Stress, interfacial effects and mechanical properties of nanoscale multilayered coatings
Stress, interfacial effects and mechanical properties of nanoscale multilayered coatings
复制标题
DOI：
10.1016/j.surfcoat.2007.05.068
复制
发表时间：
2007-12-15
影响因子：
5.4
通讯作者：
Dub, S. N.
中科院分区：
文献类型：
--
作者：
Abadias, G.;Michel, A.;Dub, S. N.
层厚在纳米范围内的多层涂层表现出了原始的机械性能：包括某些弹性系数的显著软化，屈服强度的大幅增加和硬化效应。这种原始性质与这些体系的高界面密度和较小的颗粒尺寸有关。本文第一部分简要介绍了金属/金属、金属/氮化物和氮化物/氮化物纳米多层膜的弹塑性性质。然后给出了在含能粒子生长的PVD薄膜中常见的大压应力的来源，并对存在不同应力源的外延多层膜的情况进行了说明。第二部分重点介绍了三种不同晶体结构和晶格失配组合的Mo/Ni、TiN/Cu和ZrN/W多层膜系统的最新实验结果。将讨论两个问题：Mo/Ni超晶格中界面混合和弹性软化之间的相互依赖关系，以及TiN/Cu和ZrN/NW结合硬材料和软材料的多层膜的力学行为。用双离子束溅射技术在MgO(001)或Al_2O_3(11(2))衬底上外延生长了这些多层膜。利用小角度和大角度X射线衍射仪以及透射电子显微镜对薄膜的微观结构、晶向、界面结构和生长缺陷类型进行了表征。通过布里渊光散射法和纳米压痕硬度法研究了复合材料的弹性性能。对于选定的样品，采用了FIB-TEM组合技术来成像压痕下变形的纳米层状物。(C)2007 Elsevier B.V.保留所有权利。
Multilayer coatings with layer thicknesses in the nanometer range have been shown to exhibit original mechanical properties: these include pronounced softening of some elastic moduli, large increase in yield strength and hardening effect. Such original properties are related to the high interface density and reduced grain sizes associated with these systems. In the first part of this article, the elastic and plastic properties of metal/metal, metal/nitride and nitride/nitride nanoscale multilayers are briefly outlined. The origin of large compressive stress commonly observed in PVD films grown with energetic particles is then presented and illustrations given for the case of epitaxial multilayers for which different stress sources exist. The second part focuses on recent experimental results obtained for three multilayered systems, Mo/Ni, TiN/Cu and ZrN/W, corresponding to different crystal structure and lattice mismatch combinations. Two issues will be addressed: the interdependence between interfacial mixing and elastic softening in Mo/Ni superlattices and the mechanical behaviour of TiN/Cu and ZrN/NW multilayers combining 'hard' and 'soft' materials. These multilayers were grown epitaxially on either MgO (001) or Al2O3( 11 (2) over bar0) substrates by a dual ion beam sputtering technique. Low-angle and high-angle X-ray diffraction experiments as well as Transmission Electron Microscopy observations were used to characterize the microstructure and crystalline orientation, structure of interfaces and type of growth defects. Elastic properties were studied by Brillouin light scattering and hardness values determined from nanoindentation tests. For selected samples, a combined FIB-TEM technique was implemented to image the deformed nanolaminates beneath the indentor. (C) 2007 Elsevier B.V. All rights reserved.