Clarification of anomalous fatigue softening in biomedical Ti-Nb alloys

2015 Fiscal Year Final Research Report

• Project/Area Number: 26820315
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Structural/Functional materials
• Research Institution: Osaka University
• Principal Investigator: Todai Mitsuharu 大阪大学, 工学(系)研究科(研究院), 助教 (10610800)
• Co-Investigator(Renkei-kenkyūsha): NAKANO TAKAYOSHI 大阪大学, 大学院工学研究科, 教授 (30243182)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: 生体材料 / Ti合金 / ω相変態 / 単結晶 / 疲労試験 / バリアント

Outline of Final Research Achievements

The cyclic deformation behavior and dislocation microstructure in Ti-xNb single crystals were investigated by a fatigue test and the subsequent observation of transmission electron microscopy (TEM), respectively.
An anomalous softening appears in the Ti-34Nb crystal fatigued at a total strain amplitude of Δε = 0.9% and number of cycles, number of cycle over 200 accompanied by the precipitation of ω phase. In contrast, neither fatigue softening nor precipitation of ω phase was found out in the Ti-40Nb crystal. It is concluded that the fatigue softening in the Ti-34Nb crystal is closely related to the stability of β matrix and the precipitation of ω phase induced by dislocations.

Free Research Field

生体材料