| 段保华,张柯,刘平.纯铜表面纳米化的微观结构演化及其力学性能研究[J].有色金属材料与工程,2019,40(4):19-27. |
| 纯铜表面纳米化的微观结构演化及其力学性能研究 |
| Study on Microstructure Evolution and Mechanical Properties of Surface Nanocrystallization of Pure Copper |
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| DOI：10.13258/j.cnki.nmme.2019.04.04 |
| 中文关键词: 表面机械滚压处理 纯铜 梯度纳米结构 微观结构演化 |
| 英文关键词:surface mechanical rolling process pure copper gradient nanostructure microstructure evolution |
| 基金项目:国家重点研发计划资助项目（2017YFB0306405） |
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| 摘要点击次数: 1830 |
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| 中文摘要: |
| 利用表面机械滚压处理（surface mechanical rolling treatment，SMRT）工艺在纯铜表面制备出梯度纳米结构层，获得了最表层为取向随机的纳米晶粒、亚表层的晶粒尺寸在厚度方向上呈梯度分布的结构层。采用光学显微镜、扫描电子显微镜、透射电子显微镜对微观组织进行表征，研究了晶界、位错、孪晶界等微观结构的演化。通过改变SMART工艺参数，在纯铜表面制备出不同厚度的梯度纳米结构层，对比分析了梯度纳米结构层厚度对纯铜力学性能的影响。结果表明：经SMRT后，试样距表面大约5 μm处的显微硬度高达1.56 GPa，其横截面的硬度随着距表面深度增加呈递减趋势；相比于粗晶铜，SMRT后纯铜的屈服强度提高了2倍多，而塑性损失很少，并且SMRT后纯铜的屈服强度随着梯度纳米结构层厚度的增加而提高。 |
| 英文摘要: |
| Gradient nanostructured layers were successfully prepared on pure copper surface by surface mechanical rolling process (SMRT), and randomly oriented nano-grains were achieved on the topmost surface layer of the specimens. Meanwhile, the grain size of sub-surface layer was gradient distribution along the thickness direction. Microstructure was characterized by optical microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The evolution of microstructures such as grain boundary, dislocation and twin boundary was studied. Gradient nanostructured layers with different thickness were successfully prepared on the pure copper surface by different mechanical rolling processes. The effects of the thickness of gradient nanostructured layers on mechanical properties were compared and analyzed. The results show that the microhardness reaches a maximum value of 1.56 GPa at the topmost surface and decreases gradually to the matrix value. Compared with coarse crystal copper, the yield strength of pure copper after SMRT was increased by more than 2 times with little plastic loss, and is increased with the increase of the thickness of gradient nanostructure layer after SMRT. |
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