烧成温度对Al2TiO5-ZrO2复合材料性能的影响  

Effect of firing temperature on properties of Al_2TiO_5-ZrO_2 composite materials

作　　者：朱宝利[1] 王瑞生[2] 范增为[2] 王志发[2] 卜景龙[2] 王榕林[2] 孙加林[1] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]河北理工大学无机非金属材料河北省重点实验室

出　　处：《耐火材料》2008年第6期432-436,共5页Refractories

基　　金：国家自然科学基金委员会资助项目(50572023);河北省教育厅资助项目(2006116)

摘　　要：首先以平均粒径为6μm的预合成Al2TiO5为初始原料,分散在Zr4+浓度为0.06 mol·L-1的氧氯化锆溶液中,以氨水为沉淀剂,将液相共沉淀形成的前驱体经650℃焙烧1 h,制得纳米ZrO2含量(w)分别为2%、5%、8%的Al2TiO5-ZrO2复合粉体;然后在复合粉体中加入6%聚乙烯醇(PVA)结合剂,以100 MPa压力制成53 mm×10 mm×10 mm试样,110℃干燥2 h后,经1 350、1 400、1 450、1 500℃保温2 h烧成制备了Al2TiO5-ZrO2复合材料。对烧后试样的显气孔率、抗折强度、热膨胀率进行了分析测定,借助XRD、SEM分析了Al2TiO5粉体物相组成及烧后部分试样的物相组成和显微结构,并研究了烧成温度对不同ZrO2含量试样的烧结性能、热膨胀性能、抗热震性能与显微结构的影响。结果表明:随着烧成温度的提高和ZrO2含量的增加,显气孔率与抗折强度呈现不规则的变化趋势,此种情况与预合成Al2TiO5粉磨后微粉的物相变化有关;烧成温度为1 500℃时,ZrO2含量为2%的试样,在1 250℃的热膨胀率为0.16%,显微结构致密,抗热震性能好。Pre-synthesized Al2TiO5（d50 =6μm） as starting material was dispersed in zirconium oxychloride solution （Zr^4＋ concentration：0.06 mol·L^-1）. Then aqueous ammonia was used as precipitating agent to obtain zir-conia-aluminium titanate composite powder precursors by co-precipitation process. The precursors were fired at 650℃ for 1 h, producing Al2Ti5-ZrO2 composite powders with ZrO2 contents of 2% ,5% and 8%. The composite powders adding 6% polyvinyl alcohol （PVA） as the binder were pressed into 53 mm×10 mm×10mm bars under 100MPa. After drying at 110℃ for 2 h,the Al2TiO5-ZrO2 composite specimens were fired at 1350,1400,1450 and 1500℃ for 2 h, respectively. The apparent porosity, MOR and thermal expansion rate of the fired specimens were analyzed;the phase compositions of the aluminium titanate powders and the phase compositions and microstructure of the fired specimens were analyzed by XRD and SEM. The effects of firing temperature on the firing properties,thermal expansion,thermal shock resistance and microstructure of the specimens with different ZrO2 contents were studied. The experimental results showed that the apparent porosity and MOR of Al2TiO5-ZrO2 composite specimens changed irregularly as firing temperature and ZrO2 content increased, attributing to the phase transformation of Al2TiO5 powder after milling. The specimen with 2wt% ZrO2 fired at 1500℃ had a dense structure with the thermal expansion rate of 0.16% at 1250℃ and its thermal shock resistance and microstructure was apparently better than those of the others.

关 键 词：烧成温度 纳米氧化锆 钛酸铝 共沉淀法 

分 类 号：TQ326.5[化学工程—合成树脂塑料工业] TQ174.758