nl404565j_si_008.avi (4.02 MB)
Real-Time Atomic Scale Imaging of Nanostructural Evolution in Aluminum Alloys
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posted on 2014-01-08, 00:00 authored by Sairam
K. Malladi, Qiang Xu, Marijn A. van Huis, Frans
D. Tichelaar, K. Joost Batenburg, Emrah Yücelen, Beata Dubiel, Aleksandra Czyrska-Filemonowicz, Henny W. ZandbergenWe
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.