Large super-elasticity approaching its theoretically expected value was achieved in Ti-13.3Nb-4.6Mo alloy having an ultrafine-grained β-phase. In-situ synchrotron radiation X-ray diffraction analysis revealed that the dominant yielding mechanism changed from dislocation slip to martensitic transformation by decreasing the β-grain size down to sub-micrometer. Different grain size dependence of the critical stress to initiate dislocation slip and martensitic transformation, which was reflected by the transition of yielding behavior, was considered to be the main reason for the large super-elasticity in the ultrafine-grained specimen.

中文翻译：

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通过超细晶粒化改变Ti-Nb-Mo合金中变形模式的相对易度来获得大的超弹性

在具有超细晶粒β相的Ti-13.3Nb-4.6Mo合金中，达到了接近理论预期值的大超弹性。原位同步辐射X射线衍射分析表明，主要的屈服机理是通过将β晶粒尺寸减小到亚微米而从位错滑移转变为马氏体转变。屈服行为的转变反映了临界应力对晶粒的不同大小依赖性以引起位错滑移和马氏体转变，这被认为是超细晶粒试样中超弹性较大的主要原因。