Ablation-Resistance of Combustion Synthesized TiB2–Cu Cermet

TiB2–Cu ceramic–metal composites were prepared by combustion synthesis of elemental titanium, boron, and copper powders. The synthesized product consisted of two phases: TiB2 and copper. The addition of copper improved the strength and fracture toughness, thermal expansion coefficient, and thermal conductivity of TiB2. Thermal shock and ablation resistances of TiB2–Cu composites were studied using a plasma torch arc heater.Monolithic TiB2 failed catastrophically when the plasma arc flow reached the specimen surface. However, no cracks were found on the ablation surface of the TiB2–Cu ceramic–metal composites. The fractional mass loss was 4.09% for a TiB2– 40Cu composite, which was close to the traditionalW/Cu alloys. Volatilization of metal binder and mechanical erosion of TiB2 were observed to be the major ablation mechanisms. An ablation process model is proposed for the TiB2–Cu composites.