Performance evaluation of dielectric fluids in micro electrical discharge milling of Ti 6al 4v alloy

Abstract

newline Micromachining of micro features in metals by conventional machining processes is difficult. Metallic micro channels are primarily used in applications related to heat transfer and fluidic controls. Fabrication of micro channels with high aspect ratio is a tough task while applying the conventional machining process due to issues such as tool breakage and burr formation. Many non-contact machining techniques are available for the generation of micro channels; among these techniques micro Electrical Discharge Machining (EDM) is a simple and reliable technique to produce micro channels. Hydrocarbon based dielectric oils Micro Electric discharge milling (and#956;ED milling) is a variant of micro EDM which has the potential to create micro channels in metals irrespective of its mechanical properties. Since Micro ED milling is a slow machining process, the requirements of strategies that can enhance the material removal rate (MRR) are always crucial in the field of micro-machining. have proved their superiority as oil for EDM process in terms of performance characteristics but serious health issues such as skin cancer, respiratory problems and lung cancer are predominant among the operators. An experimental investigation was conducted to study the feasibility of the biodiesel oil as a dielectric fluid during micro ED milling of titanium alloy (Ti-6Al-4V) with cryogenic treated tool under three different discharge energy regimes. The behaviour of biodiesel was seen as the same as EDM oil, but the EDM oil gave a high material removal rate and low surface roughness compared to biodiesel. Coconut biodiesel was in close proximity range with EDM oil than jatropha and karanja biodiesels. The breakdown voltage was seen as higher in the case of biodiesel fluids. Crater diameter increased by 6%, 22% and 31% respectively with coconut, jatropha and karanja biodiesel fluids than EDM oil due to high spark density. Experimental results revealed that the biodiesel could be a real alternative to hydro carbon based oil for Micro ED millin