Yang J, Ferreira JMF, Weng W
Department of Ceramics and Glass Engineering, University of Aveiro, Aveiro, 3810, Portugal
J Colloid Interface Sci. 1998 Oct 1;206(1):274-280. doi: 10.1006/jcis.1998.5696.
A coated silicon nitride (Si3N4) powder with yttria and alumina precursors as sintering additives was prepared by a heterogeneous precipitation method. The rheological and electrophoretic properties of the suspensions obtained from the coated (CO) powder were investigated and compared with those of pure Si3N4 powder and of the mechanically mixed (MM) powders of Al2O3, Si3N4, and Y2O3. The results showed that the CO powder calcined at 500 degreesC exhibited improved dispersion properties compared with the pure Si3N4 powders. The CO powder possessed the surface character of Al2O3 and Y2O3 particles, that made it easier to process in aqueous media, yielding a higher solid loading than the pure Si3N4 powder. These improvements were attributed to a change in the resultant interaction forces between particles from attractive (pure Si3N4, and MM powders) to repulsive in the case of the CO powder. A homogeneous distribution of sintering additives in the Si3N4 matrix was obtained. Copyright 1998 Academic Press.
采用非均相沉淀法制备了一种以氧化钇和氧化铝前驱体作为烧结添加剂的包覆氮化硅（Si3N4）粉末。研究了由包覆（CO）粉末得到的悬浮液的流变学和电泳性质，并将其与纯Si3N4粉末以及Al2O3、Si3N4和Y2O3的机械混合（MM）粉末的相关性质进行了比较。结果表明，与纯Si3N4粉末相比，在500℃煅烧的CO粉末表现出更好的分散性能。CO粉末具有Al2O3和Y2O3颗粒的表面特性，这使其在水性介质中更易于加工，比纯Si3N4粉末具有更高的固体负载量。这些改进归因于颗粒间相互作用力从吸引（纯Si3N4和MM粉末）转变为排斥（CO粉末）。在Si3N4基体中获得了烧结添加剂的均匀分布。版权所有1998年学术出版社。
