Improvement of tool life via unique surface modification of a tungsten carbide tool using a large pulsed electron beam in Ti-6Al-4V machining

The surface quality of a cutting tool is an important factor for determining machinability performance. This paper proposes a new approach to improve the tool surface quality using large pulsed electron beam (LPEB) irradiation. LPEB irradiation is a process that enhances the mechanical characteristics of substrate surfaces. In this study, the effects of LPEB irradiation on a tungsten carbide tool were evaluated over the acceleration voltage range of 10 to 40 keV. Surface modification of the cutting tool was analyzed in terms of the tool's material constituents, mechanical properties, edge roundness, and surface roughness. LPEB irradiation at 30 keV modified the cobalt and carbon contents of the tool surface, thus improving hardness, compressive strength, and tool surface roughness. The machinability of the LPEB-treated cutting tool was investigated based on the tool wear by performing an orthogonal cutting experiment of Ti-6Al-4V. After treatment with 30 keV LPEB irradiation, the tool wear was reduced; specifically, the flank wear length was reduced by up to 64.6 %, compared to the untreated cutting tool. An examination of the 30 keV irradiated machined material surface and the chip morphology showed substantial reductions in the surface roughness and friction coefficient, by 56.5 % and 31.2 %, respectively, compared with the untreated condition.