结合相对氧化物结合SiC窑具结构和性能的影响  

Effects of bonding phases on properties of oxides bonded SiC kiln furniture

作　　者：刘小团[1] 尹洪峰[1] 任耘[1] 张军战[1] 袁志丽[1] 马啸尘[1] 

机构地区：[1]西安建筑科技大学材料科学与工程学院,西安710055

出　　处：《耐火材料》2008年第1期47-50,共4页Refractories

基　　金：陕西省教育厅产业化培育资助项目(02JC31)

摘　　要：以45％（质量分数，下同）的SiC（0．5～1．43mm）和20％的SiC（≤0．5mm）为骨料，基质中固定SiC细粉的含量为20％，根据不同的结合相（粘土、SiO2和莫来石）和Si粉变化基质组成。物料混匀后，压制成型为125mm×25mm×25mm（20MPa）和636mm×36mm（12MPa）的试样，干燥后于1450℃保温3h制备了SiC窑具，同时又分别在1400℃、1450℃和1500℃保温3h分别制备了SiO2结合、粘土结合和莫来石结合的SiC窑具。对试样的显气孔率、体积密度、常温抗折强度、高温抗折强度、热震后和氧化＋热震后的抗折强度进行了检测，并借助XRD和SEM研究了材料的物相组成和显微结构。结果表明：（1）SiO2微粉因粒度细，表面积大，活性高，高温下能促进窑具的烧结，其结合的窑具的综合性能优于另外两种结合；（2）SiO2结合SiC窑具在1400℃烧成时的综合性能较好；（3）添加剂Si粉由于防止了SiC氧化和促进了烧结，使粘土结合SiC窑具性能得以改善。SiC kiln furniture bonded by clay, SiO2 and mullite respectively were prepared with 45% SiC （0.5 - 1.43 mm） and 20% SiC （ ≤0.5 mm） as aggregates,changing the matrix compositions according to the bond- ing phases （clay, SiO2 and mullite） and Si powder but fixing the content of SiC powder in the matrix at 20% ,pressing into the specimens with the size of 125 mm x 25 mm x 25 mm and Ф36 mm x 36 mm at 20 MPa and 12 MPa respectively,drying,and then firing at 1 450 ℃ for 3 h. Apparent porosity,bulk density, CMOR, HMOR,modulus of rupture after thermal shock,and modulus of rupture after oxidation and thermal shock were tested. Phase composition and microstructure were analyzed by XRD and SEM. The results show that. （1）SIO2 micropowder can improve the sintering of kiln furniture because of small particle size, high specific surface areas and high activity,so SiO2 bonded SiC kiln furniture is superior to SiC kiln furni-ture bonded by clay or mullite. （2）SiO2 bonded SiC kiln furniture fired at 1400 ℃ has better properties. （3） Additive Si powder improves the properties of clay bonded SiC kiln furniture because of preventing the oxidation of SiC and promoting the sintering.

关 键 词：碳化硅窑具 二氧化硅微粉 结合相 

分 类 号：TQ175.1[化学工程—硅酸盐工业] TQ174.758