A Review on Electro-Discharge Machining on Aluminium Metal Matrix Composites

Abstract

Present manufacturing industries are facing challenges from these advanced materials viz. composites, ceramics and super alloys, that are hard and difficult to machine, requiring high precision, surface quality which increases machining cost. To meet these challenges, non-conventional machining processes are being employed to achieve higher metal removal rate, better surface finish and greater dimensional accuracy, with less tool wear. Electrical Discharge Machining (EDM) is the process of machining electrically conductive materials by using precisely controlled sparks that occur between an electrode and the work piece in the presence of a dielectric fluid. Aluminium Metal Matrix Composites (AMMCs) are new generation engineering materials that possess superior physical and mechanical properties compared to non-reinforced alloys. This makes them attractive for wider range of applications in automotive, aerospace and defense industries. These materials have desirable qualities such as high strength to weight ratio, high toughness and low value of coefficient of thermal stability. It is very difficult to cut the complex shapes by using Conventional Machining. High tool wear and high cost of tooling is also a limitation in Conventional Machining, Unconventional Machining offers an alternative solution to this problem. This paper presents a review of research work done on AMMCs on EDM, Wire EDM, Powder Mixed EDM, EDM in Water, Micro EDM. The paper also discusses the future trends of research work in the same area.

Keywords: Electrical Discharge Machining, Metal Matrix Composites, Pulse ON Time, Pulse OFF Time, Metal Removal Rate, Tool Wear

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