Hartshorne Matthew I, Isheim Dieter, Seidman David N, Taheri Mitra L
Department of Materials Science and Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104, USA.
Department of Materials Science and Engineering, Northwestern University, 2220 Campus Drive, Evanston, IL 60208-3108, USA; Northwestern University Center for Atom-Probe Tomography, 2220 Campus Drive, Evanston, IL 60208-3108, USA.
Ultramicroscopy. 2014 Dec;147:25-32. doi: 10.1016/j.ultramic.2014.05.005. Epub 2014 Jun 12.
Atom-probe tomography (APT) provides atomic-scale spatial and compositional resolution that is ideally suited for the analysis of grain boundaries. The small sample volume analyzed in APT presents, however, a challenge for capturing mesoscale features, such as grain boundaries. A new site-specific method utilizing transmission electron microscopy (TEM) for the precise selection and isolation of mesoscale microstructural features in a focused-ion-beam (FIB) microscope lift-out sample, from below the original surface of the bulk sample, for targeted preparation of an APT microtip by FIB-SEM microscopy is presented. This methodology is demonstrated for the targeted extraction of a prior austenite grain boundary in a martensitic steel alloy; it can, however, be easily applied to other mesoscale features, such as heterophase interfaces, precipitates, and the tips of cracks.
原子探针断层扫描（APT）提供了原子尺度的空间和成分分辨率，非常适合用于晶界分析。然而，APT分析的小样本体积对于捕捉中尺度特征（如晶界）来说是一个挑战。本文提出了一种新的特定位置方法，该方法利用透射电子显微镜（TEM）在聚焦离子束（FIB）显微镜取出样品中，从块状样品的原始表面下方精确选择和分离中尺度微观结构特征，以便通过FIB-SEM显微镜有针对性地制备APT微尖。该方法已在马氏体钢合金中针对先前奥氏体晶界的靶向提取得到了验证；然而，它可以很容易地应用于其他中尺度特征，如异相界面、析出物和裂纹尖端。
