锆英石加入量对刚玉质浇注料性能的影响

摘要

Corundum based castable specimens were prepared using white fused corundum(5-3,3-1 and ≤ 1 mm),tabular corundum fines(≤0.044 mm),zircon (≤0.074 mm),α-Al2O3 micropowder as starting materials,Secar 71 cement as binder,drying at 110 ℃ for 24 h,and firing at 1 600 ℃ for 3 h.Effects of zircon additions (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 increasing,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 decreasing,the hot modulus of rupture decreases remarkably.The optimum addition of zircon is 6％.%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℃24h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℃3h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％.