Effect of pre-aging and Al addition on age-hardening and microstructure in Mg-6 wt% Zn alloys
Effect of pre-aging and Al addition on age-hardening and microstructure in Mg-6 wt% Zn alloys
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DOI：
10.1016/j.msea.2008.06.005
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发表时间：
2008-11-25
期刊：
影响因子：
6.4
通讯作者：
Shin, K. S.
中科院分区：
文献类型：
--
作者：
Oh-ishi, K.;Hono, K.;Shin, K. S.
采用硬度测试、透射电子显微镜（TEM）和三维原子探针研究了Mg-Zn和Mg-Zn- al合金的时效硬化响应和显微组织变化。采用铸造后热挤压法制备试样。与单步时效相比，两步时效试样在早期表现出增强的时效硬化反应。TEM观察表明，峰时效Mg-Zn样品有两种析出物：一种是沿基体相c轴的棒状析出物；另一个是在基面上的一个盘子。Mg-Zn-Al样品有棒状和立方相析出。两步时效后，Mg-Zn和Mg-Zn- al合金的组织都变得更加精细。峰时效Mg-Zn合金中以棒状析出物为主，而Mg-Zn- al合金中以棒状析出物和立方相为主。对70℃预时效样品的原子探针分析清楚地表明富锌带的形成。(C) 2008 Elsevier B.V.版权所有
The age-hardening response and microstructural variation Mg-Zn and Mg-Zn-Al alloys were examined by hardness test, transmission electron microscopy (TEM) and three-dimensional atom probe. The samples were prepared by hot-extrusion after casting. The two-step aged samples exhibit enhanced age-hardening response at an earlier stage compared to the single-aged ones. TEM observations exhibited that the peak aged Mg-Zn samples had two kinds of precipitates: one was a rod along the c-axis of the matrix phase; the other was a plate lying on the basal plane. The Mg-Zn-Al samples had rods and cuboidal precipitates. After two-step aging, the microstructure becomes finer for both the Mg-Zn and Mg-Zn-Al alloys. The rodlike precipitates were dominant in the peak aged Mg-Zn alloy, while the comparable number of rods and cuboidal precipitates were present in the Mg-Zn-Al alloy. Atom probe analyses for the samples pre-aged at 70 degrees C clearly showed the formation of Zn-rich zones. (C) 2008 Elsevier B.V. All rights reserved.