Microstructure and mechanical properties of Al2O3-Cu-Ni hybrid composites fabricated by slip casting

This work focuses on developing the fabrication method of hybrid composites based on Al2O3-Cu system with the addition of nickel phase. The composites were prepared by slip casting and the slurries with a high concentration of solid content were used. The sintered composites were characterized by XRD, SEM and EDX. Selected physical proprieties, namely hardness, fracture toughness and bending strength were also determined. The microstructure and its influence on the mechanical properties were investigated. XRD analyses revealed that the obtained composites contained Al2O3, Ni, Cu and solid solution CuNi phases. The use of slip casting method allowed the production of the composites characterized by relative density of similar to 96%. An increase in metallic phase concentration caused a decrease in Vickers hardness and increased the fracture toughness of the Al2O3-Cu-Ni materials compared to the Al2O3 samples. The results with high cognitive value and application potential were obtained. This research enabled the foundations of an innovative method of forming hybrid composite structures, which combined the best features of ceramics (hardness, resistance to high temperature) with metal properties (crack resistance, good electrical conductivity). This type of composite can be used for temperature, conductivity and flow sensors.