Ultra-toughened Al2O3-TiC-Co ceramic

Al2O3 and TiC powders in microscale have been coated with a uniform cobalt layer by electroless plating technique under application of ultrasonic wave. Co-coated Al2O3 and TiC powders were then hot-pressed into Al2O3-TiC-Co ceramic by sintering at 1600 °C and 30 MPa for 30 min in vacuum. Results demonstrate that the uniformly distributed Co-phase improved the interfacial bonding of ceramic grains significantly in comparison with Al2O3-TiC (AT30) ceramic and our previous research. The fracture toughness of the new Al2O3-TiC-Co ceramic reaches the value as large as 11.28 MPa m1/2; meanwhile the hardness and bending strength are greatly improved as well. The fracture surface morphology of the Al2O3-TiC-Co ceramic sample shows the characteristics of intergranular fracture.