Experimental investigation to assess the surface integrity in WEDM of Al-based hybrid composite material

Abstract

Aluminum-based hybrid composites are used in various engineering applications due to their unique properties, such as high strength, good wear resistance, excellent corrosion resistance, and low density. Aluminum metal matrix (AMMC) composites reinforced with ceramic particles can be more difficult to machine than traditional aluminum alloys because of their increased hardness and abrasiveness. Wire electric discharge machining is a non-traditional machining process that uses a thin metal wire, typically made of molybdenum, brass or tungsten to cut through a workpiece using electrical discharge sparks. This process is useful for precision machining of complex shapes and profiles in hard or difficult to machine materials. WEDM is a commonly used process for cutting Al-SiC-ZrO₂ HAMMCs due to their hardness and difficulty in machining using conventional techniques. The present study examines the relationship between machining parameters like pulse on time (T_ON), pulse off time (T_OFF), peak current (I_P) and wire feed (WF) and material removal rate (MRR) and surface roughness (R_a) for Al-SiC-ZrO₂ in WEDM. The Box-Beckham Design was used to plan the experiments, and response surface method was employed to develop the models. The pulse duration, T_OFF, I_P, and quadratic terms of $T_{OFF}^2$ and $I_P^2$ are the most influential factors of the MRR. The T_ON, I_P and interaction term (T_ON× I_P), and $I_P^2$ were the most significant factors for R_a. Multi-response optimization of process parameters was obtained using the desirability function approach. Furthermore, the machined samples were analyzed for surface integrity using SEM techniques. The prediction from this model validated the confirmation results.