High temperature performance of TiB/(Ti-6.5Al-2Zr-1Mo-1V-0.5Si) composites affected by the TiB architecture

The effect of TiB architecture on the high temperature performance of Ti-6.5Al-2Zr-1Mo-1V-0.5Si (TA15+Si) composites was investigated. Three types of composites were designed: TiB/(TA15+Si) with network architectured TiB, TA15+TiB+Si with homogeneous architectured TiB, and TiB/(TA15+TiB+Si) with network plus homogeneous architectured TiB. For normal tensile properties below 650 °C, TiB with homogeneous architecture can strengthen the composites efficiently through the load transfer effect. However, when the testing temperature reached 650 °C, the softening of the TiB-TA15 interface became pronounced. While for the creep properties, the network architectured TiB/(TA15+Si) composite had the lowest steady state creep rate at temperatures ranging from 550 °C to 700 °C. During the long term creep process, the α/β interface was the location where creep cavities were most prone to form. The TiB with a homogeneous architecture was more likely to have a negative effect on the creep properties due to stress/strain concentration and impeding grain deformation.