Microstructure and properties of TiB2-reinforced Ti–35Nb–7Zr–5Ta processed by laser-powder bed fusion
Rodolfo Lisboa Batalha, Vitor Eduardo Pinotti, Omar O. S. Alnoaimy, Weverson Capute Batalha, Tobias Gustmann, Konrad Kosiba, S. Pauly, Claudemiro Bolfarini, Cláudio Shyinti Kiminami, Piter Gargarella
Abstract
Abstract The Ti–35Nb–7Zr–5Ta (wt%, TNZT) alloy was reinforced with TiB 2 and synthesized by L-PBF. The relatively small TiB 2 particles change the solidification structure from cellular to columnar-dendritic and lead to submicron TiB precipitation in the β matrix. This results in pronounced grain refinement and reduction of texture. However, the microstructure of the additively manufactured TNZT-TiB 2 is still different from the as-cast, unreinforced TNZT, which contains equiaxed and randomly oriented grains. The β phase is less stable in the as-cast samples, leading to stress-induced martensitic transformation and recoverable strain of 1.5%. The TNZT with 1 wt% of TiB 2 presents significantly higher compressive strength ( σ YS = 495 MPa) compared to unreinforced samples ( σ YS = 430 MPa), without sacrificing ductility or altering Young’s modulus ( E ≈ 46 GPa). The addition of a small fraction of TiB 2 to the TNZT alloy synthesized by L-PBF is a promising alternative for manufacturing sophisticated components for biomedical applications. Graphical abstract