凝胶注模成型多孔氮化硅陶瓷

Preparation of Porous Silicon Nitride Materials by Gelcasting

凝胶注模成型最初用来制备致密材料,本文则利用该方法来制备多孔氮化硅陶瓷。通过测试粉体的Zeta电位曲线以及加入分散剂(聚丙烯酸铵)时浆料的流变曲线,探讨了浆料的胶体特性和流变特性。分析了影响制品气孔率的几个因素。结果表明:粉体的等电点在pH为6附近,Zeta电位最大值在pH为10处。分散剂的加入使浆料的流体类型逐渐接近于牛顿流体。增加分散剂的含量和降低浆料的固含量可以提高制品的气孔率。

Porous materials of silicon nitride were prepared by gelcasting method. Zeta potential of the powders and theologic properties of the slurry with various dispersant contents were studied. The experimental results show that the IEP （isoelectric point） of the p-Si3N4 is at the pH value of 6 and the zeta potential is up to its maximum near pH value of l 0. The style of the suspension is close to Newton fluid gradually when dispersant increases. Porosity of the prepared materials increases with the increase of dispersant content and the decrease of solid loadings of suspension.