In order to improve the volume stability and thermal shock resistance of the light weight mullite-corundum castables,the spherical light weight mullite aggregate (≤1,1-2 and 3-4 mm),tabular corundum powder (≤0.074 mm),Guangxi white clay (≤0.045 mm),Secar 71 cement (≤0.088 mm) and kyanite (≤0.5 mm) were used as starting materials to investigate the effect of kyanite content (0,4%,6%,8%,10% and 12%) on the properties and microstructure of the castables.The results show that with the increase of the kyanite content,the specimens fired at 1 500 ℃ change from shrinkage to expansion significantly,the bulk density decreases,the apparent porosity increases,the cold strengths decrease,the micro-pore (≤10 μm) content decreases and the macro-pore content and size increase in the matrix,and the thermal shock resistance gets better firstly and then worse.The specimen contained 6% of kyanite has the best comprehensive properties,a bulk density of 1.96 g·cm-3,an apparent porosity of 37.1%,a flexural strength of 10.8 MPa,a high crushing strength of 43.8 MPa,a low linear change of 0.07%,an elastic modulus residual rate of 42.9%,and a thermal conductivity of 0.60 W·(m·K)-1 at 800 ℃.%为了改善含球形莫来石轻骨料的轻质莫来石-刚玉浇注料的体积稳定性及抗热震性,以球形莫来石轻骨料(≤1、1~2和3~4 mm)、板状刚玉细粉(≤0.074 mm)、广西白泥(≤0.045 mm)、Secar 71水泥(≤0.088 mm)和蓝晶石(≤0.5 mm)为主要原料,研究了蓝晶石含量(加入质量分数分别为0、4%、6%、8%、10%和12%)对轻质莫来石-刚玉浇注料显微结构与性能的影响.结果表明:经1 500 ℃热处理后,随着蓝晶石含量增加,试样由显著收缩变为显著膨胀,体积密度减小,显气孔率增大,常温强度降低;基质中小气孔含量(≤10 μm)逐渐减小,大气孔孔径及含量逐渐增大;抗热震性先变好后变差.综合考虑各项性能,蓝晶石含量为6%(w)试样的综合性能最佳:体积密度为1.96 g·cm-3,显气孔率为37.1%,常温抗折强度为10.8 MPa,常温耐压强度为43.8 MPa,加热永久线变化率为0.07%,弹性模量保持率为42.9%,800 ℃热导率为0.60 W·(m·K)-1.
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