Programming Crystallographic Orientation in Additive‐Manufactured Beta‐Type Titanium Alloy
Xuan Luo, Tao Song, A. Gebert, Kai Neufeld, Ivan Kaban, Hongwei Ma, Weisi Cai, H.Z. Lu, Dongdong Li, Ning Li, Yuanyuan Li, Chao Yang
Abstract
Additively manufactured metallic materials typically exhibit preferential <001> or <110> crystallographic orientations along the build direction. Nowadays, the challenge is to program crystallographic orientation along arbitrary 3D direction in additive-manufactured materials. In this work, it is established a technique of multitrack coupled directional solidification (MTCDS) to program the <001> crystallographic orientation along an arbitrary 3D direction in biomedical beta-type Ti-Nb-Zr-Ta alloys via laser powder bed fusion (LPBF). MTCDS can be achieved via directional solidification of coupled multi-track melt pools with a specific temperature gradient direction. This results in continuous epitaxial growth of the β-Ti phase and consequently sets the <001> crystallographic orientation along an arbitrary 3D direction. This way, relatively low elastic modulus values of approximately 60 ± 1.2 GPa are customized along an arbitrary 3D direction. It is expected that MTCDS can be generalized to a wide range of applications for programming specific crystallographic orientations and, respectively, tailoring desired properties of different metallic materials.