Muon kinetics in heat treated Al (–Mg)(–Si) alloys
Muon kinetics in heat treated Al (–Mg)(–Si) alloys
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热处理 Al (-Mg)(-Si) 合金中的 μ 子动力学
DOI：
10.1016/j.actamat.2013.06.050
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发表时间：
2013
期刊：
影响因子：
9.4
通讯作者：
Randi Holmestad
中科院分区：
文献类型：
--
作者：
Sigurd Wenner;Katsuhiko Nishimura;Kenji Matsuda;Teiichiro Matsuzaki;Dai Tomono;Francis L. Pratt,Calin D. Marioara;Randi Holmestad
Al-Mg-Si 合金可进行热处理，并依靠沉淀硬化来提高机械强度。我们采用μ子自旋弛豫技术来进一步了解该系统中复杂的沉淀序列。材料中的 μ 介子捕获动力学揭示了原子尺寸缺陷的存在，例如溶质原子（Mg 和 Si）和空位。通过比较纯 Al、Al-Mg、Al-Si 和 Al-Mg-Si 在不同温度下的 μ 子动力学，我们建立了基于不同类型缺陷的 μ 子捕获峰的解释。 Al-Mg-Si 样品在 200 K 左右的温度下有一个独特的 μ 介子捕获峰。对于在 70-150 °C 退火的样品来说，该峰最高，这些样品的微观结构以高密度簇/吉尼尔-普雷斯顿区为主。 μ子捕获可以通过这些结构内部存在的空位来解释。当团簇在老化过程中转变成更发达的沉淀物时，空位就会从材料中消失。
Al–Mg–Si alloys are heat-treatable and rely on precipitation hardening for their mechanical strength. We have employed the technique of muon spin relaxation to further our understanding of the complex precipitation sequence in this system. The muon trapping kinetics in a material reveals a presence of atom-sized defects, such as solute atoms (Mg and Si) and vacancies. By comparing the muon kinetics in pure Al, Al–Mg, Al–Si and Al–Mg–Si when held at different temperatures, we establish an interpretation of muon trapping peaks based on different types of defects. Al–Mg–Si samples have a unique muon trapping peak at temperatures around 200 K. This peak is highest for samples that have been annealed at 70–150 °C, which have microstructures dominated by a high density of clusters/Guinier–Preston zones. The muon trapping is explained by the presence in vacancies inside these structures. The vacancies disappear from the material when the clusters transform into more developed precipitates during aging.