INTERCONNECTED METAL-CERAMIC COMPOSITES BY CHEMICAL MEANS

Using a sol-gel technique, Ni/alpha-Al2O3 composites with ceramic content ranging from 33-95 vol.% have been synthesized. The process involves dispersing the metal and ceramic precursors in solution followed by calcination in a reducing environment. Fully dense composites are obtained by hot pressing at 1,400 degrees C in an oxygen partial pressure of 10(-12) atm. For the composites containing 20 vol.% metal or higher, the metallic phase was been found to be completely continuous. All of the composites exhibited enhanced fracture toughness behavior relative to the pure ceramic.