Enhanced age hardening response and precipitation evolution of elastic stress aged Mg–Zn alloys
Enhanced age hardening response and precipitation evolution of elastic stress aged Mg–Zn alloys
复制标题
弹性应力时效镁锌合金的增强时效硬化响应和析出演化
DOI：
10.1016/j.jallcom.2020.158513
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发表时间：
2021-04
影响因子：
6.2
通讯作者：
Zhenyi Huang
中科院分区：
文献类型：
--
作者：
Yongjian Wang;Liping Zhong;Yuchen Dou;Zhenyi Huang
如何经济有效地改善镁合金的时效硬化性能是一个重要而有趣的问题。研究了Mg-Zn合金在有无弹性应力作用下的时效硬化响应和析出相演变规律。无应力时效试样的显微组织观察表明，硬度低的主要原因是β 1′相的数密度较低且长径比相对较小，而在应力时效初期，α-Mg基体中出现大量纳米级强化β 1′相。在相同的峰时效阶段，应力时效试样中β 1′相的长径比明显高于无应力时效试样。应力作用下产生的大量位错作为析出相的形核位置和溶质的快速扩散通道，是导致硬度显著提高和动力学增强的主要原因。在有应力和无应力的两种样品中均观察到无硅酸盐区（PFZ）。在应力时效样品中，PFZ的形成主要受位错运动的控制，这与无应力样品中的溶质空位耗尽机制不同。结果表明，外加应力在减小尺寸、增加密度和促进沉淀动力学方面与常用方法具有相似的作用，但对沉淀演变的应力取向效应可以忽略不计。
How to improve the age hardening response of Mg alloys in economical and effective ways is an important and interesting issue. The age hardening response and precipitation evolution of Mg–Zn alloys with and without external elastic stress are investigated. Microstructural observations of stress-free aged samples show that the low hardness is mainly due to the low number density and relatively small aspect ratio of β 1′ precipitates, while a large number of nano-scale strengthening β 1′ precipitates appear in the α-Mg matrix at the early stage of stress aging. In addition, the aspect ratio of β 1′ precipitates in the stress aged samples is evidently higher than that of the stress-free aged samples at the same peak aged stage. Abundant dislocations introduced by the applied stress act as nucleation sites of precipitates and rapid diffusion path of solutes, which are mainly responsible for the remarkable increment in hardness and promoted kinetics. Precipitate-free zones (PFZs) are observed in both samples with and without stress. In the stress aged samples, the formation of PFZs is mainly controlled by the motion of dislocations, which is different from the solute-vacancy depletion mechanism in the stress-free samples. Results imply that the external stress plays a similar role to that of commonly used methods in reducing the size, increasing the density, and promoting the precipitation kinetics, but has a negligible stress-orienting effect on the precipitate evolution.
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DOI：
10.1007/bf02668000
发表时间：
1973-06
期刊：
Metallurgical Transactions
影响因子：
--
作者：
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通讯作者：
M. Abe;K. Asano;A. Fujiwara
影响因子：
9.4
作者：
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影响因子：
6
作者：
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影响因子：
6
作者：
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DOI：
10.1016/j.msea.2013.09.045
发表时间：
2013-12
影响因子：
6.4
作者：
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通讯作者：
Y. Lin;Yu-Qiang Jiang;Xiao-Min Chen;D. Wen;Hua-Min Zhou