加入氯化钙对刚玉-尖晶石浇注料性能的影响

Effect of calcium chloride addition on properties of corundum spinel castable

以板状刚玉为骨料,电熔白刚玉粉、尖晶石粉、氧化铝微粉等为基质,以纯铝酸钙水泥为结合剂,分别外加0、1%、2%、3%( w )的氯化钙(CaCl 2)制备了刚玉-尖晶石浇注料,并研究CaCl2加入量对浇注料常温物理性能、高温强度、抗热震性和显微结构的影响。结果表明:随CaCl2加入量从0增加到3%( w ),刚玉-尖晶石浇注料于1 500 ℃处理后的常温强度和显气孔率增加,体积密度降低,线变化率先降低后增大,但总体变化不大;而高温抗折强度和抗热震性得到明显改善,这主要归因于所加CaCl2以溶液形式均匀分布在浇注料中,其与Al2O3反应生成了片状CA6,且CA6晶体较小,均匀分布在试样基质中,起增强、增韧作用。

Corundum spinel castable was prepared by using tabular corundum as aggregates,white fused corundum powder,spinel powder and alumina powder as matrix,pure calcium aluminate cement as a binder,extra adding calcium chloride (0,1%,2%,and 3%,by mass).The effects of CaCl2 addition on cold physical properties,hot strength,thermal shock resistance and microstructure of the castable were studied.The results show that,with the increase of CaCl2 addition from 0 to 3%,the cold strength and apparent porosity of the corundum spinel castable fired at 1 500 ℃ increase,the volume density decreases,and the linear change first decreases and then increases,while the overall change is not significant;however,the hot modulus of rupture and thermal shock resistance are obviously improved.This is mainly due to the fact that,CaCl2 which is evenly distributed in the castable in the form of solution,reacts with Al2O3 to form small flake CA6 crystals evenly distributed in the sample matrix strengthening and toughening the material.