Experimental investigation on surface integrity of end milling nickel based alloy-Inconel 718

Inconel 718 is a typical difficult-to-machine material, and its high speed end milling process has wide applications in manufacturing parts for aerospace and power industry. Surface integrity of these parts greatly influences the final characteristics. This paper presents an experimental investigation to evaluate surface integrity behaviors of Inconel 718 with finishing cutting parameters in terms of surface topography, surface roughness Ra, residual stresses and subsurface microstructure and microhardness. The results show that high cutting speed is advisable to get better surface topography and roughness. Residual stresses and subsurface microhardness barely increase after 80m/min. Microstructure in surface layer has only slight deformation after high speed milling.