Machining of difficult-to-cut Super alloys: A Review

Abstract

Excellent physical, mechanical and chemical properties at high temperatures, toughness and ductility, high
resistance to corrosion, resistance to thermal distortion are making super alloys favorable in the industries. They are on
high demand in the chemical, marine, and aerospace industries. Improvements are suggested in the area of machining of
difficult to cut materials having poor machinability due to low thermal conductivity, to maintain high strength at elevated
temperature and chemical reaction. The most affecting factors which governs the machinability of Super alloys are
machined surface of work material and tool life. A Proper selection of cutting tool materials, cutting parameters and
conditions, as well as the functional behavior of machined specimen gives efficient machining of super alloys. This paper
presents an overview of advancement in the machining techniques which can improve the productivity along with cost
reduction without compromising dimensional and geometrical accuracy, machined surface quality in terms of roughness,
finish, subsurface quality and hardness. Various cutting parameters, cutting environment and tool geometry on different
features of machined surface quality has been presented. These includes surface roughness, surface defects in the form of
cavities, metal debris, smeared material, feed marks etc., metallurgical and microstructural aspects.