Comparative study of rotary-EDM, gas assisted-EDM, and gas assisted powder mixed-EDM of the hybrid metal matrix composite

Abstract

ABSTRACT Hybrid metal matrix composite is an integration of two or more reinforcements to produce better strength, stiffness, and high strength to weight ratio. However, low material removal and high electrode wear are some of the major obstacles in the EDM processing of hybrid metal matrix composites due to the fragile and non-conductive nature of the reinforcement ceramics. For this purpose, processes such as rotary electrical discharge machining (REDM), gas-assisted electrical discharge machining (GAEDM), and gas-assisted powder mixed electrical discharge machining (GAPMEDM) are compared on the basis of the material removal rate and the electrode wear rate. The metal removal rate obtained in the gas-assisted powder mixed electrical discharge machining process is up to 75% higher and the electrode wear rate is at least 25% lower than the REDM process. The metal removal rate acquired by the gas-assisted powder mixed electrical discharge machining process is at least 45% better and the electrode wear rate is at least 15% lower than the GAEDM process. Experimental findings show that MRR is better and EWR is lower in GAPMEDM compared to GAEDM and the conventional REDM process.