CERAMIC COMPOSITES WITH A DUCTILE NI3AL BINDER PHASE

Composites of B-doped ductile Ni3Al alloys with both non-oxide (WC, Ti C) and oxide (Al2O3) ceremic powders were produced by hot-pressing. Th e Ni3Al alloys wet the non-oxide ceramic powders well and form a semi- continuous intergranular phase. However, the Ni3Al alloys do not wet t he oxide powders well and tend to form discrete ''islands'' of the met allic phase. Mechanical property testing showed the flexural strength is retained to temperatures of at least 800 degrees C. The fracture to ughness and hardness were found to be equal to or higher than comparab le Go-based hardmetal systems. Initial corrosion tests showed excellen t resistance to acid solutions.