摘要
通过对Cu/Ni多层膜纳米压痕过程的二维分子动力学模拟,研究了失配位错对多层膜力学性能的影响。结果表明,失配位错网对滑移位错的阻碍作用使Cu/Ni多层膜得以强化,并且这种强化作用依赖于多层膜的调制波长(相邻两膜层的厚度之和)。当调制波长大于临界值λc时,失配位错的应力场随膜层厚度变化不大;当调制波长小于临界值λc时,失配位错的运动导致了界面处的应力集中,从而使多层膜的力学性能下降。为了优化多层膜的力学性能,临界调制波长要大于在单膜层内产生位错的深度。
The nanoindentation on Cu-Ni thin films was simulated by using 2D molecular dynamics simulations (MDS), and the effects of the misfit dislocations on the mechanical properties of the multilayers was examined. The misfit dislocation network plays an important role in strength enhancement of Cu/Ni multilayers because of its resistant to glide dislocations. But the strengthening relies on the wavelength, which was defined as the thickness of adjacent two layers in multilayers. When the wavelength was bigger than the critical value λc, the stress field of misfit dislocation was independent on the wavelength. When the wavelength was less than the critical value λc, the stress concentration caused by the movement of misfit dislocations will weaken Cu/Ni multilayers. And the critical wavelength should be bigger than the depth where dislocation nucleates in the inner part of one layer.
出处
《功能材料》
EI
CAS
CSCD
北大核心
2005年第6期918-920,926,共4页
Journal of Functional Materials
基金
国家自然科学基金资助项目(50071014)
交通部博士学位资助项目(200232522504)
关键词
多层膜
失配位错
分子动力学
纳米压痕
Coatings
Copper
Mechanical properties
Molecular dynamics
Multilayers
Nickel
Strengthening (metal)
Stress concentration
