摘要
研究了重结晶碳化硅高温材料的凝胶注模成型。着重讨论了SiC粉体的分散性、悬浮体的流变性、沉降行为以及烧结机理。结果表明 ,选用适量的分散剂TMAH调整浆料pH =11.9附近可制备出固相体积分数高达 70 %的SiC浓悬浮体。沉降实验表明 ,该浓悬浮体中粗细SiC颗粒间能达到均一稳定的分散 ,悬浮粒子不会明显地沉降。凝胶注模成型所得坯体在 2 45 0℃和氩气氛下烧结可获得重结晶碳化硅高温材料 ,其体积密度为 2 .5 2g .cm- 3,对应的抗弯强度为 5 5 .4MPa。
The gel-casting process of high temperature recrystallized silicon carbide was studied in this paper.The dispersivity of SiC powder,the rheological property of the suspension,sedimentation behavior and the sintered mechanism of R-SiC were discussed.The results show that the concentrated SiC suspension with solid volume loading 70vol.% was prepared when the slurry was adjusted to pH=11.9 via addition in a proper amount of dispersants.The sdeimentation results indicate that the coarser SiC particles can be dispersed stably in the high-solid-loading suspension and have no obvious sedimentation.The high temperature R-SiC material with 2.52g.cm -3 bulk density and 55.4MPa flexural strength was obtained by sintering green bodies prepared by gelcasting at tempe rature of 2450℃ in atmosphere of Ar.
出处
《硅酸盐通报》
CAS
CSCD
2002年第4期3-7,15,共6页
Bulletin of the Chinese Ceramic Society
基金
国家 973基金资助项目 (G2 0 0 0 0 672 0 4 - 0 1)
