Using a sol-gel technique, Ni/alpha-Al2O3 composites with ceramic cont
ent ranging from 33-95 vol.% have been synthesized. The process involv
es dispersing the metal and ceramic precursors in solution followed by
calcination in a reducing environment. Fully dense composites are obt
ained 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 highe
r, the metallic phase was been found to be completely continuous. All
of the composites exhibited enhanced fracture toughness behavior relat
ive to the pure ceramic.