Effect of cryogenic grinding on surface characteristics of additively manufactured Ti-6Al-4V alloy

Abstract

Abstract Additive manufacturing has the potential to develop three-dimensional customized components directly in a layered fashion. One of the major challenges is the surface roughness of components fabricated by this process. An experimental investigation into the effect of cryogenic grinding on the surface characteristics of direct metal laser sintered (DMLS) Ti-6Al-4V alloy has been performed. Before experimentation, the DMLS Ti-6Al-4V components were heat-treated at 800 °C for 1.5 h to relieve the residual stresses generated during fabrication. The surface morphology, microhardness, and surface roughness were measured and evaluated. The results show that there were significant effects of different grinding characteristics and environments on the grinding forces, temperature, surface roughness, force ratio, microhardness, and surface quality of DMLS components. The surface roughness under cryogenic conditions can offer a better surface finish (reduced from 5.94 μm to 0.259 μm) with low grinding forces (reduced by 57%) and temperature as compared to dry grinding (reduced from 5.94 μm to 0.356 μm). Higher microhardness was observed due to an increase in temperature during dry grinding.