Effect of scanning strategy on texture formation in Ni-25 at.%Mo alloys fabricated by selective laser melting

Abstract

Variations in the crystallographic texture in Ni-25 at.%Mo alloys fabricated by selective laser melting with different scanning strategies were designed for the first time. Single-crystalline-like texture with a short-range order of Mo atoms can be produced via bidirectional scanning along one axis (X-scan) and bidirectional scanning with a 90° rotation in each layer (XY-scan), while only fiber texture was formed in bidirectional scanning with a 67° rotation (Rot-scan). The aligned crystal orientation along the build direction can be varied by the scanning strategy; 〈001〉 is preferred in the XY- and Rot-scan samples, while 〈101〉 is preferred in the X-scan sample. The controlling mechanisms of the texture, focusing on the preferential growth directions of the columnar cells and the following epitaxial growth, are discussed. Keywords: Additive manufacturing, Selective laser melting, Texture, Electron backscattering diffraction, Ni-Mo alloy, Short-range order