摘要
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(≤0.088mm)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(≤10μm)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)。
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 micropore ( ≤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 ℃.
出处
《耐火材料》
北大核心
2017年第4期246-249,255,共5页
Refractories
基金
湖北省自然科学基金重点资助项目(2015CFA122)
武汉市青年科技晨光计划项目(2016070204010108)
关键词
球形莫来石轻骨料
蓝晶石含量
莫来石-刚玉浇注料
显微结构
抗热震性
spherical light weight mullite aggregates
kyanite content
mullite- corundum castables
micro- structure
thermal shock resistance