EXPERIMENTAL RESEARCH OF PARAMETRIC OPTIMIZATION ON WIRE ELECTRICAL DISCHARGE MACHINING OF AA7075/ZRB₂ IN SITU COMPOSITES

Abstract

The AA7075 composites reinforced with 3, 6, and 9 volume fractions (vol.%) of ZrB2 particles have been successfully fabricated using in situ fabrication method. In this technique, the inorganic salts K2ZrF6 and KBF4 were added to the molten aluminum and retained the melting at 900∘C to form the required vol.% of ZrB2 particles. The aluminum-reinforced metal matrix composites (MMCs) are commonly known as aluminum matrix composites (AMCs). This work carries the effects of various wire electrical discharge machining (WEDM) input process parameters like pulse-on-time ([Formula: see text]), pulse-off-time ([Formula: see text]), wire feed rate (WFR), and gap voltage (GV) on the output responses such as material removal rate (MRR), surface roughness (SR), and Kerf-width ([Formula: see text]) of the fabricated AA7075/(3, 6, and 9) vol.% ZrB2 in situ AMCs. Based on Taguchi’s L9 orthogonal array method, the design of experiments (DoE) was used to carry out the operations on the fabricated AMCs. The optimal level of process parameters was found by the main effects plot for signal-to-noise (S/N) ratio, contour plots, and the analysis of variance (ANOVA). The effect of these process parameters on MRR and SR was analyzed and it is found that the maximum MRR was attained in the optimal parametric combination of GV [Formula: see text][Formula: see text]V; [Formula: see text][Formula: see text][Formula: see text]s; [Formula: see text][Formula: see text][Formula: see text]s; WFR [Formula: see text][Formula: see text]mm/s; Reinforcement [Formula: see text] vol.%, and the minimum SR was attained in the optimal parametric combination of GV [Formula: see text][Formula: see text]V; [Formula: see text][Formula: see text][Formula: see text]s; [Formula: see text][Formula: see text][Formula: see text]s; WFR [Formula: see text][Formula: see text]mm/s; Reinforcement [Formula: see text] vol.%.