铝酸钙水泥结合莫来石-碳化硅浇注料的组成及性能

Compositions and Properties of Calcium Aluminate Cement Bonded Mullite-SiC Castable

采用烧结莫来石、Secar71水泥及SiC为原料,制备了不同水泥和SiC含量的莫来石质浇注料,研究了浇注料的常温物理性能、热导率及热震稳定性,并借助XRD和EDS研究了材料的物相组成和显微结构。结果表明:随着水泥的加入,浇注料110℃24h显气孔率降低、抗折强度逐渐提高;1100℃3h和1400℃3h抗折强度呈现出先增大后逐渐减小的趋势,当水泥量为25%(质量分数,下同)时,浇注料的显气孔率最高,同时抗折强度达到最大值。随着水泥加入量的增多,浇注料的热震稳定性稍有降低,当水泥量超过25%后,浇注料的热震稳定性逐渐恢复;通过加入5%～10%的SiC,浇注料的热震稳定性明显改善。浇注料的性能同其物相组成及显微结构相关。

Using calcined mullite, Secar71 cement and SiC as raw materials,mullite-SiC castables with different content of calcium aluminate cement and SiC were prepared in this study. Their physical properties at room temperature, thermal conductivity and thermal shock resistance were atudied. The mineral compositions and microstructure of the samples were investigated by XRD and EDS analysis as well. The experimental results show that the apparent porosity of castable decreases and rupture strength increases gradually with addition of cement at 110℃ in 24h, When heat-treated .at 1100℃ in 3h and 1400℃ in 3h, rupture strength of castable increases at first and decreases afterwards. When cement content is 25% （by mass）, the apparent porosity and rupture strength of castable grow to the top. With the addition of cement, the thermal shock resistance of, castable drops a little and regaines when cement content is over 25% （by mass）,The thermal shock resistance of castable improves obviously by adding 5% - 10% （by mass）SiC. The properties of mullite-SiC castable are related to its mineral composition and microstructure.