The microstructure and mechanical properties of deposited-IN718 by selective laser melting

Selective laser melting (SLM) technology based on powder bed has been used to manufacture IN718 samples. The starting material, manufacturing processes, heat treatment and characterization procedures of mechanical properties are presented. It is found that the microstructure is crucial for the mechanical properties of IN718. A regular microstructure with good metallurgical bonding, minimal defects and fine dendritic grains is formed by SLM. After heat treatment, the regular dendritic structure disappears and a needle-like δ phase precipitates at grain boundaries when γ′ and γ″ phases dissolve in the matrix. The microhardness of all samples shows directional independent. The tensile strengths and ductility of SLM + HTed IN718 at room temperature are comparative with those of the wrought IN718.

► We study microstructure and mechanical properties of IN718 by selective laser melting. ► The micro-hardness for all samples shows directional independent. ► The tensile properties of SLM + HTed IN718 are comparative with those of wrought IN718. ► Mechanical properties depend on metallurgical quality, grain size and heat treatment.