Abstract
The Al2O3/5-20vol%Mo composites were fabricated by hot-pressing a mixture of a-Al2O3 and fine Mo powders under a vacuum. In these composites, nanometer size Mo particles were dispersed within the
Al2O3 grains and relatively large Mo particles, above 1μm, were located at the grain boundaries. Thus, it was confirmed that ceramic/metal nanocomposites could be successfully fabricated with a conventional powder metallurgical process. The addition of Mo particles resulted in the grain growth inhibition of the Al2O3 matrix. A significant improvement in fracture strength and toughness was observed, but they could not be achieved simultaneously. A fracture strength of 884MPa for the Al2O3/7.5vol%Mo composite sintered at 1400°C was obtained. The fracture toughness was improved with increasing Mo content and rising sintering temperature. It obtained a value of 7.21MPa⋅1/2 for the Al2O3/20vol%Mo composite sintered at 1700°C.
