Properties of 316L formed by a 400 W power laser Selective Laser Melting with 250 mu m layer thickness

摘要

The performance and quality of SLM by using thicker layers of thickness 250 pm were investigated. The fine powder used can effectively reduce the pore area during SLM. Single-track experiments were conducted to select the optimal combination of exposure time and point distance to narrow down the process parameter windows. In multi-layer fabrication, experimental groups with higher relative densities of 99.99% were observed, and the maximum building rate reached 9 mm(3)/s. Auxiliary processing technology, such as surface remelting, can greatly improve surface quality and reduce surface roughness. The microstructures are mainly equiaxed crystals and columnar crystals with a ratio greater than 1. The average values of the ultimate tensile strength (UTS), yield strength (YS) and elongation (EL) are 670 MPa, 474 MPa and 26%, respectively. Hence, the overall performance is better by using thicker layers. (C) 2019 Elsevier B.V. All rights reserved.