Effect of interlayer scan rotation on structure-property relationship of directed energy deposited CoCrNi medium entropy alloy

Abstract

Laser-based Additive Manufacturing (AM) is sought to be a prevalent technique to synthesize medium to high entropy alloys. However, the anisotropy, temperature distribution, and residual stresses in Laser-based AM are some of the major problems that need to be addressed. The effect of interlayer scan rotation on microstructure, texture evolution, and tensile properties of laser-based directed energy deposited CoCrNi are investigated in this study. The electron backscatter diffraction studies revealed the strong 〈001〉 cubic crystallographic texture along the build direction (YZ-plane) without scan rotation. However, there is no preferred grain orientation observed with interlayer scan rotations. The 〈111〉 fiber texture and 〈111〉〈101〉 fiber texture, respectively, are obtained with 67° and 90° scan rotation strategies. The randomized grain orientation due to fiber texture formation enhanced strength significantly with little improvement in ductility. In addition, the substructure refinement is also observed after incorporating scan rotation. Moreover, the present work suggests that nearly isotropic strength and elongation are obtained with 67° rotations. © 2024 Elsevier Inc.