Multi-scale microstructural investigation of a laser 3D printed Ni-based superalloy

• DOI: 10.1016/j.addma.2020.101220
• Publication Date: 2020-04-25T06:40:44Z
• Authors: Yao Li; Kai Chen; R. Lakshmi Narayan; Upadrasta Ramamurty; Yudong Wang; Juncheng Long; Nobumichi Tamura; Xin Zhou
• Keywords: Lattice (music)

Abstract The heterogeneous microstructure of a laser 3D printed Ni-based superalloy was examined at multiple length scales. The sub-millimeter-sized columnar crystal grains are composed of micron-sized cellular colonies. The crystal grains grow in epitaxy with the substrate under the large temperature gradient and high cooling rate. The cell boundaries, decorated with γ/γ′ eutectics, μ-phase precipitates and high density of dislocations, show enrichment of γ′ forming elements and low-angle misorientations. Dislocations trapped in the intra-cellular regions are characterized as statistically stored dislocations with no detectable contribution to lattice curvature, and are the results of the interaction between dislocations and γ′ precipitates.