Structure and properties study of in-situ TiC reinforced 316L materials prepared by laser melting deposition based on Ti₃SiC₂ decomposition

As the service performance requirements for metal components in diverse high-tech industries continue to escalate, a myriad of specialized operational environments pose increasingly formidable challenges to the comprehensive performance of various components. To address these challenges and further enhance the mechanical properties of 316L stainless steel, expand its application range, we have developed in-situ TiC reforced 316L composites. In this paper, we propose a novel method for the fabrication of grain boundary-dispersed, in-situ generated TiC-reinforced 316L metal matrix composites (MMC) through laser melting deposition (LMD), leveraging the decomposition reaction of Ti₃SiC₂. Samples with different TiC contents were prepared, and their microstructures post-LMD were closely analyzed. Furthermore, the underlying enhancement mechanism of in-situ TiC on the mechanical properties of these samples was thoroughly investigated. The results demonstrate that the in-situ TiC particles are uniformly dispersed along grain boundaries, functioning as additional nucleation sites. This enhances the nucleation rate significantly and contributes to grain refinement. Compared with pure 316L material, the hardness and wear resistance of the composite material are greatly improved, and the hardness increased by up to 35.66 %. In-situ TiC can effectively improve the overall performance of 316L.