Materials Innovation Institute , Mekelweg 2, 2628CD, Delft, The Netherlands.
Nano Lett. 2014 Jan 8;14(1):384-9. doi: 10.1021/nl404565j. Epub 2013 Dec 18.
We present a new approach to study the three-dimensional compositional and structural evolution of metal alloys during heat treatments such as commonly used for improving overall material properties. It relies on in situ heating in a high-resolution scanning transmission electron microscope (STEM). The approach is demonstrated using a commercial Al alloy AA2024 at 100-240 °C, showing in unparalleled detail where and how precipitates nucleate, grow, or dissolve. The observed size evolution of individual precipitates enables a separation between nucleation and growth phenomena, necessary for the development of refined growth models. We conclude that the in situ heating STEM approach opens a route to a much faster determination of the interplay between local compositions, heat treatments, microstructure, and mechanical properties of new alloys.
我们提出了一种新的方法来研究金属合金在热处理过程中的三维组成和结构演变，例如通常用于提高整体材料性能的热处理。它依赖于在高分辨率扫描透射电子显微镜（STEM）中进行原位加热。该方法使用商业 Al 合金 AA2024 在 100-240°C 下进行了演示，以无与伦比的细节展示了析出物在哪里以及如何形核、生长或溶解。单个析出物的观察到的尺寸演变可以将形核和生长现象分开，这对于开发精细的生长模型是必要的。我们得出结论，原位加热 STEM 方法为更快地确定新合金的局部成分、热处理、微观结构和力学性能之间的相互作用开辟了一条途径。
