Mechanical and tribocorrosion properties of DLP-printed AISI 316L stainless steel

Digital light processing (DLP) has been widely utilized in ceramic additive manufacturing, while research on its application for fabricating metallic materials remains in the initial stages. In this paper, the geometric accuracy, mechanical and tribocorrosion properties of AISI 316 L prepared by DLP (DLP-316L) are systematically evaluated. DLP technology exhibits high forming accuracy in additive manufacturing of metal parts, with dimensional errors controllable within ± 70 μm and surface roughness of 1.6 μm. The microstructure of DLP-316L comprises austenite with minor δ-ferrite and M 23 C 6 /M 7 C 3 carbides. The carbides originate from residual carbon due to incomplete decomposition of photosensitive resin during debinding, while δ-ferrite forms during prolonged high-temperature sintering at 1380 °C for 6 h. It not only has a high ultimate tensile strength of 543.5 MPa, but more importantly, the fracture elongation can reach 58.73 %, which is at a high level in the preparation of AISI 316 L using DLP. In addition, the tribocorrosion performance of DLP-316L in 3.5 wt% NaCl solution is better than that of the commercial as-rolled AISI 316 L. This is mainly attributed to the presence of a small amount of high-hardness carbides in the microstructure, which improves the wear and corrosion resistance of the material.