Anisotropy of mechanical properties response on crystallographic features of GH5188 superalloy fabricated by laser powder bed fusion

The relationship between the crystallographic features and the anisotropic mechanical properties of a Laser Powder Bed Fusion (LPBF) fabricated GH5188 alloy were investigated. For this purpose, the LPBF-ed GH5188 alloy was subjected to a tensile test in two different tensile axis orientations, perpendicular and parallel to the building direction, which we call “horizonal” and “vertical” orientations correspondingly. The techniques of EBSD and TEM were employed to characterize the different strained samples. The results show that the LPBF-ed GH5188 alloy exhibits a<001>fiber texture with elongated grains along the building direction. Compared to the vertical samples, the horizonal samples acquire a higher Taylor factor and a higher KAM (kernel average misorientation) value during deformation, which lead to a better yield strength and a higher strain hardening rate. Furthermore, the texture of the deformed samples revealed that the horizonal samples have a better coordinated deformability, which leads to higher ductility compared to the vertical samples.