首页|Anisotropic growth of nano-precipitates governed by preferred orientation and residual stress in an Al-Zn-Mg-Cu alloy

Anisotropic growth of nano-precipitates governed by preferred orientation and residual stress in an Al-Zn-Mg-Cu alloy

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Through an understanding of diffusion,precise control of the size distribution of nano-precipitates can be essential to developing superior properties in precipitation-strengthened alloys.Although a signifi-cant influence of crystallographic orientation on the diffusion process is known to exist in low-symmetry hexagonal close-packed alloys,such anisotropic diffusion is still unidentified in high-symmetry cubic al-loys.In this work,we reveal the diffusion-controlled coarsening induced anisotropic growth process of nano-precipitates in an Al-Zn-Mg-Cu alloy.Our experimental and theoretical studies demonstrate that with an increase in the residual stress,the diffusion-controlled coarsening rate is slow along the(112)fiber texture in the alloy matrix with smaller grain sizes.As such,we find that the diffusion activation energy will be increased along the preferred orientation with largest residual stress,which leads to a re-duced diffusion-controlled coarsening rate.Specifically,we demonstrate that the increase in the volume fraction of nano-precipitates originates from the rapid grain-boundary controlled coarsening of the grain-boundary precipitates.Based on these results,an underlying microstructural design strategy is proposed,involving the crystallographic orientation,the residual stress and the grain boundaries to manipulate the precipitate size distribution in this class of alloys.

Aluminum alloyPrecipitate coarsening behaviorPreferred orientationDiffusion coefficientResidual stress

Runze Wang、Hongyun Luo、Sujun Wu、Tianshu Zhao、Xin Wang、Robert O.Ritchie

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School of Materials Science and Engineering,Beihang University,Beijing 100191,China

Key Laboratory of Aerospace Materials and Performance,Beihang University,Beijing 100191,China

Beijing Key Laboratory of Advanced Nuclear Materials and Physics,Beihang University,Beijing 100191,China

Beijing Advanced Innovation Centre for Biomedical Engineering,Beihang University,Beijing 100191,China

Surface Engineering Institution,AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China

Department of Materials Science and Engineering,University of California,Berkeley,CA 94720,USA

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National Key Research and Development Program of ChinaNational Science and Technology Major Projects of China

2017YFF0210002J2019-Ⅶ-0015-0155

2024

材料科学技术(英文版)
中国金属学会 中国材料研究学会 中国科学院金属研究所

材料科学技术(英文版)

CSTPCD
影响因子:0.657
ISSN:1005-0302
年,卷(期):2024.188(21)
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