In-situ formation of TiC nanoparticles in selective laser melting of 316L with addition of micronsized TiC particles

316L stainless steel has a wide range of engineering applications. However, its relatively low yield strength limits its applications. In this work, strengthened 316L stainless steel was fabricated via selective laser melting (SLM) with the addition of 3 wt% micronsized TiC particles. The grains of 316L are significantly refined to approximately 3 mu m. Although micronsized TiC particles were used as reinforcement, in-situ formed nanosized TiC particles were observed. Tensile tests were carried out and the yield strength of SLM 316L-3TiC was 803 MPa-832 MPa with the elongation ranging from 25.8% to 28.5% when fabricated with laser power between 225 W and 275 W. Relative to SLM 316L without TiC particles which has a yield strength of 599 MPa, the strength enhancement is found to be 97 MPa from grain refinement and 140 MPa from Orowan strengthening.

Automated summary

In this study, strengthened 316L stainless steel was fabricated via selective laser melting by adding 3 wt% micronsized TiC particles, resulting in significantly improved yield strength. Nanosized TiC particles were observed to form in-situ during the process, leading to further strengthening effects.