热变形及固溶时效态含硼高温钛合金的组织及性能研究

    Microstructure and Properties of Boron Containing High Temperature Titanium Alloy in Thermal Deformation and Solution Aging States

    • 摘要: 研究了热变形和不同固溶时效态含硼高温钛合金的显微组织及拉伸性能,分析了室温及高温拉伸过程中含硼高温钛合金的断裂特征,并探究了合金强化机制。结果表明:不同状态下含硼高温钛合金中晶须分布形态、位置及尺寸无显著差异,热变形态基体显微组织为细小等轴状,两相区固溶处理后初生α相回溶,转变为双态组织;固溶后冷却速率主要影响β转变组织在后续时效过程中次生α相的析出。热变形+热处理态含硼高温钛合金强度优势显著,采用两相区固溶淬火并时效的热处理工艺可获得室温抗拉强度达1547 MPa、650 ℃抗拉强度达745 MPa的超高强度。含硼高温钛合金优异的强度主要得益于晶须的承载强化和基体显微组织细化,其中固溶淬火后时效过程中形成的极细紊乱β转变结构是含硼高温钛合金获得超高强度的主要原因。

       

      Abstract: The microstructure and tensile properties of boron containing high temperature titanium alloy in hot deformed state and different solution+aged states were studied. The fracture characteristics of boron containing high temperature titanium alloy in room temperature and high temperature tensile processes were analyzed and the strengthening mechanism of the alloy was investigated. The results show that there is no significant difference in the distribution, location and size of whisker in boron containing high temperature titanium alloys under different states. The microstructure of the matrix is fine equiaxed grain, and the primary α phase is dissolved after solution treatment in the two-phase zone, and it is transformed into a dual-state structure. The cooling rate after solution mainly affects the precipitation of secondary α phase from β transformed tissues during the subsequent aging process. The strength of boron containing high temperature titanium alloy in hot deformation and heat treatment state has remarkable advantages. The tensile strength of 1547 MPa at room temperature and 745 MPa at 650 ℃ can be obtained by the heat treatment process of two phase solution quenching and aging. The excellent strength of boron containing high temperature titanium alloy is mainly due to the bearing strengthening of whisker and matrix microstructure refinement, and the extremely fine disordered β transition structure formed during aging after solution quenching treatment is the main reason that the boron-containing high-temperature titanium alloy has ultra-high strength.

       

    /

    返回文章
    返回