Abstract

The effect of Cu content on microstructure and mechanical properties of nano-sized Cu dispersed Al_2O_3(Al_2O_3/Cu) nanocomposites was investigated. The nanocomposites with Cu content of 2.5 to 10 vol% were prepared by reduction and hot-pressing of Al_2O_3/CuO powder mixtures. The nanocomposites with Cu content of 2.5 and 5vol% exhibited the maximum fracture strength of 820MPa and enhanced toughness compared with monolithic Al_2O_3. The strengthening was mainly attributed to the refinement of Al_2O_3 matrix grains. The toughening mechanism was discussed by the observed microstructural feature based on crack bridging.

• Keywords: Nanocomposites;Hot pressing;Microstructure;Mechanical properties;