Drexel University, Department of Materials Science & Engineering, Philadelphia, PA 19104, USA.
Ultramicroscopy. 2010 Mar;110(4):278-84. doi: 10.1016/j.ultramic.2009.11.006. Epub 2009 Dec 23.
A site-specific method for measuring solute segregation at grain boundaries in an Aluminum alloy is presented. A Sigma 7(Sigma 7=38 degrees 111) grain boundary (GB) in an aluminum alloy (Zr, Cu as main alloying elements) was evaluated using site-specific Local Electrode Atom Probe (LEAP). A sample containing a Sigma 7GB was prepared by combining electron backscatter diffraction (EBSD) and focused ion beam (FIB) milling to locate the GB of interest and extract a specimen. Its composition was determined by LEAP, and compared to a general high angle GB (HAGB). Zr was the only alloying element present in the Sigma 7GB, whereas the general HAGB contained both Cu and Zr. This site-specific LEAP method was found to be an accurate method for measuring GB segregation at specific GB misorientations. The method has advantages over other methods of measuring chemistry at GBs, such as spectroscopy, in that GB structure can be assessed in three dimensions.
提出了一种用于测量铝合金晶界溶质偏析的特定晶界方法。使用特定晶界局部电极原子探针（LEAP）对铝合金（Zr、Cu 为主要合金元素）中的 Sigma 7（Sigma 7=38 度 111）晶界（GB）进行了评估。通过电子背散射衍射（EBSD）和聚焦离子束（FIB）铣削相结合，制备了包含 Sigma 7GB 的样品，以定位感兴趣的 GB 并提取样品。通过 LEAP 确定其组成，并与一般高角度 GB（HAGB）进行比较。Sigma 7GB 中仅存在 Zr 一种合金元素，而一般 HAGB 中同时含有 Cu 和 Zr。该特定晶界 LEAP 方法被发现是一种用于测量特定 GB 偏析的 GB 偏析的准确方法。与其他测量 GB 化学性质的方法（如光谱法）相比，该方法具有评估 GB 结构的优势，因为可以在三维空间中进行评估。
