Ying X R, Du Y X, Song M, Lu N, Ye H Q
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016, China.
Senior High Section, Northeast Yucai School, 41 Century Road, Hunnan New District, Shenyang, 110179, China.
Micron. 2016 Nov;90:18-22. doi: 10.1016/j.micron.2016.07.010. Epub 2016 Aug 20.
Precipitates and their associated strain fields significantly influence mechanical properties and, consequently, the industrial performance of aluminum alloys. In this work, we present a direct measurement of strains induced by η' and η precipitates in an Al-Zn-Mg-Cu alloy using aberration-corrected high-resolution transmission electron microscopy and quantitative strain analysis. The results demonstrate that the strain induced by precipitates in the Al-Zn-Mg-Cu alloy shows significant tensile strains perpendicular to the longitudinal direction of the precipitate discs on the side of the discs and along the longitudinal direction at both ends of the η' and η precipitates. This strain field can be described by an equivalent dislocation model, in which the lattice mismatch between the precipitate and the matrix is equivalent to a series of dislocation pairs along the precipitate/matrix interfaces.
析出相及其相关的应变场对铝合金的力学性能以及工业性能有着显著影响。在本研究中，我们利用像差校正高分辨率透射电子显微镜和定量应变分析，直接测量了Al-Zn-Mg-Cu合金中η'和η析出相所引起的应变。结果表明，Al-Zn-Mg-Cu合金中析出相所引起的应变在析出圆盘侧面垂直于圆盘纵向方向呈现出显著的拉伸应变，并且在η'和η析出相两端沿纵向方向也存在拉伸应变。这种应变场可以用一个等效位错模型来描述，其中析出相和基体之间的晶格失配等效于沿着析出相/基体界面的一系列位错对。
