Parametric Optimization of Thermoelectric Machining of Stir-Cast Hybrid Magnesium Metal Matrix Composite with Alumina and Silicon Carbide as Reinforcement

Magnesium alloy and composites have its applicability in aerospace industry due to exceptional properties yet being lighter. Their biodegradable property makes it useful in orthopedic implants as well. In this paper, a novel Al₂O₃ (2% wt)- and SiC (4% wt)-reinforced hybrid magnesium metal matrix composite (MMMC) has been developed using stir casting. The developed samples of MMMC are machined using the thermoelectric machining (CNC wire-cut EDM) process. RSM-BBD approach was used to develop experimental models for material removal rate (MRR) and surface roughness. The effect of EDM parameters on output responses has been recorded, and similar variation is observed with response surface plots. It is found that wire speed is most significant parameter for MRR and highest value of MRR is obtained as 0.159 mm³/sec. Pulse-on time is most significant parameter for surface roughness followed by current. Lower values of input parameters are more significant in obtaining better surface quality. Lowest value of surface roughness is obtained as 3.932 microns. Input parameters are optimized using composite desirability approach of RSM for metal removal rate and surface roughness.