Processing Condition and Mechanical Properties of Blended Elemental P/M Particulate-reinforced Ti_3Al Intermetallics Matrix Composite

摘要

To improve the high temperature performance of Ti_3Al intermetallics, 10wt percent TiB ceramic particulate reinforced Ti-24Al- 11Nb(at percent) matrix composites have been produced by blended elemental (BE) powder metallurgy method. Pure titanium powder, Nb-Al master alloy powder and TiB_2 ceramic powder were used as the starting materials. TiB particulate reinforcements were dispersed in-situ in the matrix during the vacuum sintering. By using finer starting powder (45#mu#m) and sintering at higher temperature (1823K), homogeneous dispersion of TiB particulates was attained. The density of the composite was also increased with the decrement of the size of starting powders and the increment of the sintering temperature. The results of high temperature tensile and creep tests indicated that high temperature mechanical properties of Ti-24Al-11Nb/TiB composites were superior to those of the unreinforced Ti-24Al-11Nb.