鋳込み成形によるZrO_2-WC複合体の作製とその機械的性質 Preparation and Mechanical Properties of ZrO_2-WC Composites by Slip-casting Technique
In order to study the applicability of a slip-casting technique to preparation of ceramic composites consisting of powders with different specific gravity, the technique was applied to ZrO<SUB>2</SUB>-WC system. During casting process, ZrO<SUB>2</SUB> and WC were afraid to separate due to the difference in their specific gravity, that is, 6.07 for ZrO<SUB>2</SUB> and 15.6 for WC.. For preparing fluidal and thick slurry, the optimum amounts of water and dispersant were determined on the basis of the viscosity and the density of green compacts. The optimum amounts of water and dispersant were 60vol% and 0.35mass%, respectively. The dispersibility was estimated by an EDX analysis and SEM observation. WC powders were found to disperse uniformly in ZrO<SUB>2</SUB> matrix, when the thick slurry consisting of raw powders was cast. The prepared compacts were sintered at a temperature from 1400°C to 1700°C. The density and mechanical properties of composites were improved with an increase in sintering temperature. The bending strength and fracture toughness of the composites sintered at 1700°C were 820MPa and 7.4MPa⋅m<SUB>1/2</SUB>, respectively. The improvement of the boundary between ZrO<SUB>2</SUB> and WC was guessed to make their properties enhanced further.
粉体および粉末冶金 43(7), 885-889, 1996-07-15
Japan Society of Powder and Powder Metallurgy