EBSD技术在大塑性变形制备超细晶与纳米材料中的应用:试样制备、参数优化与数据分析

摘要

With the help of FESEM,high resolution electron backscatter diffraction can investigate the grains/subgrains as small as a few tens of nanometers with a good angular resolution (～0.5°).Fast development of EBSD speed (up to 1100 patterns per second)contributes that the number of published articles related to EBSD has been increasing sharply year by year.This paper reviews the sample preparation,parameters optimization and analysis of EBSD technique,emphasizing on the investigation of ultrafine grained and nanostructured matcrials processed by severe plastic deformation (SPD).Detailed and practical parameters of the electropolishing,silica polishing and ion milling have been summarized.It is shown that ion milling is a real universal and promising polishing method for EBSD preparation of almost all materials.There exists a maximum value of indexed points as a function of step size.The optimum step size depends on the magnification and the board resolution/electronic step size.Grains/subgrains and texture,and grain boundary structure are readily obtained by EBSD.Strain and stored energy may be analyzed by EBSD.%在场发射扫描电镜的帮助下,电子背散射技术(EBSD)能用来研究大小低达几(十)纳米的晶粒(或亚晶粒),其角分辨率达～0.5°.EBSD技术的快速发展(电子衍射花样的采集速度已高达1100点/s)使其相关领域的科技论文发表数量迅速增加.本文评述了EBSD的试样制备、参数优化和数据分析,特别是在大塑性变形(SPD)制备超细晶和纳米材料方面的应用.总结了电化学抛光、二氧化硅乳液机械抛光和离子束抛光等EBSD试样制备技术的优缺点和实用参数.结果表明,离子束抛光技术是一项通用的、几乎适用于所有EBSD试样的有效抛光方法.随着EBSD扫描步长的变化,花样的标定率存在一个极大值.最优化的EBSD扫描步长取决于试样图片的放大倍数和数据采集板的分辨率(或电子步长).对晶粒和亚晶粒、织构和晶界结构等进行分析是EBSD的基本功能.EBSD也可对塑性变形的应变和存储能等进行分析.