Ceramic composites with a ductile Ni3Al binder phase

Composites of B-doped ductile Ni3Al alloys with both non-oxide (WC, TiC) and oxide (Al2O3) ceramic powders were produced by hot-pressing. The Ni3Al alloys wet the non-oxide ceramic powders well and form a semi-continuous intergranular phase. However, the Ni3Al alloys do not wet the oxide powders well and tend to form discrete “islands” of the metallic phase. Mechanical property testing showed the flexural strength is retained to temperatures of at least 800 °C. The fracture toughness and hardness were found to be equal to or higher than comparable Co-based hardmetal systems. Initial corrosion tests showed excellent resistance to acid solutions.