凝胶注模制备碳化钨多孔陶瓷

Preparation Process of Tungsten Carbide Porous Ceramic by Gel-casting

以甲基丙烯酰胺为单体、聚乙烯亚胺为分散剂,采用凝胶注模工艺制备WC坯体,经1500℃保温2h烧结,获得WC多孔陶瓷。结果表明：PEI含量为0.2%（质量分数）、pH值为9.5时,可以制备固相含量最高为45%（体积分数）的稳定WC浆料;多孔陶瓷孔径呈单峰分布;随着浆料固相含量从25%增加到45%,WC多孔陶瓷的孔隙率从61.8%（体积分数）下降到56.3%,WC多孔陶瓷的抗弯强度在20~40MPa之间。

Porous tungsten carbide （WC） ceramics were prepared by a gel-casting method, then it was sintered at 1 500 for 2 h to get porous WC ceramic. The results show that the maximum solid loading in WC slurry dispersed with polyethyleneimine （PEI） is 45% （in volume fraction）. The WC slurry with the minimum viscosity can be obtained under the optimal condition （i.e., pH value of 9.5 and the dispersant content of 0.2% （in mass fraction））. According to the results by mercury-injection test, the pore size distribution of the ceramics presents a unimodal model. The porosity of WC porous ceramics decreases from 61.8% （in volume fraction） to 56.3% when the solid loading of WC slurry increases from 25% to 45%. The flexural strength of WC porous ceramics is 20 to 40 MPa, This ceramic can be used for machining and the subsequent pressureless reactive melt infiltration.