Influence of the microstructure on mechanical properties of SLM additive manufacturing Fe-based bulk metallic glasses.

• Manufacturing bulk metallic glass (BMG) by selective laser melting (SLM). • Process parameters of SLM-BMG. • Crystallization analysis in the manufacturing process of BMG. • Annealing of metallic glass. • Effect of crystallization on mechanical properties. Fe-based bulk metallic glass (BMG)(FeCrMoWMnSiBC) was produced by selective laser melting (SLM) successfully in this study. The best parameters were determined through extensive experiments. The relative density (95%) and amorphous rate (95.47%) samples were obtained by this parameter. The analysis of the microstructure reveals that the crystalline phases in the heat affected zone (HAZ) are mainly α-Fe and M 23 (CB) 6 phases, and co-exist with the amorphous phases. The Heat treatment is employed to study the crystallization behavior of amorphous phases. The α-Fe phase, as the primary phase, grows into a submicron crystal phase under the action of multiple thermal cycles. Nanoindentation test results show that the hardness of the amorphous phase is higher than that of the nano-grain region, and the hardness of the nanocrystalline region is higher than that of the submicron-grain region. The free volume content is different and the amorphous phase is not uniform due to the complex thermal cycle. The maximum hardness occurs in the amorphous phase with 22.6 GPa. [ABSTRACT FROM AUTHOR]