Wire electrical discharge machining of AA7075/SiC/Al2O3 hybrid composite fabricated by inert gas-assisted electromagnetic stir-casting process

Abstract

This paper investigated the effect of wire electrical discharge machining process parameters like discharge duration, pulse interval time, discharge current and the wire drum speed on the kerf width while machining newly developed hybrid metal matrix composite (Al7075/7.5 % SiC/7.5 % Al2O3). The hybrid composite was prepared by inert gas assisted electromagnetic stir-casting process. Taguchi method was used for parameter optimization and the level of importance was determined using analysis of variance. The results show that discharge duration, discharge current and wire drum speed were significant parameters. The discharge current was the most significant parameter that contributed maximum (47.16 %) to the kerf width followed by discharge duration (38.36 %), wire drum speed (5.16 %), and interaction, discharge duration × discharge peak current (5.47 %). The pulse interval time had insignificant effect on the kerf width. In confirmation test, the average experimental value of kerf width (228.7 μm) was within an error of 2.56 % of the predicted value at the optimum level of process parameters.