【摘要】 通过冷坩埚悬浮感应熔炼、轧制和固溶热处理制备Ti-8Mo-2Zr、Ti-8Mo-4Nb-2Zr和Ti-8Mo-4Nb-2Zr-2Ta(原子分数/%)钛合金，研究了铌和钽元素的添加对合金显微组织、拉伸性能和变形机制的影响。结果表明：3种合金的组成相均为单一β相，β相晶粒尺寸随着铌、铌+钽元素的添加逐步减小；Ti-8Mo-2Zr合金的变形机制以应力诱发α″马氏体相变和{332}孪生为主，而Ti-8Mo-4Nb-2Zr和Ti-8Mo-4Nb-2Zr-2Ta合金的变形机制以位错滑移为主；变形机制的转变导致合金强度的提高和塑性的降低，铌和钽元素添加产生的细晶强化和固溶强化效应进一步提高了合金的强度，Ti-8Mo-4Nb-2Zr-2Ta合金的抗拉强度高达970 MPa。更多还原

【Abstract】 Ti-8 Mo-2 Zr, Ti-8 Mo-4 Nb-2 Zr and Ti-8 Mo-4 Nb-2 Zr-2 Ta(atom fraction/%) alloys were prepared by cold crucible induction levitation melting, rolling and solution treatment. The effects of Nb and Ta additions on the microstructure, tensile properties and deformation mechanism of the alloys were investigated. The results show that only one single β phase existed in all the three alloys. The β phase grain size decreased in turn with addition of Nb and Nb+Ta. Ti-8 Mo-2 Zr alloy deformed mainly by stress-induced α″ martensitic transformation and {332} twinning, while only dislocation slip appeared in the Ti-8 Mo-4 Nb-2 Zr and Ti-8 Mo-4 Nb-2 Zr-2 Ta alloys. The change of deformation mechanisms led to the increase in alloy strength and decrease in ductility. The grain refinement strengthening effect and the solution strengthening effect produced by additions of Nb and Ta further improved the strength of the alloy; the tensile strength of the Ti-8 Mo-4 Nb-2 Zr-2 Ta alloy was as high as 970 MPa.更多还原