Optimization of electric discharge machining parameters for AL-3 weight % nano SiCp composites using copper electrode

Aluminium matrix composites have seen the most wide spread applications and it is the most emerging material in the automotive, aircraft, defence and other applications. Silicon carbide particles have a high modulus of elasticity, higher hardness, low coefficient of thermal expansion and density which when reinforced with Al-alloys make them highly attractive materials. These composite materials offer improved properties such as high strength to weight ratio, high stiffness, corrosion resistance, low coefficient of thermal expansion and closer dimensional tolerance. The complexity and degree of precision required for components in industries need holes to be straight, accurate and exactly positioned that is possible by non traditional machining like electric discharge machining.

In the present study the effect of machining responses MRR, and TWR on the Al-3 wt. % Nano SiC Composite plate fabricated through ultrasonic assisted stir casting process. The experiments were conducted on ELECTRONICA smart S 50 CNC EDM using copper electrode of 15.1 mm diameter with side flushing. The experiments were performed under various parameters setting of Pulse on Time (Ton), Peak Current (Ip) and Servo voltage (V). L27 full factorial design, three factor-three level setup was used in the experiment. Minitab software was used for analysis and formulation of linear mathematical regression equations. The objective functions were optimized in MATLAB using Genetic Algorithm with terminating current iteration 51. The input parameters Ton, Ip and V were varied from 200 to 400 micro second, 20 to 40 amperes and 70 to 90 Volt respectively. Maximum value of MRR was obtained at Ton (396.413μs), Ip (39.999 A) and V (84.76 V). Minimum value of TWR was obtained at Ton (344.71μs), Ip (39.994 A), and V (70.005 V).