High-pressure and high-temperature fabrication of TC4–B4C composites: enhanced mechanical properties and environmental resistance

Ti6Al4V (TC4) titanium alloy is often limited by its insufficient strength and inadequate high-temperature oxidation resistance under demanding service conditions. The introduction of ceramic reinforcing phases to form titanium matrix composites (TMCs) presents an effective approach for enhancing its overall performance. In this study, high-pressure and high-temperature (HPHT) processing (5.5 GPa, 1000/1800 °C) was applied to sinter pure TC4 powder and TC4 powder doped with 1 wt% B 4 C, with systematic investigation of their microstructural evolution and properties. The results demonstrate that HPHT treatment significantly improves the density, hardness, and compressive strength of pure TC4. For example, after treatment at 1800 °C, pure TC4 reached a hardness of 471 HV and a compressive strength of 1720 MPa, exceeding the properties of cast TC4 (305 HV, 997 MPa). The TC4–1 wt% B 4 C composite sintered at 1800 °C exhibited even higher hardness (553 HV) and compressive strength (1875 MPa). Importantly, the composite also demonstrated superior electrochemical corrosion resistance and improved oxidation resistance at 700 °C compared to pure TC4. This work confirms that HPHT is an effective technique for fabricating high-performance TMCs, offering a viable strategy for simultaneously enhancing mechanical strength and environmental resistance.