Machined surface roughness and chip morphology in high speed side milling of inconel 718

Nickel-based Superalloy Inconel 718 is a difficult-to-machine material wide used in hot sections of gas turbine engines in aerospace industry. In this study, machined surface roughness of the machined surface in high speed side milling of Inconel 718 using a solid carbide end mill was investigated experimentally for a wide range of cutting conditions, and chip morphology during dry milling of Inconel 718 has been examined under different cutting speeds using scanning electron microscope (SEM). The experimental results have shown that the milled surface shows good surface quality with the range of surface roughness values in the feed directions from 0.05 to 0.3μm. Surface roughness value decreases with the increase of cutting speed in the range of 40-100 m/min, but has much less variation in the feed and depth-of-cut (DoC) range. In addition, the degree of chip serration increased with the increase in cutting speed.