EDM of Ti6Al4V under nano-graphene mixed dielectric: a detailed roughness analysis

Abstract

Surface finish has an essential role in superior performance of machined products which becomes crucial for sophisticated applications like invasive biomedical implants and aerospace components. Ti6Al4V is popular in these applications due to its exceptional characteristics of weight-to-strength ratio. However, Ti6Al4V is a difficult-to-cut material; therefore, non-traditional cutting techniques especially, electric discharge machining (EDM), are widely adopted for Ti6Al4V cutting. The engagement of nano-powders are used to upsurge the cutting rate and surface quality. Among the different powders, a novel nano-powder additive, i.e., graphene, has not been tested in EDM of Ti6Al4V. Therefore, the potential of nano-graphene is comprehensively investigated herein for roughness perspective in EDM of Ti-alloy. The experimental design is based on Taguchi L18 orthogonal framework which includes six EDM parameters. The experimental findings are thoroughly discussed with statistical tests and physical evidence. The surface quality achieved with an aluminum electrode was found best amongst its competitors, whereas the worst surface asperities were noticed when brass electrode was used under graphene mixed dielectric. Moreover, it is conceived that the positive tool polarity provides lower roughness for all types of electrodes. Furthermore, optimal settings have been developed that warrant a reduction of 61.4% in the machined specimen’s roughness compared to the average roughness value recorded during the experimentation.