【摘要】 对一种新型高强β钛合金热处理过程中初生α相形貌演变和力学性能进行了研究。结果表明:新型合金α/β区双重固溶处理时初生α相在原有近球形晶粒基础上呈现球状生长;固溶后以0.5℃/min冷却速率炉冷,除部分初生α相依然保持近球状生长外,另有部分α相出现了α相端面的"叉型"结构定向生长特征。新型合金α/β区固溶后空冷+时效处理获得的细小等轴或短棒状初生α相与针状次生α相的混合组织具有优异的强-塑性匹配（抗拉强度1300 MPa,延伸率10.5%）。固溶后炉冷+时效处理的合金的抗拉强度为1000 MPa,延伸率为19%,断面收缩率为45%,且具有优异的断裂韧性(≥80 MPa·m^1/2)。认为该合金是一种优良的结构材料。更多还原

【Abstract】 The evolution of primary α phase morphology and mechanical properties of a novel high-strength titanium alloy during heat treatment were investigated. The results show that the primary α phases exhibit a globular growth feature on the basis of the equiaxed α phases under double solution treatment at air cooling process of α/β zone. But abnormal growth of primary α grains occurs in the 0.5℃/min furnace cooling process except that some primary α remains spherical growth, i.e. the other part of α grains evolve into similar "fork" shaped dendritic growth rather than keeping nearly spherical growth trend. The novel titanium alloy has attractive combinations of strength and ductility（≈1300 MPa of ultimate strength with 10.5% of elongation） owing to the microstructures of equiaxed or thin billet-like primary α phase and fine needle-like secondary α phase after α/β solution treatment followed by air cooling plus aging. After α/β solution treatment followed by furnace cooling to low temperature and then aging heat treatment, the new type alloy has an excellent fracture toughness(≥80 MPa·m^1/2), and the elongation and reduction of area remain at about 19% and 45%, respectively, and its corresponding tensile strength is maintained at about 1000 MPa. It can be assumed that the alloy may be a usable structural material.更多还原