Investigation on mechanism of surface tension on morphology of melt track in selective laser melting processing

Insight into the physical mechanism in the process of selective laser melting is essential to improve the quality of parts, and meanwhile, the existing research on process parameters for new materials is lengthy and complex, it often takes a lot of time and effort. In this paper, the influence mechanism of surface tension on the morphology of melt track under different boundary conditions is analyzed, and an interval scan strategy is developed to improve the relative density of parts. The experimental results show that laser power and other process parameters can be determined conveniently via single-track test and multi-track test according to the morphology of melt track. The sample built with stainless steel powder was tested on mechanical and physical properties, resulting in an ultimate tensile strength in vertical direction of 1100 MPa and a relative density of almost 100%.