Comparative assessment of surface roughness produced by hard machining with mixed ceramic tools including 2D and 3D analysis

This paper provides a new comprehensive analysis of part surface finish in continuous dry turning of a hardened construction steel when using mixed alumina cutting tools. Consequently, the surface profiles (2D arragement) and surface microstereometries (3D arragement) generated during different hard part turning operations on a 40H low chromium alloy steel (equivalent to AISI 5140 or DIN 41Cr4), heat treated to the hardness of about 60 HRC, were evaluated. As a result, this paper aggregates the multi-parameters characterization of the surface roughness with the machined surface structure obtained at the three selected feed rates and constant cutting speed of 100 m/min. Results show that hard turning with mixed alumina tools produces specific surface profiles and microstructures, although the Ra roughness values of about 0.25 μm can be comparable to those produced by finish grinding.