硅溶胶结合Al2O3-SiC-C铁沟浇注料的力学性能研究  

Mechanical properties of silica sol bonded Al_2O_3-SiC-C trough castables

作　　者：魏军从[1] 杨金萍[1] 黄建坤[1] 周如意[1] 涂军波[1] 王义龙 

机构地区：[1]河北联合大学材料科学与工程学院河北省无机非金属材料重点实验室,河北唐山063009 [2]唐山市国亮特殊耐火材料有限公司,河北唐山063009

出　　处：《耐火材料》2013年第3期180-183,共4页Refractories

基　　金：河北省自然科学基金资助项目(E2012401054);河北省唐山市科技计划项目(12110217A)

摘　　要：为了研究硅溶胶结合Al2O3-SiC-C材料的力学性能,以电熔棕刚玉和碳化硅为主要原料,硅溶胶为结合剂,制备了Al2O3-SiC-C铁沟浇注料,研究了其在110、300、500、700、900、1 100、1 300、1 450℃热处理后的常温物理性能和高温(1 400℃)抗折强度,并借助XRD、SEM等进行物相和显微结构分析。结果表明:随着热处理温度的升高,试样常温强度增加,烧后线变化率增大,体积密度先减小后增大,显气孔率先增大后减小,转折温度在700℃;高温抗折强度超过6 MPa。其原因在于:在中低温下,硅溶胶脱水形成—Si—O—Si—凝胶网络结构,保证了浇注料的中低温强度,700℃时因试样大量脱水而使得显气孔率最大,体积密度最小;在高温下,试样中因形成大量纤维状莫来石而为浇注料提供了较高的常温强度和高温强度。Al2O3-SiC-C trough castables were prepared by using brown fused corundum and silicon car- bide as main starting materials and silica sol as binder. The cold physical properties and hot modulus of rupture（i 400 ℃） of the specimens after heat-treating at 110,300,500,700,900,1 100,1 300 and 1 450 ℃, respectively,were investigated. The phase composition and microstructure were characterized by XRD and SEM. The results show that with heat treatment temperature rising, cold strength of the specimen and change in dimensions on heating increase; bulk density first decreases and then increases, apparent po- rosity first increases and then decreases, and the turning temperature is 700 ℃;HMOR exceeds 6 MPa. The mechanism is that silica sol dewaters to form -Si-O-Si- gel net at low and medium temperatures ensu- ring the strength ,and the specimen has the highest apparent porosity and the lowest bulk density at 700 ℃ because of much dehydration;at high temperatures, a large amount of fibrous mullite forms in the speci- men contributing to the high cold strength and hot strength.

关 键 词：氧化铝-碳化硅-碳 铁沟浇注料 硅溶胶 常温强度 高温强度 

分 类 号：TQ175[化学工程—硅酸盐工业]