Texture dependence on the mechanical properties of 18Ni300 maraging steel fabricated by laser powder bed fusion

The crystallographic heterostructure of additive manufactured metals has complicated effects on mechanical properties due to the unique thermal history. Therefore, the texture configuration and deformation behavior of powder bed fusion-laser beam (PBF-LB) 18Ni300 maraging steel after different building orientations (BOs) were investigated by electron backscattered diffraction (EBSD), tensile tests and crystal plasticity finite element simulation. The results showed that the yield strength of 90 degrees samples was 2013.8 MPa, higher than that of 0 degrees (1940.5 MPa) and 45 degrees (1847.1 MPa). The higher strength was attributed to the strong (110) 11 BO textures on the 90 degrees building samples. Meanwhile, the elongation was in the order of 3.5% (90 degrees building) < 5.6% (45 degrees building) < 7.6% (0 degrees building) by strain rate of 2.5 x 10-4 s-1, which was attributed to the dynamic recovery process of PBF-LB 18Ni300 maraging steel in strain hardening stage I for different crystallographic orientations. The single crystallographic orientation couldn't coordinate the plastic deformation of the 90 degrees building specimen, which resulted in fracturing under a small strain. In contrast, the diversified crystal textures contributed to the sufficient coordinated plastic deformation of the specimens fabricated along 0 degrees building and thus increased the overall elongation to fracture.

Automated summary

The crystallographic heterostructure of additive manufactured metals has complicated effects on mechanical properties due to the unique thermal history. The texture configuration and deformation behavior of powder bed fusion-laser beam (PBF-LB) 18Ni300 maraging steel after different building orientations (BOs) were investigated. The results showed that the yield strength and elongation of the materials were significantly affected by the building orientation.