Influence of edge hone radius on cutting forces, surface integrity, and surface oxidation in hard milling of AISI H13 steel

Tool edge preparation has a remarkable influence on tool wear behavior and therefore on the machining performance. In this present research, hard milling of AISI H13 steel (50 +/- 1HRC) with uncoated carbide tools was experimentally conducted to identify the effect of an edge hone radius on cutting force, surface integrity (surface roughness, hardness, microstructural changes, and residual stress), and surface oxidation. Experimental results are evaluated by means of an optical profilometer, Nano Tester, optical microscope, SEM, XRD, X-ray stress measurement, and EDS. First, the effect of edge hone radius on cutting forces and surface integrity is significant. That is the cutting and feed forces increase with the increase of edge hone radius, and the lower surface roughness is obtained when using a cutting tool with edge hone radius of 30 mu m. Secondly, the nano-hardness in the machined surface, depth of plastic deformation, and compressive residual stress increase with the increase of edge hone radius. Thirdly, neither a white layer nor phase transformation occurs in the machined surface during hard milling process. Finally, no oxygen enrichment and carbon concentration is observed in the subsurface. This research is benefitted to providing a guide to optimize the edge hone radius and acquires a desirable machining performance.