均一大孔径刚玉-莫来石多孔陶瓷的制备与研究

Preparation and Research of Corundum-mullite Homogeneous Macroporous Ceramics

为了获得抗热震性好的工业窑炉用高温隔热材料,研究以山铝α-Al2O3、石英、苏州土为主要原料,聚苯乙烯球为成孔剂,制备了具有均一球形大孔径的刚玉-莫来石多孔陶瓷。测试了样品的气孔率、吸水率、体积密度及抗压强度,采用XRD、体视显微镜、SEM等测试方法研究了样品的相组成、显微结构。结果表明,所有样品经1400℃烧成后吸水率、气孔率达到最低值,抗压强度达到最大值,配方中含氧化铝最多的样品抗压强度最大达17MPa。从体视显微镜观测可知,样品中球形大气孔均匀地独立分布,孔径为0.7~1.3mm。XRD和SEM分析表明,只有配方中石英含量少于20%的样品经1500℃烧成后,其主晶相为刚玉、莫来石。晶粒分布均匀且粒径大小一致的样品,刚玉、莫来石含量越高其抗热震性能越好。

In order to prepare high temperature insulation material for industrial kiln with good thermal shock resistance, corundum-mullite porous ceramics with uniform spherical large pore size were prepared.Theα-Al2O3,quartz and Suzhou Clay were used as the main raw materials,besides polystyrene spheres were used as pore-forming agent.The porosity, water absorption,bulk density and compressive strength of the samples were measured.The phase compositions and micro-structure of samples were studied by different test methods.The experimental results show that all the samples after fired at 1 400℃present lower water absorption,porosity and higher compressive strength,the compressive strength of the sample with the largest content of alumina in the formulation is the highest,and the compressive strength is 17 MPa.The large spherical pores are evenly distributed,and the pore size is 0.7~1.3mm.The main crystalline phases of samples fired at 1 500℃are corundum and mullite only when the content of quartz in the formula is less than 20%.When samples have uniform grain distribution and similar particle size,the higher the contents of corundum and mullite,the better the thermal shock resistance of the samples.