Investigation on material removal rate and surface roughness in electrical discharge turning process of Al 7075-based metal matrix composites

Abstract

An attempt is made for the first time to machine metal matrix composites (MMCs) consisting of aluminium alloy 7075 (Al7075) reinforced with silicon carbide (SiC) in the form of particles with different particle sizes such as 0.149 mm and 0.018 mm using wire electrical discharge turning (WEDT) process. The experiments were conducted based on response surface methodology (RSM) using Box-Behnken method. The input machining parameters considered are pulse-on time (TON), pulse-off time (TOFF), gap voltage (V) and spindle speed (SS). The significant WEDT parameters and their levels were identified for higher material removal rate (MRR) and lower surface roughness (Ra) by using response surfaces. From this study, it is found that similar combinations of WEDT process parameters resulted in higher MRR in both the materials studied in this work. However, in the case of Ra, it is found that the different combinations of process parameters and their levels are significant. The findings from this study are useful to manufacturing engineers in order to increase productivity during cylindrical turning of Al/SiCp-based MMC in WEDT process.