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

• Ti-based blended powder containing hard particles can be well compacted by HVC.
• Dense Ti-based TMCs were prepared by a simple pressing-and-sintering process.
• Effects of TiB content on the microstructure and properties of TMCs were studied.
• The TMCs with 10% vol. TiB has the best comprehensive properties.

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.

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