An Experimental Investigation of Process Optimization of EDM for Newly Developed Aluminium Metal Matrix Composites

The aim of this investigation is to investigate the contribution of controllable input parameters (viz. pulse on times, peak currents) on the performance of two newly developed MMCs (Al-8.5%SiC-1.5%Mo and Al-7%SiC-3%Mo). Both the metal matrix composites were fabricated using the stir-casting method. Thereafter, various tests such as microhardness test, tensile test, and porosity analysis of the newly developed composite were performed. To carry out the machining trials, an L18 orthogonal array (OA) was chosen. Optimization of the machining process was performed according to Taguchi analysis followed by grey relational analysis (GRA). The results showed that with increasing weight fraction of the molybdenum particulates, microhardness and density of the composites increase with a small reduction in the tensile strength. In addition, pulse on time is the most contributing parameter among others to obtain optimal process performance. The optimum setting of input variables suggested by GRA to obtain optimal responses is a molybdenum composition of 3%, Pulse on time of 70 µs, and a peak current of 9A. Based on the interaction plot, it is evident that process performance measures of EDM depend on controllable input parameters.

Keywords: AMMC, EDM, GRA, Molybdenum, Optimization, Silicon Carbide.