MgO矿化剂对自结合钛酸铝/莫来石复相材料结构和性能的影响

在铝厂污泥,龙岩高岭土和工业二氧化钛合成出的良好稳定性的钛酸铝/莫来石熟料基础上,添加MgO矿化剂进行改性,其能与钛酸铝/莫来石材料形成固溶体,能抑制Al2TiO5的分解,使得钛酸铝/莫来石复相材料在保持低热膨胀系数的同时,较大辐度地提高了材质的机械强度.采用XRD和SEM法表征各试样的晶相和显微结构;各试样中各晶相的含量由用Rietveld Quantification 法确定;测试各试样的性能.从结构与性能分析结果,确定1.5％为MgO的最佳添加量,形成的三个晶相Al2-xMgx+yTi1-yO5-0.5x-y、Al4.59Si1.41O9.70和α-Al2O3分别为68.2％、26.5％和5.3％,对应的抗折强度为45.67 MPa,体积密度为2.95 g/cm3,吸水率为1.81％,气孔率为4.99％,热震后抗折强度保持率为90.0％.

Influence of MgO Additive on Structure and Performance of Self-bonded Aluminium Titanate-Mullite Composites

A small amount of mineralizer MgO was added into Al2TiO5 synthesized from the waste-residue of aluminum profile factory and kaolin to form aluminium titanate-mullite composites.Moreover,through adding MgO mineralizer,Al2-xMgx+yTi1-yO5-0.5x-y and Al4.59Si1.41O9.70 solid solution multiphase material was prepared to effectively inhibit the decomposition of aluminum titanate solid solution and optimize the thermal stability of materials.The crystalline structure and microstructure of each sample were characterized by XRD and SEM methods,and properties of each sample were tested.Results show as follows: the optimal addition amount of MgO mineralizer is 1.5％to obtain aluminium titanate-mullite composites,in which the corresponding content of aluminum titanate,mullite solid solution and α-Al2O3 are 68.2％,26.5％and 5.3％respectively,and flexural strength is 45.67 MPa,bulk density is 2.95 g/cm3,degree of porosity is 4.99％,water absorption rate is 1.81％,and thermal shock maintenance is up to 90.0％.