Experimental investigation of abrasive assisted hybrid EDM of Ti-6Al-4V

Abstract

Hybrid electric discharge machining (EDM) has been a promising technique for improving overall machining efficiency for hard-to-cut material. This, to some extent, has been related to the conventional EDM being incompetent for mass production owing to low material removal and reduced surface quality. Hence, the powder mixed electrical discharge machining (PMEDM) hybridized with abrasive jet machining (AJM) has been carried out. The tool wear rate (TWR), material removal rate (MRR) and surface finish study of titanium (Ti-6Al-4V) have been investigated. This hybrid EDM has been performed with and without abrasive jet flushing for evaluation of various eminent responses, namely MRR, TWR and SR, taking into account the input process parameters. Copper electrodes with variable inner hole diameter were used for machining of workpiece in SiCp mixed dielectric fluid. The experiments were planned and analyzed using Taguchi approach. This machining route revealed an appreciable enhancement in MRR when coupled with abrasive jet flushing and enhanced surface finish at the same time. The tool wear was significantly affected by peak current and use of SiC particulates in dielectric. In abrasive mixed flushing technique, an increase in tool erosion was spotted. Moreover, hole size, pulse-off and abrasive mixed dielectric proved to be influential in declining the surface finish of the finished component. The SEM analysis of Ti-6Al-4V samples put forward that pulse-on duration, current and type of dielectric fluid exhibited a vital influence on the topology and microstructure of machined surfaced along with their interactions.