Strength and ductility of gradient structured copper obtained by surface mechanical attrition treatment
Strength and ductility of gradient structured copper obtained by surface mechanical attrition treatment
复制标题
表面机械研磨处理获得的梯度结构铜的强度和延展性
DOI：
10.1016/j.matdes.2016.05.015
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发表时间：
2016-09-05
影响因子：
8.4
通讯作者：
Zhu, Xinkun
中科院分区：
文献类型：
--
作者：
Yin, Zhe;Yang, Xincheng;Zhu, Xinkun
在室温下进行表面机械摩擦处理（SMAT），在块状纯铜试样的表层形成梯度结构（GS），同时具有良好的均匀伸长率和较高的屈服强度。改变SMAT处理时间，可以形成具有不同组分组分的不同梯度结构，从而调整其力学性能。SMAT样品的屈服强度远高于单独GS层和粗粒（CG）基体的总和，表明SMAT样品具有协同强化作用。重复应力松弛试验进行表征移动位错的演变。结果表明，随着拉伸应变的增大，SMAT处理试样的相对可动位错密度先下降后升高。运动位错的演化与应变硬化演化密切相关。这些观察结果为SMAT样品的高强度和良好延展性的优越组合提供了见解。(C) 2016 Elsevier Ltd.版权所有。
By using surface mechanical attrition treatment (SMAT) at room temperature, a gradient structure (GS) is generated in the surface layer of bulk pure copper samples, which exhibits good uniform elongation and high yield strength simultaneously. Changing SMAT processing time leads to different gradient structures with various component fractions and therefore tune their mechanical properties. The yield strength of the SMAT samples is much higher than the sum of standalone GS layer and coarse-grained (CG) matrix, indicating a synergetic strengthening. Repeated stress relaxation tests were performed to characterize the evolution of mobile dislocations. It was found that the relative mobile dislocation density of SMAT processed sample first drops and then increases with increasing tensile strain. The evolution of mobile dislocations correlates well with strain-hardening evolution. These observations provide insight for the superior combination of high strength and good ductility in SMAT samples. (C) 2016 Elsevier Ltd. All rights reserved.