钛酸铝热分解的结晶形貌  

Crystal morphology of aluminium titanate thermal decomposition

作　　者：高振昕[1] Gao Zhenxin

机构地区：[1]中钢集团洛阳耐火材料研究院有限公司

出　　处：《耐火材料》2019年第6期401-404,共4页Refractories

摘　　要：以化学纯Al(OH)3和试剂级TiO2为原料,按Al2TiO5的化学计量组成将混合好的粉料在钢模中压制成Φ10 mm×15 mm的试样,于大气条件下以1600℃保温3 h烧结合成钛酸铝(AT);然后将烧结试样于大气条件下分别进行1300℃保温3 h和1000℃保温100 h的热处理,并利用XRD和FESEM-EDS鉴定AT热处理前后的显微结构。结果表明:1600℃保温3 h合成的钛酸铝晶体形貌呈不规则粒状,尺寸约20μm,其晶间和晶内形成5~10μm气孔。烧结合成钛酸铝经1300℃保温3 h热处理后,钛酸铝的晶体形貌不变,只是晶间微裂纹稍许扩展,而宏观结构几乎未变;经1000℃保温100 h热处理时,钛酸铝分解成晶粒尺寸小于5μm的刚玉和小于10μm的金红石。EDS分析表明,刚玉可固溶3.9%(w)的TiO 2,而金红石只固溶0.3%(w)的Al2O3。The aluminium titanate specimens were prepared using Al(OH)3 in chemically pure and TiO2 in reagent grade as raw materials,mixing according to the stoichiometry of Al 2TiO 5,pressing in a steel die into cylindrical bars with dimensions of Φ10 mm×15 mm,and sintering at 1600℃in air condition for 3 h.Then the sintered specimens were heat treated in air condition at 1300℃for 3 h and 1000℃for 100 h,respectively.The microstructure of the aluminium titanate before and after heat treatment was characterized by XRD and FESEM-EDS.The results show that the crystal morphology of aluminium titanate heat treated at 1600℃for 3 h is irregular grain with size of about 20μm,and there are pores formed in crystals and among crystals with size of 5-10μm.For the sintered aluminium titanate treated at 1300℃for 3 h,the crystal morphology doesn’t change,but the microcracks among crystals expand a little,whereas the macroscopic form is almost unchanged.When heat treated at 1000℃for 100 h,the aluminium titanate decomposes to corundum with size less than 5μm and rutile with size less than 10μm.The EDS analysis shows that the corundum may solid dissolve 3.9 mass%TiO2,but rutile can only solid dissolve 0.3 mass%Al 2O3.

关 键 词：钛酸铝(AT) 热分解 固溶 显微结构 

分 类 号：TQ175[化学工程—硅酸盐工业]