【摘要】 采用真空感应熔炼技术制备不同体积分数(TiB_w+TiC_p)/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:(TiB_w+TiC_p)含量由0增加到7.5%(体积分数)时,(TiB_w+TiC_p)/Ti复合材料基体初始β晶粒和α片层得到显著细化;TiB_w及TiC_p的原位生成显著提高了基体合金的抗拉强度,并随(TiB_w+TiC_p)体积分数的增大而增大;随着拉伸温度升高,(TiB_w+TiC_p)/Ti复合材料抗拉强度降低而塑性增加,TiB_w及TiC_p对基体的强化作用主要源于细晶强化、载荷传递强化;(TiB_w+TiC_p)/Ti复合材料在600~700℃的断裂机制为TiB_w和TiC_p的断裂在750℃为增强相与基体间界面脱粘。更多还原

【Abstract】 Titanium matrix composites reinforced with different volume fractions of(TiB_w+TiC_p) were prepared by vacuum induction melting technology, the high temperature tensile mechanical behavior of(TiB_w+TiC_p)/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(TiB_w+TiC_p)/Ti(volume fraction) increasing from 0 to 7.5%. The in situ TiB_w and TiC_p can improve the ultimate tensile strengths of the matrix alloy significantly, and then increase with the increase of(TiB_w+TiC_p) volume fraction. With the increase of the tensile temperature, the ultimate tensile strength decreases while the elongation increases. The strengthening effects of(TiB_w+TiC_p) 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 TiB_w and TiC_p is the main failure mechanism of the composites at 600-700 ℃ while interfacial debonding dominates the fracture mechanism of the composites at 750 ℃.更多还原