EFFECT OF WIRE ELECTRODE MATERIALS ON PERFORMANCE CHARACTERISTICS FOR WIRE ELECTRICAL DISCHARGE MACHINING OF METAL MATRIX COMPOSITE MATERIAL

Composite materials are the advanced materials which are widely used in manufacturing industries. The most commonly used composite materials are metal matrix composites. Due to the presence of abrasive reinforcing particles, traditional machining of these causes severe tool wear and hence reduces the life of cutting tool. Wire electrical discharge machining (WEDM) is quite successful for machining of metal matrix composites. Wire Electrical Discharge machining is a specialized thermal machining process capable of accurately machining parts of hard materials with complex shapes. One of the main research fields in WEDM is related to the improvement of the process productivity by avoiding wire breakage. Wire electrodes used in WEDM are the core of the system. In this study the effect of different wire electrode materials on electrode wear and surface finish for wire electrical discharge machining of metal matrix composite material were investigated. The experiments were conducted under the following process parameters viz., pulse-on time, pulse-off time, wire feed speed and current. For the experiment the aluminium 6061 alloy with 0%, 5%, and 10 % of silicon carbide (SiC) reinforcement material was used. To conduct the experiment CNC wire EDM machine with two different wires viz., molybdenum and brass wire was used. Experimental results indicate that for better surface finish of Al6061 alloy, the brass wire is more suitable. The use of brass wire as electrode material leads to significant reduction in electrode wear in machining of Al-5%SiC and Al-10%SiC composite materials compare to molybdenum wire. Increasing percentage of silicon carbide in aluminium 6061 alloy increases the variation in surface finish and electrode wear. Wire wear rate of both brass and molybdenum wire is increased with increase in percentage of silicon carbide.