Ablation-Resistance of Combustion Synthesized TiB2–Cu Cermet

摘要

TiB2–Cu ceramic–metal composites were prepared by combustionudsynthesis of elemental titanium, boron, and copper powders.udThe synthesized product consisted of two phases: TiB2 andudcopper. The addition of copper improved the strength andudfracture toughness, thermal expansion coefficient, and thermaludconductivity of TiB2. Thermal shock and ablation resistances ofudTiB2–Cu composites were studied using a plasma torch arcudheater.Monolithic TiB2 failed catastrophically when the plasmaudarc flow reached the specimen surface. However, no cracks wereudfound on the ablation surface of the TiB2–Cu ceramic–metaludcomposites. The fractional mass loss was 4.09% for a TiB2–ud40Cu composite, which was close to the traditionalW/Cu alloys.udVolatilization of metal binder and mechanical erosion of TiB2udwere observed to be the major ablation mechanisms. An ablationudprocess model is proposed for the TiB2–Cu composites.