Effect of cutting edge radius when milling hardened steels: a finite element analysis and surface integrity investigation

Abstract This work investigated the impact of cutting tools varying edge radii by presenting a 3-dimensional finite element analysis (3D FEA) model during the milling of hardened steels. The proposed numerical model was able to capture the effect of micro geometrical changes between cutting tools of five different edge radii (25 30 35 40 and 45 ). Experimental milling tests were performed to validate the numerical model and close agreement was reported between the experimentally acquired cutting forces and the numerically simulated ones. Results concluded that experimental and numerical cutting forces increased with the increase of edge radius. Furthermore, the effect of the five different edge radii and cutting conditions on the integrity of machined surfaces were studied. The integrity parameters of choice were surface roughness, feed marks pattern, subsurface plastic deformation, and subsurface microhardness. Results indicated that the surface roughness increased with increasing the feed rate and decreasing the cutting speed, and vice versa. However, altering the edge radius did not introduce a significant impact on the surface roughness. Results also revealed that increasing the edge radius made feed marks more visible and increased the subsurface plastic deformation and microhardness beneath the machined surface.