Microstructure and Physical Properties of an Inconel 718 Alloy Fabricated by Selective Laser Melting (SLM)
J. Li, Z. Y. Zhao, P.K. Bai, H.Q. Qu, B. Liu and M. J. Liang
This study focuses on the microstructure and mechanical properties of the Inconel 718 alloy fabricated by selective laser melting (SLM). The cross-section of the selected laser melted alloy shows an elliptical crystal structure, while the longitudinal section exhibits fine equiaxed crystal structure. Meanwhile, the overlapping area is equivalent to laser remelting treatment, and the strengthening γ” phase (Ni3Nb) is dispersed and precipitated in the substrate, leading to microhardness of the overlapping area is 5.8% higher than that of the non-lapping area. The fast cooling rate promoted the precipitation of γ phase (Ni-Cr-Fe), and significantly improved the properties.
Keywords: Yb fibre laser, Inconel 718, selective laser melting (SLM), microhardness, microstructure