SiO_2引入量对高纯Al_2O_3-MgO-CaO系浇注料性能的影响

Effect of SiO_2 Content on the Properties of High Purity Al_2O_3-MgO-CaO Castable

本试验以板状刚玉、烧结镁铝尖晶石以及活性α-Al_2O_3为主要原料,以纯铝酸钙水泥为结合剂,分别外加0wt%、0.25wt%、0.5wt%的熔融石英粉(w(SiO_2)=99.64%)制备了高纯Al_2O_3-MgO-CaO系浇注料。通过改变熔融石英粉的加入量来改变SiO_2的引入量,对试样的相关性能进行了检测,在研究SiO_2引入量对浇注料性能影响的同时,探究利用引入微量SiO_2在高温烧结中产生的熔融液态玻璃相,提高试样的热震稳定性的可行性。结果表明:引入微量的SiO_2对试样性能尤其是高温性能的影响依然显著,SiO_2的引入量在0wt%~0.25wt%时,试样的各项性能较为优异;利用引入微量SiO_2在高温烧结中产生的玻璃相,在缓冲热应力的同时,可以通过促进CA6生长调整其穿插结构,从而提高了材料的抗热震性。

In this experiment, high purity Al2O3-Mg O-Ca O castables were prepared using tabular corundum,sintered spinel and the activity α-Al2O3 as the main raw material,calcium aluminate cement as binder,addition with the fused silica powder（ w（ SiO2） = 99. 64%） with 0 wt%,0. 25 wt% and 0.5 wt%. By changing the amount of fused silica powder to change the amount of SiO2 introduced,the relative properties of the sample were tested. In order to study the effect of SiO2 introduction on the properties of castables, the feasibility of improving the thermal shock stability of molten glass by introducing trace SiO2 in high temperature sintering is also investigated. The results showed that the addition of trace SiO2 on the properties of samples was especially high temperature properties are still significant,introducing the amount of SiO2 in the 0 wt%-0. 25 wt%,the performance of the samples is excellent; By introducing the glass phase produced by high temperature sintering of trace SiO2,the thermal shock resistance of the material can be improved by promoting the growth of CA6 and adjusting its insert structure while buffering the thermal stress.