A review on sustainability, health, and safety issues of electrical discharge machining

摘要

Electrical discharge machining (EDM) is a well-practiced non-traditional machining process in the manufacturing, aerospace, and biomedical instrumentation industry, used to machine hard metals, alloys, composites, and ceramics. But EDM has some demerits such as low material removal rate (MRR), high power consumption, and dependency on conventional fluids (kerosene and hydrocarbon oil as dielectric), which lowers its sustainability index. Besides these, toxic fumes, vapors, and aerosols are released during the process. Generation of toxic and non-biodegradable dielectric waste and its disposal is also a severe problem. The toxic gases adversely affect the environment and human beings. The risk of fire and health hazards to the operator is also a cause of concern. The present article deeply emphasizes the issue of the emergence of toxic fumes during machining and the use of some alternative dielectric mediums, which are the justified and potential substitutes of conventional EDM oils. This review article mainly focuses on the machining performance of different green EDM techniques, the environmental impact of EDM, and personnel health and operational safety. Various types of diseases caused by toxic gases are also reviewed. This review article is based on 299 articles published from 1981 to 2021. A detailed discussion on water-based dielectrics, powder-mixed EDM, vegetable oil-based EDM, dry and near-dry EDM is presented in the paper. Finally, the article winds up with research gaps and future scope and concluding remarks.