Effects of parameters on surface roughness of samples by selective laser melting

Abstract

During fabrications of metal parts by selective laser melting (SLM) technology, the roughness of every melted layer affects not only the following powder coating process but the dimension precision of final parts. The main processing parameters used to control the surface roughness of melted layers are laser power, scanning velocity and overlap ratio. In experiments, an orthogonal experimental design on the above parameters was employed to find the rules of the surface roughness with SLM processing parameters. The results show that the overlap ratio and the laser energy density are two important factors to affect the surface roughness of cladding layers. Especially, the effect of laser energy density on the roughness is different under different overlap ratios. For the overlap ratio of 30% or 40%, the roughness Ra decreases with the increase of laser energy density. But for the overlap ratio of 50%, the roughness value Ra increases with the increase of laser energy density. The roughness can be adjusted by combining different laser parameters to obtain good sample surface in our experiments.During fabrications of metal parts by selective laser melting (SLM) technology, the roughness of every melted layer affects not only the following powder coating process but the dimension precision of final parts. The main processing parameters used to control the surface roughness of melted layers are laser power, scanning velocity and overlap ratio. In experiments, an orthogonal experimental design on the above parameters was employed to find the rules of the surface roughness with SLM processing parameters. The results show that the overlap ratio and the laser energy density are two important factors to affect the surface roughness of cladding layers. Especially, the effect of laser energy density on the roughness is different under different overlap ratios. For the overlap ratio of 30% or 40%, the roughness Ra decreases with the increase of laser energy density. But for the overlap ratio of 50%, the roughness value Ra increases with the increase of laser energy density. The roughness can be adjusted b...