沉淀法制备氧化铝的相变过程  

Phase transformation of alumina prepared by precipation method

作　　者：李长青[1] 武万良[1] 王树成[1] 徐成彦[2] 

机构地区：[1]黑龙江科技学院材料科学与工程学院,哈尔滨150027 [2]哈尔滨工业大学材料科学与工程学院,哈尔滨150001

出　　处：《黑龙江科技学院学报》2009年第6期427-430,共4页Journal of Heilongjiang Institute of Science and Technology

基　　金：黑龙江省教育厅科学技术研究项目(11513099)

摘　　要：为获得沉淀法制备氧化铝的相变过程及微观形貌,将NaOH溶液与AlCl3溶液混合,在pH值6～9内,制备三羟铝石,将其加热到1 200℃获得了氧化铝粉体。经TG-DTA、XRD、FTIR光谱、SEM等测试手段分析,300℃煅烧后获得了单水铝石,然后依次获得γ-Al2O3、δ-Al2O3、θ-Al2O3过渡相,并且在1200℃煅烧后获得了纯相α-Al2O3。TG-DTA表征,粉体在273℃脱水显著,在1000℃后θ-Al2O3向α-Al2O3形核并长大,需要较大激化能而放热,1 200℃煅烧后FTIR透过光谱表征α-Al2O3的典型的AlO6八面体结构引发形成640～590 cm^-1的两个吸收峰。制备的三羟铝石呈亚微米的团絮状,而纯相α-Al2O3呈现亚微米的聚集体颗粒形貌。这为改进陶瓷性能提供工艺参数依据。To obtain the phase transformations and morphologies of alumina by precipation method, bayerite is synthesized by AlCl3 solution mixed by NaOH solution within pH value 6 -9, and alumina is prepared after 1 200 ℃ heat treatment. By TG - DTA, XRD, FTIR spectra and SEM method characterizing, boehmite is synthesized after 300 ℃ heat treatment, and γ-Al2O3, δ-Al2O3, θ-Al2O3 transition phases are obtained accordingly, and pure α-Al2O3 is prepared after 1 200 ℃ heat treatment. As-prepared powder dehydrates serious at 273 ℃ characterrized by TG- DTA, and θ-Al2O3 transforms into α-Al2O3 phase by nucleation and growth process, large activation energy is required and exothermic reaction is significant, two absorption bands are shown at 640 -590 cm- 1 due to AlO6 octahedron in classical α-Al2O3 structure by transmission FTIR spectra after 1 200 ℃ heat treatment. Bayerite as-prepared is conglomerated and pure α-Al2O3 is conglomerated structure.

关 键 词：氧化铝 TG-DTA 过渡相 FTIR光谱 三羟铝石 

分 类 号：TF124[冶金工程—粉末冶金]