Properties and Interface Structures of Ni and Ni-Ti Alloy Toughened Al2O3 Ceramic Composites

Ni/Al2O3 and Ni-Ti/Al2O3 composites sintered in different atmospheres
are investigated Argon as a sintering atmosphere is found to be more
beneficial to the fracture toughness of the composites than CO. Ni
inclusions at 12 vol.% enhance the fracture toughness up to 36%,
corresponding to a fracture energy twice that of the alumina matrix,
whereas titanium alloying to Ni makes a negative contribution to the
mechanical behaviour. The interfacial structures of Ni/Al2O3 and
Ni-Ti/Al2O3 are studied by using electron microscopy. The titanium
distribution at the interfaces is studied and correlated to the
mechanical properties.