Microstructure and mechanical properties of FeSi ₂ /316L stainless steel formed by selective laser melting

Abstract This study investigates the effect of FeSi 2 addition on the microstructure and mechanical properties of 316L stainless steel fabricated via Selective Laser Melting (SLM). FeSi 2 /316L composite samples with varying FeSi 2 contents (0 wt.%, 1 wt.%, 3 wt.%, and 5 wt.%) were produced and systematically analyzed. The results demonstrate that FeSi 2 addition significantly alters the microstructure by refining the cellular substructure and promoting the formation of ferrite phases. The introduction of Si enhances solid solution strengthening, while phase transformation from austenite to ferrite further improves mechanical properties. Consequently, yield strength and tensile strength exhibit a continuous increase with FeSi 2 addition, reaching 718.61 MPa and 890.97 MPa, respectively, in the 5 wt.% FeSi 2 sample. Meanwhile, the fracture elongation initially increases to 36.50 % at 1 wt.% FeSi 2 and then decreases with higher FeSi 2 content. These findings indicate that FeSi 2 addition effectively enhances the strength and hardness of 316L stainless steel while maintaining acceptable ductility, making it a promising reinforcement strategy for SLM-processed stainless steels.