Morphology Characteristics and Mechanical Properties of Nano/Micron Calcium Hexaboride Sintered Body

Nano/Micron Calcium Hexaboride (CaB6) composite ceramics with different CaB6 nanopowder additions were prepared under 1750℃, 32MPa for 5min in vacuum. Influences of CaB6 nanopowders on morphology and mechanical properties of sintered bodies were investigated. Composite ceramic with 10wt% CaB6 nanopowder addition has the highest compactness degree and mechanical properties, whose hardness, bending strength and fractural toughness are 92.6 HRA, 331.7MPa and 3.06MPa·m1/2, respectively, better than those of CaB6 ceramics without nanopowder adding or those of reinforced by Ni as sintering additive. The proper amount of nano-particles filled in the micron grain boundaries and the formation of “inner crystal” result in the improvement of compactness and mechanical properties for the CaB6 sintered body.