فهرس المقالات Process Parameters

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  1 - Functionally Graded Thermal Spray Coatings: Methods, Parameters, and Post-Spray Treatments
  A Rabieifar M, R Tavighi
  Surface coating on metal substrates has remained a difficult challenge for researchers due to the conflicting requirements for different properties. In recent years, due to their mechanical, thermal, electrical, and tribological properties in many advanced engineering a أکثر

  Surface coating on metal substrates has remained a difficult challenge for researchers due to the conflicting requirements for different properties. In recent years, due to their mechanical, thermal, electrical, and tribological properties in many advanced engineering applications, functionally graded coatings (FGCs) have become fascinating materials for researchers worldwide to obtain coatings with specific requirements. FGCs are a novel type of traditional composites in which phases are not equally distributed to form a smooth gradient structure; thus, gradient coatings have shown a new research path.The present paper tries to describe briefly major thermal spray techniques used to spray functionally graded coatings such as atmospheric plasma spraying, high velocity oxy-fuel spraying, suspension and solution precursor plasma spraying, and finally low and high-pressure cold gas spray methods. The examples of combined spray processes as well as some examples of post-spray treatment including laser and high temperature treatments or mechanical ones, are described. تفاصيل المقالة
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  2 - Investigation of Additive Manufacturing Process by LMD Method, Affecting Process Parameters on Microstructure and Quality of Deposition Layers
  R Hedayatnejad H Sabet S Rahmati A Salemi Golezani
  Additive manufacturing (AM) is a general name used for production methods which have the capabilities of producing components directly from 3D computer aided design (CAD) data by adding material layer-by-layer until a final component is achieved. Included here are powde أکثر

  Additive manufacturing (AM) is a general name used for production methods which have the capabilities of producing components directly from 3D computer aided design (CAD) data by adding material layer-by-layer until a final component is achieved. Included here are powder bed technologies, laminated object manufacturing and deposition technologies. These technologies are presently used for various applications in engineering industry as well as other areas of society, such as medicine, aerospace, architecture, cartography, entertainment. Laser metal deposition (LMD) using powder as an additive is an AM process which uses a multi-axis computer numerical control (CNC) machine to guide the laser beam and powder nozzle over the deposition surface. The component is built by depositing adjacent beads layer by layer until the component is completed. LMD has lately gained attention as a manufacturing method which can add features to semi-finished components or as a repair method. LMD introduce a low heat input compared to arc welding methods and is therefore well suited in applications where a low heat input is of an essence. For instance, in repair of sensitive parts where too much heating compromises the integrity of the part. It has been found that the most influential process parameters are the laser power density, scanning speed, powder feeding rate and powder standoff distance and that these parameters has a significant effect on the characteristics of the material such as microstructure تفاصيل المقالة
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  3 - Process Parameters Optimization in Gas Blow Forming of Pin-type Metal Bipolar Plates using Taguchi and Finite Element Methods
  M. Moradian A. Doniavi V. Modanloo V. Alimirzaloo
  Metal bipolar plates are the most important parts of the fuel cells and recently these plates are used instead of graphite ones.In the present study, gas blow forming of a pin-type aluminum 5083 bipolar plate has been studied. After the simulation of the process, the FE أکثر

  Metal bipolar plates are the most important parts of the fuel cells and recently these plates are used instead of graphite ones.In the present study, gas blow forming of a pin-type aluminum 5083 bipolar plate has been studied. After the simulation of the process, the FE model has been validated using experimental results. Then, the effects of parameters including maximum pressure of the gas, pressurization profile and corner radius of the pin on thinning ratio and forming depth of final part have been investigated. Nine experiments were designed using the Taguchi L9 orthogonal array and the experiments were performed using the FE model. The signal to noise (S/N) ratio and the analysis of variance (ANOVA) techniques were carried out to determine the effective parameters and the contribution of each parameter. The maximum pressure of 1.2 MPa, SP2 pressurization profile and corner radius of 0.2 mm lead to the minimum thinning ratio. Also, it was found that to maximize the forming depth, the maximum pressure of 2 MPa, SP1 pressurization profile and corner radius of 0.3 mm should be selected. Also, ANOVA analysis showed that the most significant parameters on thinning ratio and forming depth are corner radius and maximum pressure, respectively. تفاصيل المقالة
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  4 - Hole-flanging of 2205 Dual-Phase Steel using Incremental Forming Process
  Amir H. Roohi Seyed Jalal Hashemi
  10.30495/admt.2021.1895361.1179
  In this study, hole-flanging of a dual-phase steel sheet is conducted using incremental forming approach. In this process, a hole with a certain diameter is pre-cut on a sheet. Then, this hole is transformed into a cylindrical flange shapes, by contacting the forming to أکثر

  In this study, hole-flanging of a dual-phase steel sheet is conducted using incremental forming approach. In this process, a hole with a certain diameter is pre-cut on a sheet. Then, this hole is transformed into a cylindrical flange shapes, by contacting the forming tool with the hole edges. During the process, the tool is moved in spiral paths. The parameters affecting the height and thickness distribution of the formed flange include axial step, radial step, and rotational speed of the tool. Results show that the axial step has the most significant effect on the process, among other parameters; when the axial step is tripled, the flange thickness increases by 19%. On the other hand, a decrease in the radial step decreases the flange edge thickness. When the radial step is tripled, the flange thickness increases by 8%, while the flange height decreases about 3%. تفاصيل المقالة
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  5 - An Experimental Investigation on Surface Roughness and Edge Chipping in Micro Ultrasonic Machining
  Hamid Zarepour
  Surface 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 أکثر

  Surface 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. تفاصيل المقالة
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  6 - A two-sided Bernoulli-based CUSUM control chart with autocorrelated observations
  S. M. T. Fatemi Ghomi F. Sogandi
  Usually, in monitoring a proportionp , the binary observations are considered independent; however, in many real cases, there is a continuous stream of autocorrelated binary observations in which a two-state Markov chain model is applied with first-order dependence. On أکثر

  Usually, in monitoring a proportionp , the binary observations are considered independent; however, in many real cases, there is a continuous stream of autocorrelated binary observations in which a two-state Markov chain model is applied with first-order dependence. On the other hand, the Bernoulli CUSUM control chart which is not robust to autocorrelation can be applied two-sided control chart to able to detect either increases or decreases in the process parameter. In this paper, a two-sided Bernoulli-based CUSUM control chart is proposed based on a log-likelihood-ratio statistic using a Markov chain model and average run length relationship. The average run length relationship is set using the corresponding upper and lower Bernoulli CUSUM charts. Simulation studies show the superior performance of the proposed monitoring scheme. Numerical results show the superior performance of the proposed control chart. تفاصيل المقالة