Title

Microstructure evolution and deformation mechanism of α+ β dual-phase Ti-xNb-yTa-2Zr alloys with high performance

Document Type

Journal Article

Publication Title

Journal of Materials Science and Technology

Volume

131

First Page

68

Last Page

81

Publisher

Elsevier

School

School of Engineering

RAS ID

44774

Funders

National Natural Science Foundation of China (Nos. 52011530181 and 51831011) Shanghai Science and Technology Commission (No. 20S31900100)

Comments

Zhang, T., Wei, D., Lu, E., Wang, W., Wang, K., Li, X., ... & Wang, L. (2022). Microstructure evolution and deformation mechanism of α+ β dual-phase Ti-xNb-yTa-2Zr alloys with high performance. Journal of Materials Science & Technology, 131, p. 68-81. https://doi.org/10.1016/j.jmst.2022.04.052

Abstract

Biomedical β-phase Ti-Nb-Ta-Zr alloys usually exhibit low elastic modulus with inadequate strength. In the present work, a series of newly developed dual-phase Ti-xNb-yTa-2Zr (wt.%) alloys with high performance were investigated in which the stability of β-phase was reduced under the guidelines of ab initio calculations and d-electronic theory. The effects of Nb and Ta contents on the microstructure, compressive and tensile properties were investigated. Results demonstrate that the designed Ti-xNb-yTa-2Zr alloys exhibit typical characteristics of α+β dual-phase microstructure. The microstructure of the alloys is more sensitive to Nb rather than Ta. The as-cast alloys exhibit needle-like α′ martensite at a lower Nb content of 3 wt.% and lamellar α′ martensite at an Nb content of 5 wt.%. Among the alloys, the Ti-3Nb-13Ta-2Zr alloy shows the highest compressive strength (2270 ± 10 MPa) and compressive strain (74.3% ± 0.4%). This superior performance is due to the combination of α+β dual-phase microstructure and stress-induced α" martensite. Besides, lattice distortion caused by Ta element also contributes to the compressive properties. Nb and Ta contents of the alloys strongly affect Young's modulus and tensile properties after rolling. The as-rolled Ti-3Nb-13Ta-2Zr alloy exhibits much lower modulus due to lower Nb content as well as more α" martensite and β phase with a good combination of low modulus and high strength among all the designed alloys. Atom probe tomography analysis reveals the element partitioning between the α and β phases in which Ta concentration is higher than Nb in the α phase. Also, the concentration of Ta is lower than that of Nb in the β phase, indicating that the β-stability of Nb is higher than that of Ta. This work proposes modern α+β dual-phase Ti-xNb-yTa-2Zr alloys as a new concept to design novel biomedical Ti alloys with high performance.

DOI

10.1016/j.jmst.2022.04.052

Access Rights

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Research Themes

Natural and Built Environments

Priority Areas

Engineering, technology and nanotechnology

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