Papers by Author: Mohammad Reza Shabgard

Abstract: This paper details the correlation between the input parameters with the tool material on the machining response in comparison of two different combinations of toolworkpiece material, namely copper-H13 and graphite-H13. The considered machining input parameters included pulse current and pulse on-time, and the investigated characteristics of the machining response were the material removal rate, tool wear, and surface roughness of the workpiece. Furthermore, differences in pulse shapes and process stability between the copper-H13 and graphite-H13 combinations were investigated.

Abstract: This paper presents the results of experimental studies carried out to conduct a comprehensive investigation on the influence of tool material on the characteristics of Electrical Discharge Machining process of AISI H13 tool steel. The studied process characteristics included the tool wear ration and thickness of the white layer on the workpiece after the EDM process. The experiments carried out under the designed full factorial procedure and the considered EDM input parameters included pulse on-time and pulse current. The results of this study could be utilized to choice a set of pulse on-time and pulse current according to the outcomes that suit the requirements of tool-workpiece combination processed by the EDM.

Abstract: The correct selection of the machining parameters is one of the most significant issues to take into consideration in Ultrasonic-assisted Electrical Discharge Machining (US-EDM) and EDM processes. In the present work, a study has been made to develop and extract statistical models to show the relationship between important machining performance data (material removal rate (MRR), tool wear ratio (TWR) and surface roughness Ra) and the input machining parameters (pulse current, and pulse-on time) in the EDM and US-EDM of AISI H13. The models obtained were used to analyze the effects of input parameters on machining performance. In addition, a comparative study was carried out to investigate the effect of ultrasonic vibration of the workpiece on machining performance. The results show that Ultrasonic vibration of the workpiece can significantly reduce the inactive pulses and improves the stability of process. Also US-EDM is effective in attaining a high material removal rate (MRR) in finishing regime in comparison with conventional EDM. The results of Analysis of Variance (ANOVA) indicate that the proposed mathematical models can adequately explain the performance within the limits of the factors being studied.