Effects of ductile cobalt on fracture behavior of Al2O3–TiC ceramic

Ductile cobalt-cladded Al2O3 and TiC powder were prepared using a chemical deposition method. The mixture of Co-cladded Al2O3 and TiC powder (about 70 wt.% Al2O3–Co + 30 wt.% TiC-Co) was hot-pressed into an Al2O3–TiC–Co ceramic sample. Results presented in this paper demonstrated that ductile cobalt could clad the Al2O3–TiC ceramic grains and strengthened the interfacial bonding of ceramic grains. The fracture toughness of Al2O3–TiC–Co ceramic has been improved considerably, compared with Al2O3–TiC ceramic (about 70 wt.% Al2O3 and 30 wt.% TiC). The fracture surface of Al2O3–TiC–Co ceramic sample exhibited some degrees of plastic deformation, which improved the fracture behavior, although a typical transgranular fracture appeared within the coarse grains.