硅溶胶对莫来石微球质隔热耐火材料性能的影响

Effect of Silica Sol on the Properties of Mullite Microsphere Insulating Refractories

以轻质莫来石微球为主要原料,以Al_2O_3微粉为添加剂,在实验室研制了硅溶胶结合的莫来石质耐火材料,并分析了硅溶胶添加量对其力学性能、热学性能和显微结构的影响。结果表明:经1450℃×3 h处理后的试样,随着硅溶胶加入量的增加,结构更加致密、显气孔率下降、烧后冷态强度上升、线变化率由收缩变为膨胀、1400℃下耐压强度增加、导热系数上升,其中硅溶胶添加量为8%时,可制得各项性能最佳的隔热耐火材料。

Porous lightweight mullite thermal insulation materials were prepared by silica sol bounding process using mullite microspheres as the main raw material and Al2O3 powder was added as additive.The influence of content of silica sol on the density,strength,thermal insulation properties,and microstructure was evaluated.The results show that after heat treatment at 1450℃×3 h,as the content of silica sol increase,the density of the samples increase and the significant porosity decrease,and the cold compressive strength and flexural strength show an increasing trend.The linear change turn from shrinkage to expansion,and the hot compressive stress increase,and thermal conductivity increase at 1400℃.The integrated properties perform best while added 8wt% silica sol.