Research on forming characteristic of pulsed selective laser melting

Abstract

To investigate the forming characteristic and obtain a greater process control of the pulsed selective laser melting (P-SLM), the single melting point and single-track and multi-layer block experiments were conducted to investigate the influence of various process parameters on the forming process of P-SLM. A rapid method for the optimization of parameters based on molten pool characterizations is developed. Furthermore, the relationships between the two key process parameters (exposure time, point distance) and the geometric characteristics of single tracks are investigated by linear regression analysis. The research on the surface morphology and the overlapping rate of single-track experiments shows that the value of P-SLM scanning speed is determined by the diameter of single melting point. With relatively high forming efficiency, the highest value of density can be up to 99.99% when the process parameter of exposure time is 80 μs, the point distance is 48 μm, and the hatch space is 80 μm. The yield strength, tensile strength, and elongation of the best sample are 533 Mpa, 647 Mpa, and 40%, respectively, which are higher than that of 316L stainless steel forgings standard (ASTM A473-13).