An Investigation on Machinability of Al/10 % ZrO2(P)-Metal Matrix Composite by WEDM and Parametric Optimization Using Desirability Function Approach

Abstract

This paper presents an experimental investigation of the machining characteristics and the effect of wire electrical discharge machine process parameters during machining of newly developed Al/10 % ZrO2(p) metal matrix composite (MMC). The MMC is fabricated by liquid-melt stir casting process and then solution heat treated (T6). The hardness and tensile strength of the solution heat-treated samples are 138.7 BHN and 472.66 MPa, respectively. Central composite design of response surface methodology (RSM) is used to design the experiment and is performed to investigate the effects of process parameters such as pulse width, time between pulses, servo control mean reference voltage, short pulse time, wire feed rate and wire mechanical tension on performance measures such as surface roughness and cutting velocity (CV). Mathematical models are developed to predict the results for performance characteristics well in advance. Desirability function approach is used to find the optimal parametric combination for single-objective optimization as well as for multi-objective optimization. The CV 8.1235 mm/min. and surface roughness 1.2549 μm indicate that the developed MMC can be successfully machined by wire EDM. Additivity test and confirmation test are performed to validate the mathematical model and to confirm the optimal parametric combinations developed by RSM, respectively. Mechanical properties investigation and successful machining indicate that this material can be used in the aerospace industries.