکی بر روی نانو کامپوزیت A356 تقویت شده با 5/3% آلومینا (Al2O3)، با رویکرد طراحی آزمایش ها به روش تاگوچی بر مبنای آرایه متعامد L9 و تکنیک سطوح تکراری مورد بررسی و بهینه سازی قرار گرفت. پارامترهای ورودی این آزمایش ها شامل ولتاژ (دو سطحی)، شدت جریان (سه سطحی)، زمان روشنی پالس (سه سطحی) و زمان خـاموشی پـالس (سه سطحی) در نظر گرفته شد. همچنین، پـارامترهای خروجی شامل نـرخ براده برداری از قطعه کار، نرخ سایش ابزار ماشین کاری و زبری سطح قطعه کار بودند. تحلیل نتایج و بررسی نمودارهای سیگنال به نویز توسط نرمافزار انجام شد. همچنین با تعیین تابع زیان مقادیر نرمال شده کل پارامترهای خروجی بر مبنای ضرایب وزنی فرضی، سطح بهینه مربوط به هر پارامتر ورودی مشخص شد و با انجام آنالیز واریانس، میزان درصد سهم هر یک از پارامترهای ورودی در واریانس کل محاسبه شد. با توجه به نتایج حاصله، تأثیرگذارترین پارامتر ورودی بر روی نرخ براده برداری: زمان خاموشی پالس، بر روی نرخ سایش: ابزار شدت جریان و بر روی زبری سطح: زمان روشنی پالس تعیین شد. علاوه بر این، سطح اول ولتاژ (80 ولت)، سطح اول شدت جریان (10 آمپر)، سطح اول زمان روشنی پالس (35 میکروثانیه) و سطح دوم زمان خاموشی پالس (70 میکروثانیه) به عنوان سطوح بهینه پارامترهای ورودی تعیین شدند. درصد سهم پارامترهای ورودی در واریانس کل نیز برای ولتاژ، شدت جریان، زمان روشنی پالس و زمان خاموشی پالس به ترتیب برابر 98/12، 96/20، 47/5 و 60/60 به دست آمدند. پرونده مقاله -
دسترسی آزاد مقاله
46 - مطالعه اثر میدان مغناطیسی بر زبری سطح قطعهکار در ماشینکاری تخلیه الکتریکی ماده مرکب آلومینیوم 413 تقویت شده با آلومینا
احمدرضا میزبانی سیداحسان میرمحمدصادقی علی مختاریاندر این پژوهش، تأثیر پارامترهای ورودی ماشینکاری تخلیه الکتریکی بر روی زبری سطح قطعهکار از جنس ماده مرکب A413 تقویت شده با %5/2 Al2O3، در دو حالت با حضور میدان مغناطیسی و بدون وجود میدان مغناطیسی مورد بررسی و مقایسه قرار گرفته است. تحقیق ارائه شده با رویکرد طراحی آزمای چکیده کاملدر این پژوهش، تأثیر پارامترهای ورودی ماشینکاری تخلیه الکتریکی بر روی زبری سطح قطعهکار از جنس ماده مرکب A413 تقویت شده با %5/2 Al2O3، در دو حالت با حضور میدان مغناطیسی و بدون وجود میدان مغناطیسی مورد بررسی و مقایسه قرار گرفته است. تحقیق ارائه شده با رویکرد طراحی آزمایشات به روش تاگوچی بر مبنای آرایه متعامد L9 و تکنیک سطوح تکراری به انجام رسیده است. پارامترهای ورودی این آزمایشات شامل ولتاژ (دو سطحی)، شدتجریان (سه سطحی)، زمان روشنی پالس (سه سطحی) و زمان خاموشی پالس (سه سطحی) در نظر گرفته شده است. نتایج آزمایشات نشان دهنده کاهش زبری سطح ماشینکاری شده تا 32 درصد در حضور میدان مغناطیسی می باشد. تحلیل نتایج شامل تعیین نمودارهای نسبت سیگنال به نویز متناظر با هر یک از پارامترهای ورودی و آنالیز واریانس توسط نرمافزار Minitab صورت گرفته است. نتایج بدست آمده گویای بهبود کیفیت سطح قطعهکار در حضور میدان مغناطیسی در مقایسه با شرایط ماشینکاری بدون وجود میدان مغناطیسی است. همچنین برمبنای نتایج حاصل از آنالیز واریانس در هر دو حالت مذکور، شدت جریان مؤثرترین پارامتر ورودی بر روی زبری سطح قطعهکار از جنس ماده مرکب A413 تقویت شده با %5/2 Al2O3، تعیین شده است. پرونده مقاله -
دسترسی آزاد مقاله
47 - Investigation the Milling Strategies Effects on Machining of Convex Surfaces made of Glass/Epoxy Composite
هادی محمدی هادی اسکندری ایمان داناییIn this study the effects of machining parameters such as shearing speed, feed rate, tool diameter and machining depth on different milling strategies i.e. 3D offset, spiral, raster and radial to produce the convex surface made of epoxy/glass composites is investigated. چکیده کاملIn this study the effects of machining parameters such as shearing speed, feed rate, tool diameter and machining depth on different milling strategies i.e. 3D offset, spiral, raster and radial to produce the convex surface made of epoxy/glass composites is investigated. The effects of mentioned strategies on output parameters such as surface roughness and milling removal rate is also studied. The results show that the output of radial strategy has the minimum roughness with the highest surface quality. The raster strategy gives the maximum roughness with the lowest surface quality. Also it can be seen that in 3D offset strategy, the removal rate is maximum and subsequently the time of machining is minimum. In addition the optimized values of machining parameters to achieve the best conditions for surface smoothness and removal rate is obtained. The results of this work can be used in research and development units of industries for operational purposes. پرونده مقاله -
دسترسی آزاد مقاله
48 - Investigation and optimization of the effect of input parameters on output parameters of electrical discharge machining of A356 nano-composite reinforced by SiC
Amir Rahmani Ali Mokhtarian Mojtaba RahimiIn this study, the impact of input parameters of Electrical Discharge Machining (EDM) on A356 nano-composite reinforced by 6% SiC was investigated and optimized using Taguchi's method based on the L9 orthogonal array and duplicated levels method. We considered voltage, چکیده کاملIn this study, the impact of input parameters of Electrical Discharge Machining (EDM) on A356 nano-composite reinforced by 6% SiC was investigated and optimized using Taguchi's method based on the L9 orthogonal array and duplicated levels method. We considered voltage, current intensity, pulse on-time, and pulse off-time as the input parameters. Furthermore, material removal rate (MRR), tool wear rate (TWR), and surface roughness (SR) were taken into account as the output parameters. The analysis of results and examination of the signal-to-noise graphs (S/N) and analysis of variance (ANOVA) were performed using Minitab@16 software. Moreover, with the determination of the loss function of total normalized values of the output parameters based on assumed weight functions, the optimal level of each input parameter was established. Besides, the magnitude of contribution percentage of each of the input parameters in the total variance was computed through the variance analysis. According to the achieved results, the second level of the voltage (250 V), the first level of the current intensity (10 A), the third level of the pulse on-time (100 µs), and the first level of the pulse off-time (30 µs) were determined as the optimal input parameters. The contribution percentage of the input parameters for voltage, current intensity, pulse on-time, and pulse off-time was determined respectively to be 20.7, 62.06, 9.19, and 8.05. پرونده مقاله -
دسترسی آزاد مقاله
49 - Specifying the allowed remained bottom thickness after milling in CNG steel cylinders by FEM analysis and experimentation
Mojtaba Esmailian Mohsen Shahmoradi Kamran KarimzadehIn CNG steel cylinders produced by the hot spinning method from seamless tubes, homogeneity of the material in the closed-end region is a significant factor. Therefore, in the production process, the produced cups are immediately under a hot heavy press, and in addition چکیده کاملIn CNG steel cylinders produced by the hot spinning method from seamless tubes, homogeneity of the material in the closed-end region is a significant factor. Therefore, in the production process, the produced cups are immediately under a hot heavy press, and in addition to forming the bottom shape, the heterogeneous area is driven out, finally, this region is eliminated via machining. Ideally, the depth of this milled area should be to the extent that the heterogeneous region is completely removed, also according to the designing standards, the minimum bottom thickness shall be more than that of wall thickness. However, the problem is that controlling this parameter is impossible in the machining process, and in some cases, it may become more than the specified limit. In this research, the minimum allowed remained thickness after bottom milling has been obtained by analysis and also compared with real results acquired from static and fatigue tests. Deducing the results of the FEM analysis, it can be seen that the remained bottom thickness up to 6mm has no limitation for the endurance hydrostatic pressure, and that was supported by experimental burst tests. Considering this amount for the bottom thickness, the percentage of rejected products declined considerably from 4% to 2% in the factory. پرونده مقاله -
دسترسی آزاد مقاله
50 - Influence of EDM Characteristic Parameters on the Surface Microstructure in CK45 Alloy Steel
سینا عابدپور اسماعیل جعفری احمد افسری سعید حدیدی مودElectro Discharge Machining (EDM) is a very efficient machining process widely used in manufacturing components of complicated geometry. Based on its nature, i.e. material removal by electric discharge, the process induces thermal stresses that in turn result in generat چکیده کاملElectro Discharge Machining (EDM) is a very efficient machining process widely used in manufacturing components of complicated geometry. Based on its nature, i.e. material removal by electric discharge, the process induces thermal stresses that in turn result in generation of wide spread micro-cracks on the surface of the machined part. In this paper the influence of EDM characteristic parameters on the surface microstructure in CK45 alloy steel which is suitable for manufacturing of forging dies has been extensively investigated. An extensive experimental programme has been carried out to explore the role of various EDM parameters on the quality of the machined surface. The relation of EDM parameters has been evaluated quantitatively using the test results and regression analysis. Predicting the impact of EDM parameters on the surface quality as the outcome of this study provides means to appropriately decide on the adjustment of parameters to their optimum values and achieve the desired die surface quality at reasonable manufacturing time and cost. پرونده مقاله -
دسترسی آزاد مقاله
51 - Evaluation of Tool Performance With Nanocrystalline Multilayer Coatings on the Machinability of Superalloy Inconel 718
رسول مختاری همامی بهروز موحدی ایرج لیرابی مهدی بازرگان حقیقیIn this paper, the performance of the cutting tool with nanocrystalline multilayer coatings (TiN+TiAlN) for machining of superalloy Inconel 718 in the dry and wet conditions was studied. The multi layer TiN and TiAlN with nanocrystalline structure was applied by physica چکیده کاملIn this paper, the performance of the cutting tool with nanocrystalline multilayer coatings (TiN+TiAlN) for machining of superalloy Inconel 718 in the dry and wet conditions was studied. The multi layer TiN and TiAlN with nanocrystalline structure was applied by physical vapor deposition technique (arc evaporation) on the WC-Co inserts. The results of the ball on disc wear test and the machining of superalloy Inconel 718 in wet and dry conditions indicated that the nanocrystalline coatings could produce better performance of tools in turning. Abrasion and adhesive wear resistance improved by nanocrystalline and modified Aluminum composition in TiAlN coating as well as toughness and thermal stability. پرونده مقاله -
دسترسی آزاد مقاله
52 - The Effect of Electrical Discharge Machining Parameters on Alloy DIN 1.2080 Using the Taguchi Method and Optimal Determinant
پویان صدر امین کلاه دوز علی افتخاریElectrical discharge machining process, is one of the most widely used methods for machining, the electrically conductive parts. In this way the tool is not in contact with the workpiece and the hardness of workpiece does not affect the machining speed. In Electrical Di چکیده کاملElectrical discharge machining process, is one of the most widely used methods for machining, the electrically conductive parts. In this way the tool is not in contact with the workpiece and the hardness of workpiece does not affect the machining speed. In Electrical Discharge Machining process, selection of the correct machining parameters are effective in final cost and the quality of the products. The special application of this alloy in various industries including tooling industry is attributed to its high hardness and wear resistance. The DIN 1.2080 steel at low temperature has a high wear resistance. Its hardness depth is high and it is suitable for machining at low temperature. In this paper, the effect of the type and setting parameters and determination of optimal levels in of electrical discharge machining of alloy DIN 1.2080 using the Taguchi method and optimal determinant is examined The desired setting parameters including gap voltage, current intensity, on time and off time. The material removal rate and surface roughness of produced parts as the output characteristic of the study were investigated. Results showed that the spark current is more effective on the output parameter (more than 65% on material removal rate and more than 48% on a surface roughness), Other effective parameters are pulse on time, pulse off time and voltage changes, respectively. Higher current and pulse on time values and lower voltage and pulse off time values result in high MRR and low SR پرونده مقاله -
دسترسی آزاد مقاله
53 - Optimization of Material Removal Rate in Electrical Discharge Machining Alloy on DIN1.2080 with the Neural Network and Genetic Algorithm
مسعود عظیمی امین کلاه دوز سید علی افتخاریElectrical discharge machining process is one of the most Applicable methods in Non-traditional machining for Machining chip in Conduct electricity Piece that reaching to the Pieces that have good quality and high rate of machining chip is very important. Due to the rap چکیده کاملElectrical discharge machining process is one of the most Applicable methods in Non-traditional machining for Machining chip in Conduct electricity Piece that reaching to the Pieces that have good quality and high rate of machining chip is very important. Due to the rapid and widespread use of alloy DIN1.2080 in different industry such as Molding, lathe tools, reamer, broaching, cutting guillotine, etc. Reaching to optimum condition of machining is very important. Therefore the main aim in this article is to consider the effect of input parameter such voltage, Current strength, on-time pulse and off-time pulse on the machining chip rate and optimizing this in the electrical discharge machining for alloy DIN1.2080. So to reach better result after doing some experiments to predict and optimize the rate of removing chip, neural network method and genetic algorithm are used. Then optimizing input parameters to maximize the rate of removing chip are performed. In this condition, by decreasing time, the product cost is decreased. Optimum parameters in this experiment in this condition are obtained under Current strength 20 ampere, 160 volt, on-time pulse 100 micro second and off-time pulse 12 micro second that is obtained 0.063 cm3/min as rate of machining chip. After doing experiment, surveying the level of error and its accuracy are evaluated. According to the obtained error value that is about 5.18%, used method is evaluated for genetic algorithm پرونده مقاله
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