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Open Access Article
1 - Numerical and Experimental Investigation of Thickness Variation in the Spinning Process of Al-1060 Alloy
Mohammad Honarpisheh Shayan Namazikhah Iman AlinaghianMetal spinning as a kind of manufacturing process has capability to shape hollow components. In present work shear spinning process is used to formplates into conical shapes. Moreover, the aim of this research is to demonstrate the impact of the process parameters (i.e. MoreMetal spinning as a kind of manufacturing process has capability to shape hollow components. In present work shear spinning process is used to formplates into conical shapes. Moreover, the aim of this research is to demonstrate the impact of the process parameters (i.e. feeding rate and spindle speed) on wall thickness. This approachwas done by experimental and finite elements method. The results illustrated that wall thickness decreases while feeding rate increases in spinning process. The experimental results confirm the Finite element analysis (FEA) results during thickness evaluations so this shows that FEA results are reliable for this specific case. The results of analysis reveals that the best condition for spinning is for feeding rate of 40 mm/min and spindle speed of 50 rpm in which highest thickness of 1mm is obtained. In consequence, the findings also illustrated that by decreasing the feeding rate and spindle speed, higher thickeners can be observed during shear spinning process. Manuscript profile -
Open Access Article
2 - Experimental Passive Suppression of the Regenerative Chatter Phenomenon by Variation of the Frequency and Amplitude of the Spindle Motor Excitation in Turning
Kamyar Foroojani Zadeh Reza NosouhiThe suppression of the regenerative chatter phenomenon in turning process via the variation of the frequency and amplitude of the spindle motor excitation is carried out in this research. A programmable inverter is employed for variable periodic excitation of the spindl MoreThe suppression of the regenerative chatter phenomenon in turning process via the variation of the frequency and amplitude of the spindle motor excitation is carried out in this research. A programmable inverter is employed for variable periodic excitation of the spindle motor. A set of turning experiments is designed and performed on a number of conical work pieces both in constant spindle speeds and variable spindle speeds. The work-piece material was 1.7224 steel. These experiments are carried out in different spindle speeds so that the stability lobes diagram could be achieved. The results showed that the passive variations of the spindle speed increase the critical depth of cut in higher spindle speeds, while in lower spindle speeds it is case sensitive. It also showed that the increasing of the excitation frequency reduces the critical depth of cut, while increasing the amplitude increases the critical chip thickness in lower spindle speeds and reduces that in higher spindle speeds. ated that by decreasing the feeding rate and spindle speed, higher thickeners can be observed during shear spinning process. Manuscript profile -
Open Access Article
3 - Dry Friction and Wear Performance of Micro Surface Textures Generated by Ultrasonic Assisted Face Turning
Hossein Nouri Hosseinabadi Masoud FarahnakianNowadays the surface texturing has been widely recognized as a usable capability to improve the tribological systems. In this paper, ultrasonic assisted turning (UAT) isperformed to create the micro textures on the flat faces. Micro surface texturing ismade on the Al707 MoreNowadays the surface texturing has been widely recognized as a usable capability to improve the tribological systems. In this paper, ultrasonic assisted turning (UAT) isperformed to create the micro textures on the flat faces. Micro surface texturing ismade on the Al7075-T6 by the UAT in the face turning process. Then, the influences of cutting speed feed, vibration direction and vibration amplitudeare studied.The effects of process parameterson the friction and wear behaviors of un-textured and textured patterns areinvestigated by the full factorial method. Microscopic images demonstrate the creation of micro dimples on the surfaces.Experimental results showed that textured surfaces can decrease the average friction coefficient and wear rate. The friction coefficient of surfaces generated by the UAT processwasdecreased about 10% in comparison to surfaces generated by conventional face turning.Moreover, because of existence of micro-dimple arrays in surfaces generated by the UAT process, proportion of contact between the pins and textured surfaces reduces. Cutting speed and feed effect on both of the average friction coefficient and wear rate.By increasingofthe cutting speed, feed, vibration amplitude and vibration direction (angle), the average friction coefficient and wear reduce. Manuscript profile -
Open Access Article
4 - Investigation of the Microscopic Aspect of the Stress Distribution in the Accumulative Roll Bonding Process Using the Slab Method
Mohammad Heydari Vini Pedram FarhadipourThe accumulative roll bonding (ARB) as a severe plastic deformation (SPD) procedure aimed at enhancing the mechanical properties of metals and alloys. In the present study, a new slab method is proposed for estimating the forming stress field for cold extrusion of metal MoreThe accumulative roll bonding (ARB) as a severe plastic deformation (SPD) procedure aimed at enhancing the mechanical properties of metals and alloys. In the present study, a new slab method is proposed for estimating the forming stress field for cold extrusion of metals cross the alumina interlayer powder particles by accumulative roll bonding process. Plastic deformation behavior of the metal at the interfaces of the strips was investigated. Distinctive particles arrangements are used for different zones in the extrusion channel in the present models and the forming stress during the extrusion process affected. The corresponding results have also been determined analytically and by using the finite element software, ABAQUS. It was found that the theoretical prediction of the forming stress of the extruded metal cross the interlayer particles is in good compliance with the numerical measurement. Moreover, the interfaces of laminates have been studied to investigate the behavior of particles by scanning electron microscopy (SEM). Manuscript profile -
Open Access Article
5 - 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 MoreSurface 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. Manuscript profile -
Open Access Article
6 - Simulation and Analysis of the New Brake System according to Changing of the Spring and Vertical Acceleration of the Wheels
Bahman Karami Pirmohammadi Mehdi TajdariMoving car on rough road suddenly gets out of its way for some reason and moves to the edge ofthe road at the same speed. Since the most important factor in car overturning is verticalacceleration in the wheels and car speed and road conditions determine the vertical in MoreMoving car on rough road suddenly gets out of its way for some reason and moves to the edge ofthe road at the same speed. Since the most important factor in car overturning is verticalacceleration in the wheels and car speed and road conditions determine the vertical instantaneousacceleration, brake system according to change of the spring length is designed in such a way thatby monitoring the instantaneous acceleration at the wheels, by interrupting the speeding up andapplying the anti-lock braking, this can prevent cars overturning. By placing the sensor on rings ofthe spring, we can send the changing moment of the spring to the ABS control unit. The sensorwhich was a kind of Electromagnetic sensors providing these conditions to control the car withprecise circuit design at the Simulink section in CARSIM software and three-step interface circuitbetween the sensor and ABS brakes at Proteus software. In Simulink software the data that islogged as input has car maneuver variables such as longitudinal speed of the car, which afterprocessing the instantaneous information obtained during maneuvering, variables such as pressurein the wheel brake cylinders, are sent to CARSIM software as the output of the system to continuethe maneuvering. At Simulink model is designed in three parts that include: designing of simulatedcar in the software with the existing parameters, control boxes circuit and also switch boxes forsystem operators which have their task. First, the car goes straight in normal maneuvers, and then itwould be tested in the rugged pathways. In this condition, the success and failure of themaneuvering are checking by the equipping and not equipping the car. After these tests, the rightreal way would be selected and the road will be more completed by placing screws and soilshoulder and margins. Manuscript profile
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