Resintered microstructure dependence of mechanical properties of alumina wire processed by controlled fracture forming

The mechanical properties of the CFF-Al₂O₃ wire with respect to the Vickers hardness, the fracture toughness and the fracture/tensile strength have been discussed in the present investigation. Results indicate that the CFF process is valid for fabricating Al₂O₃ wire with enhanced mechanical properties. Residual pores in the resintered microstructure are thought to be fatal in determination of the mechanical properties, but the grain size dependence seems to be insensitive. At presence of porosity lower than 2.0%, the fracture of the CFF-Al₂O₃ wire is controlled by the transgranular mode, and its fracture/tensile strength achieves 1.1 GPa. However, the intergranular mode becomes dominated, resulting in a decrease in strength if porosity is higher than 2.0%.