Experimental investigation of powder mixed electrical discharge machining of LM-25/SiC composites: A response surface methodology coupled with desirability approach

In the last few years, many experiments have been done on lightweight Al and SiCp MMCs for aerospace and automotive applications. The results have been consistent in the development of structural and super alloys. Present work explores the performance characteristics of powder mix EDM by machining Al, LM-25 alloy with various weight fractions of reinforcement (0%, 5%, and 10% SiC) and variable electrode material. The impact of heat treatment on the microstructure of Al LM-25/10%SiC MMC has also been examined. Experimental investigation has been conducted to examine the machine response by adjusting the process parameters by employing the statistical design of RSM. The machining characteristics have been estimated to assess the machine response, namely metal removal rate (MRR) and tool wear rate (TWR), which are closely related to process variables, discharge current (I p), pulse on time (Ton), servo voltage (V), different tool materials, varying work materials, and differing concentrations of abrasive particles. The ANOVA results show that tool material is the most crucial parameter for MRR, accounting for 11.90% of the total, followed by other process variables, and the pulse on time for TWR, accounting for 5.94% of the total. Scanning Electron Microscope (SEM) was used to examine the macrostructure of machined MMCs. A chemical microanalysis technique such as Energy Dispersive Spectroscopy (EDS) and X-ray diffraction (XRD) was used to determine the phase composition of the materials and material dispersion. Additionally, the desirability technique was used to identify the optimum machining conditions.