Non-conventional machining of nickel based superalloys: A review

Abstract

Nickel, the 24th most abundant element, is found in 0.016 % of the earth's crust. Addition of Nickel is used as an alloying element in hardenable steels, stainless steels, high-temperature alloys,corrosion-resistant and“nickel-silver,” and aluminium-nickel alloys. Nickel improves the toughness and ductility of cast iron. Nickel-base super alloys (Inconel) are widely regarded as one of the most difficult materials to machine because of their extreme hardness, high strength at high temperatures, tendencyto react with tool materials, and low thermal diffusivity. Because of various issues that arise during the machining process, nickel-based superalloys are regarded as difficult to machine materials; heat will advance into the tool material, causing tool wear tear and premature tool failure. To overcome these challenges, a non-conventional machine process is beneficial for super alloy machining. The present study is review of various nickel-based super alloys and their types, introduction to the non-conventional machining techniques applied to superalloys over the past few decades. Machining with non-conventional methods concludes with some key findings and gaps regarding nickel-based superalloys.