Experimental investigation of wire-edm machining of low conductive al-sic-tic metal matrix composite

Abstract

The application of metal matrix composites (Al-SiC-TiC) in aerospace and defense industries have surged in the areas of hull safety, aviation fins, and closure units. The close to ideal solution for generating powdered mixture availing ball milling, for processing of a metal matrix composite of size 24 × 24 × 5.95 cm3 and composition of 75% Al, 10% SiC, and 10% TiC weight composition is 10:1 ball weight ratio, ball size of 8 mm, rotation speed of 250 rpm, and milling time of 4 h. The powdered mixture is compressed to pellet, sintered for two hours, and further silver coated in a physical vapor deposition setup to surge its electrical conductivity for ease of material removal. To obtain a perfect fit and finish, wire electrical discharge machining cycle has been carried out to machine the component under deionized water and oil + wax + paraffin dielectric mediums in 8 A peak current, 0.45 µs pulse on time, and 45 pulse off time as close to ideal solution, obtained by the technique for the order of preference by similarity to the ideal solution (TOPSIS) analysis. A surge is ascertained in kerf width, material removal rate, and surface roughness in oil + wax + paraffin environment in correlation with deionized water by 0.99–12.78%, 0.18–33.97%, and 2.15–36.86% respectively. The surface morphological study indicates a 32.28%, 42.57%, and 45.73% surge in residual compressive stress, surface roughness and corrosion resistance in oil + wax + paraffin dielectric medium in correlation to deionized water.