结合剂对氧化铝-碳化硅-碳质铁沟浇注料力学性能和显微结构的影响  

Influence of Binders on Microstructure and Mechanical Properties of Al_2O_3-SiC-C Iron Trough Castables

作　　者：魏军从[1] 黄建坤[1] 王义龙 高春辉[1] 涂军波[1] 

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,唐山063009 [2]唐山市国亮特殊耐火材料有限公司,唐山063009

出　　处：《硅酸盐通报》2013年第6期1057-1062,共6页Bulletin of the Chinese Ceramic Society

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

摘　　要：分别以水泥、氧化镁-硅灰和硅溶胶三种结合剂制备了氧化铝-碳化硅-碳铁沟浇注料,借助相关测试标准和SEM、EDS、XRD等测试手段对比研究了三种浇注料的力学性能、显微结构和物相组成。研究结果表明:以水泥和硅溶胶结合的浇注料常温强度较大,以氧化镁-硅灰为结合剂的浇注料常温强度最小;硅溶胶为结合剂浇注料高温抗折强度最大,氧化镁-硅灰为结合剂最小。原因在于:尽管以水泥和硅溶胶为结合剂的浇注料在高温烧成时都生成莫来石,但以水泥结合试样中只是在基质中部分生成莫来石晶体,而以硅溶胶为结合剂试样由于硅溶胶分散性好,脱水后微粒活性更高,在试样中均匀生成了大量交错分布的莫来石晶体,且长径比更大,因此显著提高了高温抗折强度;以氧化镁-硅灰为结合剂的浇注料高温生成镁铝尖晶石、镁橄榄石和堇青石,由于镁铝尖晶石促进了碳化硅的氧化,使得结构疏松,强度降低。Different Al2O3-SiC-C castables for blast furnace iron trough were prepared by using cement,MgO-silica micropowder and silica sol as binders respectively.Mechanical properties were determined according to relevant test standards.Microstructure and phase compositions of three castables were characterized by means of SEM,EDS and XRD.The results showed that cold strengths of cement or silica sol bonded castables were bigger than that of MgO-silica micropowder bonded castables;The hot modulus of rupture of the castables combined with silica sol was highest,while that of MgO-silica micropowder bonded was least.This is because even though cement or silica sol bonded castables both produced mullite crystals at high temperature,only some mullite crystals were partly produced in the matrix of cement bonded system.Large amount of interweaved fibrous mullite with big length-diameter ratio generated in silica sol bonded castables due to good dispersibility and high activity of small silica particles after dehydration,which could enhance hot modulus of rupture considerably.MgO-silica micropowder bonded castables produced magnesium aluminate spinel,forsterite and cordierite at high temperature.Magnesium aluminate spinel could contribute to the oxidation of silicon carbide and lead to a loose structure and a lower strength.

关 键 词：氧化铝-碳化硅-碳 铁沟浇注料 结合剂 力学性能 显微结构 

分 类 号：TQ175[化学工程—硅酸盐工业]