Microstructure and mechanical properties of in-situ synthesized TiB whiskers reinforced titanium matrix composites by high-velocity compaction

High-velocity compaction (HVC) technology was applied to press titanium-based blended elemental powders containing boron sources of TiB2 and LaB6, and in-situ TiB whiskers reinforced titanium matrix composites (TMCs, TiB/Ti-4.5 Al-6.8 Mo-1.5 Fe) were successfully prepared after vacuum sintering at 1250 °C for 3 h. The effects of forming ability of the blended powders by HVC and TiB volume fraction (5–20%) on microstructure and mechanical properties of composites were studied. The results showed that the blended powders could be pressed by HVC into green compacts with relative density no less than 94%. While the hardness and brittleness of TMCs increased with increasing TiB content, the TMCs with 10% TiB had the maximum tensile strength of 1147 MPa due to the combined effects of a relatively high relative density, a sufficient reinforcement of TiB and a homogeneous microstructure for this composition. The properties of the matrix alloy were also studied.