Singh A K, Imam M A, Sadananda K
Naval Research Laboratory, Washington, DC 20375-5000.
J Electron Microsc Tech. 1988 Apr;8(4):355-61. doi: 10.1002/jemt.1060080404.
Ion milling is commonly used to prepare specimens for observation under transmission electron microscope (TEM). This technique sometimes introduces artifacts in specimens contributing to misleading interpretation of TEM results as observed in the present investigation of Al-Li-Cu alloys. This type of alloy, in general, contains several kinds of precipitates, namely delta', T1, and theta'. It is found that ion milling even for a short time produces drastic changes in the precipitate characteristics as compared to standard electropolishing methods of specimen preparation for TEM. Careful analysis of selected area diffraction patterns and micrographs shows that after ion milling delta' precipitates are very irregular, whereas other precipitates coarsen and they are surrounded by misfit dislocations. In situ hot-stage TEM experiments were performed to relate the microstructure to that observed in the ion-milled specimen. Results and causes of ion milling effects on the microstructure are discussed in relation to standard electropolishing techniques and in situ hot-stage experiment.
离子铣削常用于制备用于透射电子显微镜（TEM）观察的样品。在本次对Al-Li-Cu合金的研究中发现，这种技术有时会在样品中引入伪像，导致对TEM结果的错误解读。一般来说，这类合金包含几种析出相，即δ'、T1和θ'。结果发现，与用于TEM样品制备的标准电解抛光方法相比，即使短时间的离子铣削也会使析出相特征发生剧烈变化。对选区衍射花样和显微照片的仔细分析表明，离子铣削后，δ'析出相非常不规则，而其他析出相则粗化，并且被失配位错所包围。进行了原位热台TEM实验，以将微观结构与离子铣削样品中观察到的结构相关联。结合标准电解抛光技术和原位热台实验，讨论了离子铣削对微观结构影响的结果及原因。
