摘要
以纯铝酸钙水泥为结合剂，研究纳米碳酸钙的加入量对刚玉质浇注料性能和显微结构的影响。结果表明，添加的纳米碳酸钙在热处理后与基质中的氧化铝反应形成片状的六铝酸钙，影响了浇注料的性能；随着纳米碳酸钙加入量的增加，在110℃热处理后浇注料的显气孔率和体积密度变化不大，耐压强度和抗折强度都略有增大，而在1000、1500、1600℃热处理后，浇注料显气孔率均逐渐增大，相应的体积密度均逐渐减小，耐压强度和抗折强度均逐渐降低。纳米碳酸钙的加入量能提高试样的强度保持率，但热震后试样的强度均明显降低；浇注料经1000～20℃一次水冷后强度保持率逐渐提高，热震性能有所改善；XRD和SEM分析结果表明，在高温热处理过程中纳米碳酸钙与刚玉反应形成片状的六铝酸钙，对结构产生不利影响，从而导致在高温热处理后，随着纳米碳酸钙加入量的增加，浇注料的显气孔率逐渐上升，强度逐渐降低。
Effect of nano-calcium carbonate addition on the properties and microstructure of corundum castable was investigated. The results show that： the platelet calcium hexaluminate （CA6） formed from the reaction of nano-calcium carbonate and alumina in the matrix after thermal treatment affects the properties of the castable. After thermal treatment at 110 ℃, with the increase of the nano-calcium carbonate content, the apparent porosity and bulk density have no obvious change and the cold crushing strength （CCS） and modulus of rupture in bending （MOR） have increased a bit. However, after thermal treatment at 1 000, 1 500 and 1 600 ℃, the apparent porosity increases gradually while the bulk density, CCS and MOR decrease simultaneously. The addition of nano-calcium carbonate can improve the ratio of residual strength of the specimens, but the strength of the specimens decreases obviously after the thermal shock test. The ratio of residual strength of the castable increases gradually after one-time water cooling from 1 000 ℃ to 20 ℃ and the thermal shock resistance also improves. XRD and SEM indicate that the platelet CA6 formed from the reaction of nano-calcium carbonate and alumina in the process of thermal treatment brings damage to the structure of the corundum castable. therefore after thermal treatment, with the increase of nano-calcium carbonate content, the apparent porosity of the castable increases while the strength decreases gradually.
出处
《武汉科技大学学报》
CAS
2009年第2期188-192,共5页
Journal of Wuhan University of Science and Technology
关键词
纳米碳酸钙
六铝酸钙
刚玉质浇注料
物理性能
显微结构
nano-calcium carbonate
calcium hexaluminate
corundum castable
physical property
microstructure
