(西安交通大学 金属材料强度国家重点实验室，西安 710049)
摘 要: 采用磁控溅射方法分别在聚酰亚胺基体以及单晶硅基体上制备恒定调制比(η)以及恒定调制周期(λ)的Cu-Cr纳米金属多层膜；通过单轴拉伸试验以及纳米压痕试验系统研究Cu-Cr多层膜屈服强度及硬度的尺度依赖性。微观分析结果表明：基体对多层膜的微观结构无影响，Cu-Cr多层膜在生长方向上均呈现Kurdjumov-Sachs取向关系，即{111}Cu//{110}Cr和á110ñCu//á111ñCr。力学测试结果表明：调制比恒定的Cu-Cr多层膜的屈服强度及硬度随调制周期的缩短而增加；调制周期恒定的Cu-Cr多层膜的屈服强度/硬度随调制比的增加而增加。Cu-Cr多层膜变形机制在临界调制周期(λc≈25 nm)和临界调制比(ηc ≈1)由Cu层内单根位错滑移转变为负载效应。
关键字: 纳米金属多层膜；强度；硬度；调制周期；调制比
（ZHANG Jin-yu, NIU Jia-jia, ZHANG Xin, LEI Shi-ying, ZHANG Peng, LIU Gang, SUN Jun）
Abstract:Polyimide-supported and silicon-supported Cu-Cr nanostructured metallic multilayers with constant modulation ratio (η) and constant modulation period (λ) were respectively synthesized by means of direct current (DC) magnetron sputtering. The size-dependent yield strength and hardness of Cu-Cr multilayers were respectively investigated by uniaxial tensile test and nanoindentation test. It is revealed from the microstructure analysis that the substrates have no influence on the microstructure of Cu-Cr multilayers, and that the layers are textured in the growth direction with the Kurdjumov-Sachs orientation relationship, i.e., {111}Cu//{110}Cr and á110ñCu//á111ñCr. The mechanical test results show that both the yield strength and hardness of Cu-Cr multilayers with constant η increase with reducing λ, while those of the ones with constant λ increase with increasing η. The deformation mechanism of Cu-Cr nanostructured metallic multilayers transit from the slide of single dislocation confined to individual Cu layers to the load bearing effect at a critical modulation period λc (≈25 nm) or a critical modulation ratio ηc ( ≈1).
Key words: nanostructured metallic multilayers; strength; hardness; modulation period; modulation ratio
