Fabrication of TiB₂/Al composite by melt-SHS process with different content of titanium powder

Melt-SHS (self-propagating high-temperature synthesis), based on the SHS process and oxide reaction method, was used for preparation of TiB2/Al composites. The mass ratio of two reactants, Ti powder/TiO2, in initial powder mixture was varied from 0:1 to 1:0. The results showed that the 5 wt% TiB2/Al composites could be successfully produced by a reaction of aluminum powder, TiO2, and B2O3in Al melt at 950 °C, while the reaction rate was slow. The addition of titanium powder helps to reduce the content of Al2O3and destroy the coating structure of Al2O3covered TiB2particles, which leads to the acceleration of reaction process and improvement of particle concentration. A significant improvement was that TiB2particles were dispersively distributed when the mass ratio of Ti powder/TiO2was 2:3. As a result, the 5 wt% TiB2/Al composites fabricated by melt-SHS process with modified reactants ratio showed excellent tensile properties with the ultimate tensile strength as high as 114.24 MPa. Besides, the composite also showed superior ductility.