An optimum route to fabricate Al2O3/Cu composites with sound microstructure and desired mechanical properties was investigated. The Al2O3 matrix composites with Cu content of 2.5 to 10 vol.% were prepared by reduction and hot-pressing of Al2O3/CuO powder mixtures. Homogeneous microstructures with nanosized Cu dispersoids and improved fracture strength of 820 MPa could be achieved in the composites with Cu content of 2.5 and 5 vol.%. The influence of the Cu content upon the mechanical properties is discussed based on the observed microstructural characteristics. The toughness increase is explained by crack bridging. The strengthening is mainly attributed to the refinement of Al2O3 matrix grains by the nano-sized Cu dispersion.
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