Comparison of Laser Powder Bed Fusion and Cast Inconel 713 Alloy in Terms of Their Microstructure, Mechanical Properties, and Fatigue Life

Herein, laser powder bed fusion (LPBF) and casting Inconel 713 are used as the experimental materials for comparing the microstructure, mechanical properties, and fatigue characteristics. According to the results, the LPBF specimen has a columnar grain morphology that completely differs from the dendritic structure in the casting specimen, little difference in the hardness of the two specimens. In terms of mechanical properties, the LPBF specimen shows higher strength than the casting specimen but slightly lower ductility. In terms of fatigue characteristics, the LPBF specimen is better than the casting specimen under all loadings. For the LPBF specimen, solution heat treatment is used, which can cause the γ' phase to precipitate on the grain boundary and result in a texture effect. This promotes fracture during tensile and considerably reduces ductility. Nevertheless, the unheated LPBF Inconel 713 exhibits better strength and fatigue properties than casting specimens and can, thus, replace the traditional casting materials in the aerospace industry.