Microstructural Characterization of Spark Plasma Sintered In Situ TiB reinforced Ti Matrix Composite by EBSD and TEM

摘要

The spark plasma sintered in situ TiB reinforced titanium metal matrix composite was investigated by EBSD and TEM. The sintered composite consists of 30.8 percent alpha-Ti phase, 55.7 percent beta-Ti phase and 12.9 percent in situ TiB reinforcements. Most of the TiB whiskers distributed along phase boundaries between alpha-Ti and beta-Ti, others located within alpha-Ti and beta-Ti grains. Some beta-Ti grains with parallel TiB whiskers were observed in the orientation imaging micrograph (OIM). The TiB grows along [010] direction and forms whisker with a hexagonal cross-section. The [010] direction of paralleled TiB whiskers is parallel to [111] direction of cubic beta-Ti. High density stacking faults are formed in 100_(TiB) planes to minimizing the lattice mismatch between TiB and the Ti matrix.