(1. 太原理工大学 先进镁基材料山西省重点实验室，太原 030024；
2. 哈尔滨工业大学 金属精密热加工国家级重点实验室，哈尔滨 150001)
摘 要: 采用真空感应熔炼技术制备不同体积分数(TiBw+TiCp)/Ti复合材料，研究该系列复合材料在600~750 ℃高温拉伸力学行为。结果表明：(TiBw+TiCp)含量由0增加到7.5%(体积分数)时，(TiBw+TiCp)/Ti复合材料基体初始β晶粒和α片层得到显著细化；TiBw及TiCp的原位生成显著提高了基体合金的抗拉强度，并随(TiBw+TiCp)体积分数的增大而增大；随着拉伸温度升高，(TiBw+TiCp)/Ti复合材料抗拉强度降低而塑性增加，TiBw及TiCp对基体的强化作用主要源于细晶强化、载荷传递强化；(TiBw+TiCp)/Ti复合材料在600~700 ℃的断裂机制为TiBw和TiCp的断裂在750 ℃为增强相与基体间界面脱粘。
关键字: 钛基复合材料；显微组织；高温拉伸性能；失效机理
（1. Shanxi Key Laboratory of Advanced Magnesium-based Materials, Taiyuan University of Technology, Taiyuan 030024;
2. National Key Laboratory for Precision Hot Forming of Metals, Harbin Institute of Technology, Harbin 150001）
Abstract:Titanium matrix composites reinforced with different volume fractions of (TiBw+TiCp) were prepared by vacuum induction melting technology, the high temperature tensile mechanical behavior of (TiBw+TiCp)/Ti composites at 600~750 ℃ was investigated. The results indicate that the prior β grain size and α lath width are gradually refined with the (TiBw+TiCp)/Ti (volume fraction) increasing from 0 to 7.5%. The in situ TiBw and TiCp can improve the ultimate tensile strengths of the matrix alloy significantly, and then increase with the increase of (TiBw+TiCp) volume fraction. With the increase of the tensile temperature, the ultimate tensile strength decreases while the elongation increases. The strengthening effects of (TiBw+TiCp) on matrix alloy are mainly attributed to the grain refinement, load transfer and solid solution of C. The fractograph characteristic of the composites reveals that fracture of TiBw and TiCp is the main failure mechanism of the composites at 600-700 ℃ while interfacial debonding dominates the fracture mechanism of the composites at 750 ℃.
Key words: titanium matrix composite; microstructure; high temperature tensile property; failure mechanism
