Hamid Zarepour | Islamic Azad University, Najafabad Branch (original) (raw)
Papers by Hamid Zarepour
Surface quality including surface roughness and edge chipping is a key process measure in micro u... more Surface quality including surface roughness and edge chipping is a key process measure in micro ultrasonic machining (Micro-USM) as an efficient process for micromachining of hard and brittle materials. Process parameters such as ultrasonic vibration amplitude, static load, type of tool material, type and size of abrasive particles and slurry concentration can influence the surface quality. 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 as process parameters including abrasive type, particle size and vibration amplitude on surface roughness and edge chipping in micro-USM. Silicon, alumina ceramics and soda-lime glass were selected as workpiece materials and polycrystalline diamond and alumina as abrasives. Particle size ranging from 0.3 to 3 µm and vibration amplitude ranging from 0.8 to 3 µm were selected in this study. Results indicate that wo...
ASME 2011 International Manufacturing Science and Engineering Conference, Volume 1, 2011
Surface integrity, mechanical deformation, and thermal deformation are among the crucial error ge... more Surface integrity, mechanical deformation, and thermal deformation are among the crucial error generation factors in tool-based micromachining the influence of which should be minimized. As a micromachining process, micro ultrasonic machining (micro-USM) must satisfy the above considerations. In micro-USM, material is removed by fine and free abrasive particles inside a fluid; hence, there is no direct contact between micro-tool and the workpiece. Furthermore, no thermal damage is induced into the machined surface. Therefore, this process can satisfy the requirements of minimum mechanical and thermal deformation as a tool-based micromachining process. However, usually a rather course surface with subsurface microcracks is generated by USM processes. As such, study on surface characteristics and improvement of surface quality in micro-USM is considered necessary in order to introduce this process as a mature micromachining process. In this paper, the effect of various process paramet...
Advanced Materials Research, 2009
In this paper, the effect of machining parameters including cutting velocity, feed rate, and tool... more In this paper, the effect of machining parameters including cutting velocity, feed rate, and tool material on machining power of EN-AC 48000 aluminium alloy has been studied. A L 27 Taguchi's standard orthogonal array has been applied as experimental design to investigate the effect of the factors and their interaction. Twenty seven machining tests have been accomplished with two random repetitions, resulting in fifty four experiments. EN-AC 48000 is an important alloy in automotive and aerospace industries. Machining of this alloy is of vital importance due to build-up edge and tool wear. Machining power is an essential parameter affecting the tool life, dimensional accuracy, and cutting efficiency. Three types of cutting tools including coated carbide (CD 1810), uncoated carbide (H10), and polycrystalline diamond (CD10) have been used in this study. Statistical analysis has been employed to study the effect of factors and their interactions using ANOVA analysis. Moreover, optimal factor levels have been presented using signal to noise ratio (S/N) analysis. Also, regression model have been provided to predict the machining power. Finally, the results of confirmation tests have been presented to verify and compare the adequacy of the predictive models.
Handbook of Manufacturing Engineering and Technology, 2014
Grinding is finishing process aimed at achieving su rface quality and dimensional accuracy in wor... more Grinding is finishing process aimed at achieving su rface quality and dimensional accuracy in workpieces with tight tolerances especially from ma teri ls with a high degree of hardness and strength. The grinding process of superalloys is fa ced with problems and challenges caused by the generation of excessiveheatas well as the adhesion of workpiecematerialon the grinding tool. Therefore, in-depth research is still under way to introduce and develop new techniques for optimization of output parameters in the grinding o f superalloys. One of such techniques is to apply minimum quantity lubrication (MQL) using nanofluids . In this research, we study the effect of using a ty pe of mixed nanofluid comprising multiwall carbon nanotubes (MWCNT) and nano-aluminum oxide (Al 2O3) on the surface quality in the grinding process of Inconel 600.For this purpose, the input parameters of the process are first determined. Following that, the design of experiments were perf ormed based on full facto...
To address surface quality challenges in the diamond wire sawing process we investigate the effec... more To address surface quality challenges in the diamond wire sawing process we investigate the effect of superimposed short-amplitude (few micrometers) high frequency (100s of Hz) linear vibrations using two setups: one involving scratching of monocrystalline silicon using a diamond tool tip in a tribometer and the second involving wire sawing using closed-loop fixed-abrasive diamond wire setup. Linear vibrations are generated through a piezoactuator and transmitted to an in-house built tool holder with the resonant frequency of about 486 Hz. Scratch tests in the tribometer were conducted at three different frequencies, namely, resonant frequency (486 Hz), a non-resonant frequency (2000 Hz), and without any vibration. Diamond wire sawing tests were conducted with and without vibration (486 Hz). In general, the superimposed vibrations resulted in significant differences in the quality of the scratched and sawn surfaces. Some intermittent patterns or tool marks are observed in scratches ...
Advanced Materials Research, 2009
Surface quality including surface roughness and edge chipping is a key process measure in micro u... more Surface quality including surface roughness and edge chipping is a key process measure in micro ultrasonic machining (Micro-USM) as an efficient process for micromachining of hard and brittle materials. Process parameters such as ultrasonic vibration amplitude, static load, type of tool material, type and size of abrasive particles and slurry concentration can influence the surface quality. 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 as process parameters including abrasive type, particle size and vibration amplitude on surface roughness and edge chipping in micro-USM. Silicon, alumina ceramics and soda-lime glass were selected as workpiece materials and polycrystalline diamond and alumina as abrasives. Particle size ranging from 0.3 to 3 µm and vibration amplitude ranging from 0.8 to 3 µm were selected in this study. Results indicate that wo...
ASME 2011 International Manufacturing Science and Engineering Conference, Volume 1, 2011
Surface integrity, mechanical deformation, and thermal deformation are among the crucial error ge... more Surface integrity, mechanical deformation, and thermal deformation are among the crucial error generation factors in tool-based micromachining the influence of which should be minimized. As a micromachining process, micro ultrasonic machining (micro-USM) must satisfy the above considerations. In micro-USM, material is removed by fine and free abrasive particles inside a fluid; hence, there is no direct contact between micro-tool and the workpiece. Furthermore, no thermal damage is induced into the machined surface. Therefore, this process can satisfy the requirements of minimum mechanical and thermal deformation as a tool-based micromachining process. However, usually a rather course surface with subsurface microcracks is generated by USM processes. As such, study on surface characteristics and improvement of surface quality in micro-USM is considered necessary in order to introduce this process as a mature micromachining process. In this paper, the effect of various process paramet...
Advanced Materials Research, 2009
In this paper, the effect of machining parameters including cutting velocity, feed rate, and tool... more In this paper, the effect of machining parameters including cutting velocity, feed rate, and tool material on machining power of EN-AC 48000 aluminium alloy has been studied. A L 27 Taguchi's standard orthogonal array has been applied as experimental design to investigate the effect of the factors and their interaction. Twenty seven machining tests have been accomplished with two random repetitions, resulting in fifty four experiments. EN-AC 48000 is an important alloy in automotive and aerospace industries. Machining of this alloy is of vital importance due to build-up edge and tool wear. Machining power is an essential parameter affecting the tool life, dimensional accuracy, and cutting efficiency. Three types of cutting tools including coated carbide (CD 1810), uncoated carbide (H10), and polycrystalline diamond (CD10) have been used in this study. Statistical analysis has been employed to study the effect of factors and their interactions using ANOVA analysis. Moreover, optimal factor levels have been presented using signal to noise ratio (S/N) analysis. Also, regression model have been provided to predict the machining power. Finally, the results of confirmation tests have been presented to verify and compare the adequacy of the predictive models.
Handbook of Manufacturing Engineering and Technology, 2014
Grinding is finishing process aimed at achieving su rface quality and dimensional accuracy in wor... more Grinding is finishing process aimed at achieving su rface quality and dimensional accuracy in workpieces with tight tolerances especially from ma teri ls with a high degree of hardness and strength. The grinding process of superalloys is fa ced with problems and challenges caused by the generation of excessiveheatas well as the adhesion of workpiecematerialon the grinding tool. Therefore, in-depth research is still under way to introduce and develop new techniques for optimization of output parameters in the grinding o f superalloys. One of such techniques is to apply minimum quantity lubrication (MQL) using nanofluids . In this research, we study the effect of using a ty pe of mixed nanofluid comprising multiwall carbon nanotubes (MWCNT) and nano-aluminum oxide (Al 2O3) on the surface quality in the grinding process of Inconel 600.For this purpose, the input parameters of the process are first determined. Following that, the design of experiments were perf ormed based on full facto...
To address surface quality challenges in the diamond wire sawing process we investigate the effec... more To address surface quality challenges in the diamond wire sawing process we investigate the effect of superimposed short-amplitude (few micrometers) high frequency (100s of Hz) linear vibrations using two setups: one involving scratching of monocrystalline silicon using a diamond tool tip in a tribometer and the second involving wire sawing using closed-loop fixed-abrasive diamond wire setup. Linear vibrations are generated through a piezoactuator and transmitted to an in-house built tool holder with the resonant frequency of about 486 Hz. Scratch tests in the tribometer were conducted at three different frequencies, namely, resonant frequency (486 Hz), a non-resonant frequency (2000 Hz), and without any vibration. Diamond wire sawing tests were conducted with and without vibration (486 Hz). In general, the superimposed vibrations resulted in significant differences in the quality of the scratched and sawn surfaces. Some intermittent patterns or tool marks are observed in scratches ...
Advanced Materials Research, 2009