纳米固体材料的显微结构  

Microstructure in Nanocrystalline Materials

作　　者：李斗星[1] 平德海[1] 黄建宇[1] 吴玉琨[1] 叶恒强[1] 

机构地区：[1]中国科学院金属研究所固体原子像开放研究实验室

出　　处：《电子显微学报》1997年第3期255-260,共6页Journal of Chinese Electron Microscopy Society

摘　　要：本文综述了利用高分辨电子显微术研究以三种不同工艺制备的纳米固体材料显微结构的结果。用惰性气体凝聚加压法、机械合金化及非晶晶化法制备的纳米晶样品中，多数晶界呈有序结构，但存在程度不等的点阵畸变，在前两种方法制备的样品中，还存在局部无序的晶界区域。晶界的有序程度依次为：非晶晶化法＞惰性气体凝聚加压法＞机械合金化法。用前两种方法制备的样品中还观察到大量的、室温下不常见的形变孪晶。在不同工艺制备的三种样品中，缺陷密度的高低依次为：机械合金化法＞惰性气体凝聚加压法＞非晶晶化法。对于非固溶二元体系，凝聚加压法较难形成明显的亚稳晶体相。This paper reports the experimental results of HREM studies on the microstructure of nanocrystalline materials prepared by three different methods.According to the synthesized methods,the ordered degree of grain boundary structure is as follows:amorphous crystallization>inert gas condensation>mechanical alloying.Most of grain boundaries in nanocrystalline materials prepared by the three methods are similar to the grain boundaries in coarse grained materials.However,disordered structure and nanovoids are observed in the samples prepared by inert gas condensation and mechanical alloying.Defect structures in nanocrystalline materials are also investigated,and the density of defect structure is as follows:mechanical alloying>inert gas condensation>amorphous crystallization.As for the immisble system,the inert gas condensation method is difficult to synthesis a supersaturated solution alloy,but a supersaturated solid solution can be obtained in Fe Cu system by mechanical alloying.

关 键 词：纳米固体材料 显微结构 高分辨 电子显微术 

分 类 号：O48[理学—固体物理] TN16[理学—物理]