ORIGINAL ARTICLE Assessment of operational feasibility of waste vegetable oil based bio-dielectric fluid for sustainable electric discharge machining (EDM) Janak B. Valaki 1,2 & Pravin P. Rathod 3 Received: 26 November 2014 /Accepted: 19 April 2015 # Springer-Verlag London 2015 Abstract Since the first application of electric sparks for the material removal was demonstrated, the electric discharge ma- chining (EDM) process has gone through considerable chang- es in terms of technology and application. The process has surpassed the technological barriers by overcoming its then thought limitations like processing speed, material conductiv- ity, dimensional and geometrical accuracies, and surface fin- ish. However, environmental impact due to release of toxic emission products, operator health concerns due to release of toxic fumes, vapours and aerosols during the process, poor operational safety due to fire hazards and electromagnetic ra- diation, and toxic and non-biodegradable dielectric waste gen- erated are some of the concerns still prevailing in EDM pro- cess. Authors, in this paper, have assessed the operational feasibility of waste vegetable oil (WVO) as possible alterna- tive dielectric fluid and compared the response patterns of WVO with hydrocarbon oil, kerosene. Experiments were per- formed using spark current, gap voltage, pulse on time (pulse duration) and pulse off time (pulse interval) as control param- eters to study the response behaviour for material removal rate (MRR), electrode wear rate (EWR) and tool wear ratio (TWR). The results obtained reveal that WVO-based bio-di- electric fluid can be used as an alternate to hydrocarbon-, water- and synthetic-based dielectric fluids for EDM. Besides the successful trials for operational feasibility assessment, ap- plication of bio-fluids offers a cleaner, greener and safer solu- tion for dielectric to improve sustainability of EDM process by improving environmental friendliness, operational safety and personnel health issues of the process. Based on the ex- perimental results and observations, the authors have sug- gested further scope of works to improve sustainability of the EDM process. Keywords Sustainability . Sustainablemanufacturing . Waste vegetable oil (WVO) . Bio-dielectric fluid . Hydrocarbon dielectric . Operational feasibility . Sustainable EDM Abbreviations EDM Electric discharge machining WVO Waste vegetable oil MRR Material removal rate (mm 3 /min) EWR Electrode wear rate (mm 3 /min) TWR Tool wear ratio(%) BHN Brinell hardness number T on Pulse on time (μs) T off Pulse off time (μs) 1 Introduction to EDM technology Electric discharge machining (EDM) is one of the most prac- ticing and versatile non-conventional metal removal process with more than 7 % market share amongst all manufacturing processes [1]. Because of its ability for hybridisation with other conventional and non-conventional processes, EDM variants like die sinking, wire cut EDM, electric discharge drilling [2], electro-discharge milling [3], electro-discharge grinding [4, 5], electric discharge coating [6], electric * Janak B. Valaki janakvalaki@gmail.com 1 Research Scholar, School of Engineering, RK University, Rajkot 360020, Gujarat, India 2 Mechanical Engineering Department, Government Engineering College, Bhavnagar 364001, Gujarat, India 3 Mechanical Engineering Department, Government Engineering College, Bhuj, Kuttchh 370001, Gujarat, India Int J Adv Manuf Technol DOI 10.1007/s00170-015-7169-0