Influence of synthesis temperatures on the crystalline grain growth and morphology of lanthanum magnesium hexaaluminate  

作　　者：Junbin Sun Jinshuang Wang Wenzhi Huang Yu Hui Xin Zhou Lifen Li Jianing Jiang Longhui Deng Yunya Niu Shujuan Dong Xueqiang Cao 

机构地区：[1]State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology [2]Science and Technology on Advanced Ceramic Fibers and Composites Laboratory, National University of Defense Technology [3]Atmospheric Environment Research Center, Shenyang Academy of Environmental Sciences

出　　处：《Journal of Rare Earths》2017年第12期1226-1232,共7页稀土学报（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(51501137);National University of Defense Technology,and Wuhan University of Technology

摘　　要：Lanthanum magnesium hexaaluminate（LaMgAl（11）O（19）, LMA） was prepared at different temperatures by solid-state reaction. Phase compositions and crystal morphologies of specimens synthesized at different temperatures were investigated using X-ray diffraction（XRD）, scanning electron microscopy（SEM）. It was observed that the crystalline grain size of LMA was not only dependent on the preparation temperature but also on its powder morphology. In the temperature range of 1300 e1550℃, LMA showed platelet grain and the average crystalline grain size increases with the increase in temperature. At1600℃, if the powder was sintered for two times, the equiaxed grain could be found with the decrease in grain space, resulting in the reduction of the crystalline grain size. Styles of specimens（powder or disk） might have no obvious influence on morphologies and sizes of LMA crystalline grains which were synthesized with the well-dispersed raw material mixtures. The synthesis temperature played a key role in influencing the free space for the formation and growth of crystalline grains.Lanthanum magnesium hexaaluminate（LaMgAl（11）O（19）, LMA） was prepared at different temperatures by solid-state reaction. Phase compositions and crystal morphologies of specimens synthesized at different temperatures were investigated using X-ray diffraction（XRD）, scanning electron microscopy（SEM）. It was observed that the crystalline grain size of LMA was not only dependent on the preparation temperature but also on its powder morphology. In the temperature range of 1300 e1550℃, LMA showed platelet grain and the average crystalline grain size increases with the increase in temperature. At1600℃, if the powder was sintered for two times, the equiaxed grain could be found with the decrease in grain space, resulting in the reduction of the crystalline grain size. Styles of specimens（powder or disk） might have no obvious influence on morphologies and sizes of LMA crystalline grains which were synthesized with the well-dispersed raw material mixtures. The synthesis temperature played a key role in influencing the free space for the formation and growth of crystalline grains.

关 键 词：Hexaaluminate Crystalline grain growth Crystal morphology 

分 类 号：O782[理学—晶体学] TG174.4[金属学及工艺—金属表面处理]