Comparison of microstructure and deformation mechanisms of pure titanium fabricated via additive manufacturing using gas atomization and hydrogenation dehydrogenation powder

The rapid solidification in the laser powder bed fusion (LPBF) additive manufacturing imparts titanium (Ti) with distinct microstructure and properties that deviate from those achieved through conventional preparation methods, such as powder sintering and forging. Compared to the low-oxygen pure Ti fabricated by gas atomization (GA) Ti powder, the LPBF-fabricated pure Ti using high-oxygen hydrogenation dehydrogenation (HDH) Ti powder displays a superior strength and ductility. To reveal the cause of this anomaly, EBSD, in-situ EBSD, and TEM were employed to uncover the deformation mechanism of them. During the tensile deformation, the crystal structure of pure Ti undergoes rotation, accompanied with propagation of dislocation. Meanwhile, the abundant wave <a> and <a+c> dislocation in LPBF-fabricated HDH Ti will contribute to the enhancement of both strength and ductility. This work provides insight to fabricate low-cost, and high-performance Ti.