摘要
研究了半导化 (Ba0 .9Sr0 .1 ) (Ti0 .999Nb0 .0 0 1 )O3 陶瓷晶粒生长的动力学因子 ,采用固相反应法工艺制备该陶瓷样品 ,化学原材料为纯度高于 99%的BaCO3,SrCO3,TiO2 和Nb2 O5 等 ,并用到微量原料Al2 O3 和MnSiO3 以改善陶瓷的电学性能 .同样化学配方的 8种样品在130 0℃中保温时间分别为 1,3,6 ,10 ,30 ,6 0 ,10 0和 30 0min ,以获得晶粒生长不同程度的块状陶瓷 .利用扫描电子显微技术分析发现 ,随着保温时间的延长样品的平均晶粒尺寸变大 .经自动图像处理技术发现 ,晶粒生长的动力学因子不是常数 :在烧结初期大致为 1.5 ,而在烧结后期为 3.5 .这与大多数报道的实验和模拟结果一致 .
The kinetic exponent of grain growth in (Ba0.9Sr0.1)(Ti0.999Nb0.001)O3 ceramics was investigated. The samples of BST ceramics were produced by the conventional ceramic processing, the solid-state reaction method. Raw materials, BaCO3, SrCO3, TiO2 and Nb2O5, are used, with chemical purity of higher than 99% (in mass). In addition, two minor chemicals, Al2O3 and MnSiO3, are incorporated to enhance the electrical properties of resulting ceramics. After weighed according to a required composition, the chemicals are ball-milled with purified water for about 20 h and calcined at 1200°C for 2 h. They are then ground and milled again with polyvinyl alcohol (PVA) solution binder, and spray-dried for the granulation. The dried powders are hydropressed into pellets and sintered at 1300°C for different holding times to obtain bulk ceramics with different degrees of grain growth. It is observed by SEM that the average grain diameter becomes with the increase of soaking time. It is found that the kinetic exponent obtained by an automatic image processing technique is not a constant, about 1.5 at the early stage of grain growth and 3.5 at its later period. This is in good agreement with most of experimental results and simulated results reported.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2001年第2期146-150,共5页
Journal of The Chinese Ceramic Society
基金
香港RGC资助!项目 (97-0 2 35 )
