Synthesis and properties of Al2O3 nanocomposite ceramics toughened by nano metallic particles

Al2O3/Ni composite ceramics toughened by metallic particles was fabricated by the vacuum reduction of Al2O3 and nickel nitrate (Ni(NO3)(2).6H(2)O) mixed powders at 800-1000degrees for 2-4h and hot pressed at 1400degrees similar to 1500 degreesC for 1-2h. Three-point bending strength and facture toughness of the composite were studied. With the increase of Ni content, its flexural strength and facture toughness increases significantly. Microstuctural investigations of the composite revealed that fine nickel particles dispersed homogeneously at the matrix grain boundaries, forming the intergranular nanocomposite.