Cutting condition effects on microstructure and mechanical characteristics of Ni-based superalloys—a review

Surface integrity is considered to be a significant factor in evaluating surface qualities. A wide range of applications of nickel-based superalloys can be attributed to a number of features such as mechanical and chemical characteristics at elevated temperatures, high durability and ductileness, great resistance to corrosion, high melting point, thermal shock, thermal fatigue, and erosion. However, the practical performance of the component particularly the fatigue life is critically influenced by the machined surface finish of Ni-based superalloys. The present review article provides the most recent information on various surface integrity properties while machining Ni-based superalloys. The surface integrity aspects contain the surface topography including machined surface defects (plucking, metal debris, feed marks, surface cavities, smeared material, grooves and laps, cracking, carbide particles, and redeposited materials) and surface roughness; the metallurgical phase consists of plasticity, grain refinement and orientation, and white layer formation, and mechanical characteristics comprise the residual stress and strain hardening. The impact of various cutting parameters, the cutting environment, and cutting tool materials have been carefully explained on surface metallurgy and mechanical characteristics. Moreover, the influence of surface integrity on the fatigue life of machined components has been studied.