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Indexed by:期刊论文

Date of Publication:2018-03-15

Journal:JOURNAL OF ALLOYS AND COMPOUNDS

Included Journals:SCIE、EI

Volume:737

Page Number:221-229

ISSN No.:0925-8388

Key Words:Biomaterials; beta-Titanium alloys; alpha '' martensite; Oxygen; Tensile properties

Abstract:The effect of oxygen addition on microstructures and mechanical properties of Ti-7.5Mo (wt.%) alloy has been investigated. The series of Ti-7.5Mo-xO (x = 0, 0.2, 0.3, 0.4 and 0.5 (wt.%)) alloys were solution-treated at 1173 K for 1 h followed by water quenching. Microstructure characterizations were performed by means of X-ray diffraction, scanning electron microscope, as well as transmission electron microscope. The as-quenched microstructure of each alloy was mainly composed of internally twinned alpha'' martensite. The twinning structures in alloys with oxygen contents of zero and 0.5 wt% were both identified as {111}(alpha'')-Type I twinning. The precipitated alpha plates were observed in alloys with higher oxygen contents (>= 0.4 wt%). This is attributed to the alpha-stabilizing effect by the interstitial oxygen atoms, as confirmed by the differential scanning calorimeter measurements. Based on the results of Vickers micro-hardness tests and tensile tests, the hardness, yield strength, ultimate tensile strength, and Young's modulus increased with increasing the oxygen content, while the total elongation and uniform elongation decreased. This is ascribed to the solid-solution strengthening by the addition of oxygen atoms. The present study revealed that Ti-7.5Mo alloy with oxygen content less than 0.3 wt% exhibits an excellent combination of high yield strength and elongation, as well as low Young's modulus; the alloy has good potential as biomedical materials. (C) 2017 Elsevier B.V. All rights reserved.