Parameter optimization of selective laser melting fabricated titanium alloy using skin-core and triple contour scanning strategy

In this paper, the skin-core combined with the triple contour method is proposed to solve the density and roughness problems of selective laser melting. Based on the skin-core strategy, the surface roughness is optimized by laser parameter adjustment, and the high-quality side-surface formation is achieved by the triple contour method. The results showed that the relative density increases first and then decreases with increasing in-skin energy density, and surface roughness decreases with increasing up-skin energy density. The effects of the skin-core parameters have been analyzed. In addition, a triple contour scanning strategy was also conducted, and the variation of surface roughness caused by the different number of contours has been analyzed, along with the fabrication of the Ti6Al4V denture bracket. Results showed that the inclined surface roughness could be improved by the triple contour method to an average roughness (Ra) of 3.5 μm. An average surface roughness of less than 4.3 μm and a relative density of 99.8% have been achieved at the same time using the skin-core and triple contour strategy. The curved surface and overhanging structure quality of the denture bracket was also improved. This work provided a novel approach for the additive manufacturing of a medical titanium alloy.