摘要
采用非线性加热法煅烧锆、钇的草酸盐前驱体,制备了8%Y2O3(摩尔分数)稳定ZrO2(8YSZ)超细粉末。研究了金属离子与草酸的摩尔比及热处理方法对8YSZ的晶体结构、晶粒大小、形貌、比表面积、粒子团聚的影响。通过改变不同温度范围的加热速度来优化草酸盐前驱体热分解工艺。采用优化前驱体热分解工艺即非线性加热法,于600～700℃煅烧得到的粉末为等轴晶形,粒子大小在90～100nm之间,粒子间仅有较弱的软团聚。煅烧过程晶粒生长动力学的研究表明:当煅烧温度高于700℃时,晶粒生长的质量传输受晶粒扩散过程控制;低于700℃时,晶粒生长的质量传输由表面扩散过程控制。
Ultrafine 8%(mole fraction) yttria-stabilized zirconia (8YSZ) powder was prepared by nonlinear heating of the oxalate precursor of yttrium and zirconium ions. The effects of molar ratio of metal ions to H_2C_2O_4, and thermal decomposition of precursor on the crystal structure, specific surface area, grain size and morphology of 8YSZ powder were studied. The thermal decomposition process of the oxalate precursor was optimized through varying heating rate in different temperature ranges. The powders produced through optimized thermal decomposition process (nonlinear heating method at 600700 ℃), were weakly aggregated and equiaxial, with a narrow particle size distribution of 90100 nm. The kinetic for grain growth during calcination process was investigated. The results show that grain growth is controlled by grain boundary or lattice diffusion with higher activation energy ((192.92) kJ/mol) when temperature is above 700 ℃, or controlled by surface diffusion with lower activation energy (87.38 kJ/mol) when temperature is below 700 ℃.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2004年第11期1833-1838,共6页
The Chinese Journal of Nonferrous Metals
关键词
钇稳定氧化锆
非线性加热法
草酸盐前驱体
晶粒生长
yttria-stabilized zirconia
nonlinear heating method
oxalate precursor
grain growth
