Properties and Interface Structures of Ni and Ni-Ti Alloy Toughened Al_2O_3 Ceramic Composites

摘要

Ni/Al_2O_3 and Ni-Ti/Al_2O_3 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/Al_2O_3 and Ni-Ti/Al_2O_3 are studied by using electron microscopy. The titanium distribution at the interfaces is studied and correlated to the mechanical properties.