锆英石加入量对刚玉质浇注料性能的影响

Effect of zircon addition on properties of corundum based castables

以电熔白刚玉(5～3、3～1、≤1 mm)、板状刚玉细粉(≤0.044 mm)、锆英石(≤0.074 mm)、α-Al2O3微粉为主要原料,以Secar 71水泥为结合剂,制备了刚玉质浇注料,经110℃24 h烘干和1 600℃3 h烧后,研究了锆英石加入量(质量分数分别为0、3%、6%、9%)对试样性能、物相组成和显微结构的影响。结果表明:随着锆英石加入量的增加,试样经110℃24 h烘干后的体积密度先增大后减小,显气孔率先减小后增大,常温抗折强度变化不大;试样经1 600℃3 h烧后的体积密度、常温抗折强度和抗热震性呈先增大后减小的趋势,高温抗折强度呈明显下降趋势。综合各项性能,认为锆英石的最佳加入质量分数为6%。

Corundum based castable specimens were prepared using white fused corundum（5-3,3-1 and ≤1 mm） ,tabular corundum fines（≤0. 044 mm） ,zircon（ ≤. 074 mm） ,α-Al2O3 micropowder as starting mate- rials,Secar 71 cement as binder,drying at 110 ℃ for 24 h,and firing at 1 600 ℃ for 3 h. Effects of zircon addi- tions（0,3% ,6% and 9% ,in mass） on property,phase composition and microstructure of the specimens were studied. The results show that：with zircon addition increasing,the bulk density of specimens dried at 110 ℃ for 24 h changes from increasing to decreasing,the apparent porosity changes from decreasing to increas- ing ,and the cold modulus of rupture does not show remarkable difference. The bulk density,cold modulus of rupture and thermal shock resistance of specimens fired at 1 600 ℃ for 3 h change from increasing to de- creasing ,the hot modulus of rupture decreases remarkably. The optimum addition of zircon is 6%.