Investigations on electric discharge machining of copper-Al<sub align="right">2O<sub align="right">3-Gr powder metallurgy composites

Copper composites with five weight percentage of alumina and graphite weight percentage of 0, 2.5 and 5 were produced by powder metallurgy process. To examine the presence and distribution of reinforcements in the produced copper composites, metallurgical characterisation such as X-ray diffraction analysis and scanning electron microscopic analysis was performed. Further to analyse the machining behaviour of the produced composites, electrical discharge machining was performed using Taguchi's L27 orthogonal design by considering pulse on time, pulse off time and current as the machining parameters. To ascertain the behaviour of electric discharge machining of produced composites, statistical analysis was performed and the optimal levels of parameters was obtained through the main effect plot. Through the response table and ANOVA analysis, the significant factors were identified and finally, the test results were validated with a confirmation test.