陶瓷辊棒在辊道窑使用过程中晶相结构与性能变化

采用XRD和SEM方法表征不同位置辊棒的晶相结构与显微结构来探讨陶瓷辊棒在实际窑炉使用过程晶相结构和性能变化。采用物理方法表征辊棒的性能。实验结果表明:不同位置辊棒存在莫来石、刚玉、硅酸钙镁三种晶相。莫来石含量是按未使用的(80.8%)→预热带的(78.4%)→烧结带的(73.4%)→冷却带的(71.5%)的顺序降低;刚玉含量按17.7%→19.2%→18%→22.5%的顺序变化;而晶相硅酸钙镁含量按1.5%→2.4%→7.6%→6%的顺序变化;体积密度和使用寿命按上述顺序降低的,而气孔率和吸水率按上述顺序增加的。

Changes of Crystal Structure and Properties of Ceramic Roller Used in Roller Hearth Kiln

The changes of crystal structure and properties of ceramic roller during its application in the roller hearth kiln were studied. The polycrystalline structure and microstructrue of the roller were characterized by XRD and SEM, and the properties by physical operations. It is confirmed that three crystalline phases, i.e. mullite, corundum and calcium magnesium silicate, exist in the ceramic rollers on different positions of the roller hearth kiln. The content of mullite decreased from the initial value of 80.8% (unused) to 78.4% in the preheating zone and to 73.4% in the sintering zone, finally to 71.5% in the cooling zone. Correspondingly, the content of corundum increased from 17.7% to 19.2%, 18% and 22.5%, respectively, and that of calcium magnesium silicate changed from 1.5% to 2.4%, 7.6% and 6%, respectively. The bulk density and service-life were decreased, while the porosity and water absorption were increased according to the above sequence.