Investigation of WEDM process parameters of Al–SiC–B4C composites using response surface methodology

Abstract

Aluminum based composites are widely used in various engineering applications. Though the processing of these materials is easy, it requires advanced machining techniques to cut the same as it becomes harder after the addition of ceramic reinforcements. The wire electrical discharge machining (WEDM) process is employed for cutting of Al–SiC–B4C hybrid metal matrix composites with the varying machining conditions. The machining factors, namely current (12A–20A), pulse on time (100μs–120 μs), the wire feed rate (6 mm/min – 10 mm/min) and the content of B4C (weight percentage) in the composite are considered for the performance evaluation. A response surface methodology (RSM), the multi-objective optimization technique is adopted for determining the influence of parameters on the machining features like kerf width and cutting speed. The experimental analysis revealed the correlation between the input and output characteristics. The minimum kerf width of 0.271 mm is attained at a wire feed rate of 10 mm/min and current of 12 A. The maximum cutting speed of 4.76 mm/min is achieved at a pulse on time of 110 μs and a wire feed rate of 8 mm/min. The optimum machining condition obtained through RSM method is current of 20 A, pulse on time of 108.6 μs, wire feed rate of 10 mm/min and 5.65% of the B4C content in the composites. Keywords: Aluminum composites, Stir casting, WEDM, Response surface methodology