Abstract
Highly toughened nickel dispersed alumina-based nanocomposites were fabricated using a soaking method based on a previously proposed toughening mechanism of nanocomposites. Commercially available gamma-alumina agglomerate with high porosity was used as a starting material. Nickel nitrate solution was penetrated into the nano-pores of the gamma-alumina agglomerate using this new technique. The alumina-nickel composite powder with alpha-alumina seeds was then sintered using a pulse electric current sintering technique. The sintered materials were annealed to disperse dislocations generated around the nano-particles into alumina grains. The maximum fracture toughness of 7.6 MPa.m1/2 was about two times higher than that of dense alumina. 6 refs.