摘要
采用固相法制备了不同钙含量的铬酸镧试样。用扫描电镜分析了试样的微观组织 ,研究了钙含量及烧结时间对晶粒尺寸、收缩率及电阻率的影响。发现晶粒均为等轴晶 ,以台阶生长方式长大 ,随烧结时间的延长出现台阶退化现象。使用 2 0 0 0h后La0 .0 2 Ca0 .98CrO3晶粒极为致密 ,气孔聚集在晶内及晶界。钙含量的摩尔分数从 0 0 2到 0 10变化时 ,试样收缩率明显增加 ,电阻率明显下降。随烧结时间的延长 ,试样的室温电阻率变化不大。
The samples of LaCrO_3 with different Ca content were prepared by solid reaction method,and the microstructure was observed by SEM.The influence of Ca content and the sintering time of LaCrO_3 to the grain size,shrinkage ratio and electrical resistivity was studied.It was found that the LaCrO_3,grains composed of equiaxed grains,grow in stage which degenerates with increasing the time.The density of La_(0.02)Ca_(0.98)CrO_3 is very high being used for 2000h,and there are pores in grains and on grain boundary.With the Ca content increasing from 0.02 to 0.1,the shrinkage ratio of the sample increases and the electrical resistivity decreases obviously.With increasing the sintering time,the change of the electrical resistivity is not obvious.
出处
《金属热处理》
CAS
CSCD
北大核心
2003年第12期8-12,共5页
Heat Treatment of Metals
基金
国家"十五"
"86 3"(2 0 0 1AA32 70 10 )项目
山东省中青年科学家基金 (0 2BS0 6 1)
