氧化铬对无水泥刚玉浇注料矿相、显微结构和强度的影响

Effects of Chrome OxiVde on Phase Composition,Microstructure and Strength of Zero Cement Corundum Castables

以电熔白刚玉颗粒及细粉为主要原料,以α-氧化铝微粉和水合氧化铝为结合剂,研究了加入氧化铬对无水泥刚玉基浇注料矿相、显微结构和抗折强度的影响。结果表明:氧化铬1100℃开始向刚玉中固溶,随温度升高固溶程度增加,使浇注料各组分间的结合不断增强,明显提高了浇注料≥1400℃烧后的强度。氧化铬质量含量由0增加到4.0%时,1400℃烧后的热态抗折强度由5.1MPa增大到14.2MPa。1600℃烧后氧化铬通过固相和气相2种传质方式,在刚玉颗粒表面形成环状的固溶带,将刚玉彼此连接在一起,形成了较强的结合。加入质量分数2.0%的氧化铬可使1600℃烧后刚玉基浇注料在1400℃下的热态抗折强度由不含氧化铬的9.7MPa增大到18.6MPa。

Using white fused alumina, ultra-fine alumina, chrome oxide and hydratable alumina as raw materials, the effects of chrome oxide on phase composition, microstructure and modulus of rupture of zero cement corundum castables are investigated. The results show that modulus of rupture of the castables above 1400℃ are improved by the solide solution formed the reaction between chromium oxide and Corundum from 1100℃. Their solid solubility increases with elevation of temperature. The hot modulus of rupture of the＇ castable sample fired at 1400℃ is increased from 5.1MPa to 14.2MPa with increase of chrome oxide amount from 0 to 4.0wt%. The hot modulus of rupture at 1400℃ of the castable sample fired at 1600℃ is raised from 9.7MPa to 18.6MPa by adding 2.0wt% chrome oxide. The corundum particles are well connected by a ring of the solid solution formed by solid and vapor mass transformation on their surface. Finally, the structure of the castable is enforced.