A Surface Transition Layer Model for Size Effect in T2 Copper Micro-Compression-猫眼课题宝

T2铜微压缩尺寸效应的表面过渡层模型

DOI：

10.3390/met9070736

发表时间：

2019-06

期刊：

METALS

影响因子：

2.9

通讯作者：

中科院分区：

材料科学3区

文献类型：

作者：

Deng Lei;Liu Wei;Wang Xinyun;Jin Junsong

通过铜微柱室温压缩实验，研究了试样尺寸和晶粒尺寸对变形试样表面形貌和流变应力的影响。SEM结果表明，当晶粒尺寸增大或试样尺寸减小时，试样自由表面的变形不均匀性增大。同时，应力-应变曲线显示，在压缩过程中，试样的流变应力也随着晶粒尺寸的增大或试样尺寸的减小而减小。根据纳米压痕实验结果，在面层模型的基础上，考虑晶粒相互约束和过渡层晶粒的存在，建立了表面过渡层模型。实验结果表明，与表面层模型相比，表面层模型计算的应力-应变曲线能更准确地反映材料的实际变形情况。

The effects of sample size and grain size on the surface morphology and flow stress of deformed samples were investigated by means of copper micro-cylinder compression experiments at room temperature. The results of SEM showed that when the grain size increased or the sample size decreased, the deformation non-uniformity of samples’ free surfaces increased. Meanwhile, the stress–strain curves showed that during the compression process, the flow stress of the sample also tended to decrease as the grain size increased or the sample size decreased. According to the experimental results of nanoindentation, a surface transition layer model was established on the basis of the surface layer model by considering the mutual constraint of grains and the existence of transition layer grains. The experimental results indicated that the stress–strain curve calculated by the surface transition layer model can more accurately reflect the actual deformation situation of the material compared to the surface layer model.