Research on the Forming Process of a Selective Laser Melting-Manufactured 316L Stainless Steel Based on Multi-Index Evaluation

Abstract

This paper investigate a laser processing parameters effects on the tensile properties and surface roughness of a SLM-manufactured 316L stainless steel sample. A multi-index weight model was established using the orthogonal test and entropy weight method. Then, the model assessed the effect of three process factors (scanning speed v, filling laser power P, and scan spacing s). The influence of different combinations of processing parameters on tensile properties and surface roughness was also analyzed. The results revealed that the level of the effects on the sample’s properties from high to low was P, v, and s (P > v > s), respectively. Tensile properties were influenced by laser power and scanning speed first with an increase, followed by a decrease, while scan spacing affected tensile properties with a decrease followed by an increase; the maximum tensile strength was 693 MPa. Surface roughness was affected by filling laser power and scanning power and scanning speed first with a decrease, followed by an increase, while scan spacing affected surface roughness with an increase followed by a decrease. Under experimental conditions, when the laser energy density (E) was 69.44 J·mm−3, the surface roughness of formed parts was the best; Ra was 2.04 μm.