Microstructure and mechanical properties of in situ synthesized (TiB + TiC)/Ti matrix composites

TiB and TiC reinforced Ti matrix composites have been produced in situ by common casting and hot-forging technology. The results of optical microscopy, EPMA, TEM and XRD show that there are two reinforcements with different shapes, namely, short-fibre TiB and equiaxed or near-equiaxed TiC particles. TiB whiskers were made to align along the hot-forging direction after hot-forging. The interface between reinforcements and Ti matrix alloy is clean. There isn't interface reaction between TiB and Ti matrix alloy, while there is non-stoichiometric annuli in interface between TiC and Ti matrix alloy. The mechanical properties at room and elevated temperature of Ti matrix composites have been improved at large scale due to the following reasons: TiB whiskers and TiC particles undertaking load, refining of titanium matrix alloy' grains and high density dislocation in Ti matrix alloy.