Y_2O_3-MgO-Al_2O_3烧结助剂对SiC陶瓷烧结和导热性能的影响  

Effects of Y_2O_3-MgO-Al_2O_3 additives on the densification and thermal conductivity of the silicon carbide ceramic

作　　者：戴斌[1] 郜玉含[1] 周洪庆[1] 

机构地区：[1]南京工业大学材料科学与工程学院,江苏南京210009

出　　处：《电子元件与材料》2013年第5期1-5,共5页Electronic Components And Materials

基　　金：江苏高校优势学科建设工程资助项目;长江学者和创新团队发展计划资助项目(No.IRT1146)

摘　　要：对SiC粉体进行热处理，采用Y2O3-MgO-Al2O3烧结助剂，在1750～1950℃下30MPa热压烧结1h，制备SiC陶瓷。TG分析SiC的氧化特性，测定Zeta-电位研究SiC粉体的分散特性，测定其高温浸润性研究烧结助剂与SiC之间的亲和性。结果表明：SiC粉体热处理和提高SiC浆体的pH值，有利于提高Zeta．电位，进而提高分散均匀性；Y2O3-MgO-Al2O3烧结助剂高温下与SiC具有良好的浸润性；SiC粉体热处理明显降低了烧结温度。尽管Y2O3-MgO-Al2O3烧结助荆在高温下有一定的挥发，但是当其含量大于等于9％（质量分数）时，1800-1950℃下热压烧结可获得显气孔率小于等于0．19％的致密SiC陶瓷，其热导率大于190W·m^-1·K^-1。By preheating SiC powder, using Y2O3-MgO-Al2O3 as additive and hot-pressed sintering at 1700-1 950 ℃ and 30 MPa, for 1 h, SiC ceramics were prepared. The dispersion, wettability and oxidation behavior of the SiC powder were measured by Zeta-potential, wetting angle at a relatively high temperature, and TG respectively. As a result, the rising of Zeta-potential of SiC powder and the improvement of dispersion are contributed by preheating and increasing pH value. The wettability between additive and SiC is excellent at a relatively high temperature. The preheating process of SiC makes the sintering temperature decline dramatically. When the content of the additives is equal to or higher than 9% （mass fraction）, although there is some volatilization when Y2O3-MgO-Al2O3 additives at a relatively high temperature, the SiC ceramics which apparent porosity are only 0.19% and thermal conductivity is 190 W ·m^-1·K^-1 can still be obtained by hot-pressed sintering at 1 800-1 950℃.

关 键 词：SIC陶瓷 热压烧结 烧结助剂 热导率 Zeta-电位 显气孔率 

分 类 号：TQ173[化学工程—搪瓷工业]