Improvement of Optimal Process Parameters in EDM of Aluminium Based Alloy and Composite Materials Using RSM

Advanced trade materials such as polymers, ceramics, composites, and super alloys play an ever increasing important role in modern manufacturing industries. There are many applications, where engineers have reached the performance limit of metals, and there is no alternative but to seek the use of advanced material in various applications like aluminum alloy and composite. Machining of aluminum alloy and composite requires the need for better understanding of cutting processes regarding Material Removal Rate (MRR) and Surface Roughness (Ra). To meet the challenges of the changing world, the Electrical Discharge Machining (EDM) process must have the process capability, accuracy and robustness. In EDM process, it is important to select machining parameters for achieving optimal machining performance in these types of materials. To achieve this goal, the EDM process has to be modeled and optimized. In this work, Response Surface Methodology is used to investigate the effect of six controllable input variables namely peak current, discharge voltage, pulse on time, pulse off time, spark gap and oil pressure and also two output variables like MRR and SR are the responses. The experimental work is to know the effect of above-mentioned six input variables on EDM and to conclude this effect on the MRR and SR. This paper describes optimizations of EDM processes using RSM giving the details of formulation of optimization models, solution methodology used and optimization result in machining of Al alloy with HE9 and LM25 Al/10% SiC.