“…2 The combination of nano-confinement and interfacial effects in such nanomultilayered (NML) systems may be exploited to optimize specific material properties, such as mechanical strength, reflectivity, pre-melting or superheating behavior, or corrosion resistance. 3 However, NML architectures are intrinsically thermodynamically unstable and typically exhibit large residual stresses, which may deteriorate their long-term stability under harsh operation conditions (e.g., elevated temperatures, complex loading conditions). 4 NML architectures can be straightforwardly synthesized by Physical Vapor Deposition (PVD) techniques with precise control of, e.g., individual layer thicknesses, modulation periodicity, and chemical composition.…”
The functionality and reliability of nano-multilayered devices and components are largely affected by the stress evolution during fabrication, processing, and operation. The impact of thermal treatment on the stress state and evolving microstructure of Cu/W nano-multilayers, as deposited on different substrates (i.e., Si(001), Al 2 O 3-C, and Al 2 O 3-R) by magnetron sputtering, was investigated by in-situ high temperature X-ray diffraction and high-resolution scanning electron microcopy. The as-deposited Cu and W nanolayers exhibit an out-of-plane orientation relationship according to Cu h111ijj W h110i. On the Al 2 O 3-C and Al 2 O 3-R substrates, the Cu/W nanomultilayers also develop a pronounced in-plane texture given by Cu f111gh10 1ijj W f110gh00 1i. The stress state of the Cu nanolayers in the as-deposited state and upon heating, investigated ex-situ, is largely imposed by the accumulated stresses in the much stiffer W nanolayers. In the as-deposited state, the W nanolayers exhibit a much larger in-plane compressive stress than the Cu nanolayers (i.e., À3.5 GPa versus À1.5 GPa), which both mainly originate from growth stresses generated during the deposition process. The growth stresses in the as-deposited Cu nanolayers are relaxed after annealing at 500 C. Relief of compressive stresses in the W nanolayers is accompanied by grain coarsening which only occurs upon degradation of the nano-multilayered structure. The degradation of the periodic layer structure proceeds in the range of 750 À 900 C and is independent of the substrate.
“…2 The combination of nano-confinement and interfacial effects in such nanomultilayered (NML) systems may be exploited to optimize specific material properties, such as mechanical strength, reflectivity, pre-melting or superheating behavior, or corrosion resistance. 3 However, NML architectures are intrinsically thermodynamically unstable and typically exhibit large residual stresses, which may deteriorate their long-term stability under harsh operation conditions (e.g., elevated temperatures, complex loading conditions). 4 NML architectures can be straightforwardly synthesized by Physical Vapor Deposition (PVD) techniques with precise control of, e.g., individual layer thicknesses, modulation periodicity, and chemical composition.…”
The functionality and reliability of nano-multilayered devices and components are largely affected by the stress evolution during fabrication, processing, and operation. The impact of thermal treatment on the stress state and evolving microstructure of Cu/W nano-multilayers, as deposited on different substrates (i.e., Si(001), Al 2 O 3-C, and Al 2 O 3-R) by magnetron sputtering, was investigated by in-situ high temperature X-ray diffraction and high-resolution scanning electron microcopy. The as-deposited Cu and W nanolayers exhibit an out-of-plane orientation relationship according to Cu h111ijj W h110i. On the Al 2 O 3-C and Al 2 O 3-R substrates, the Cu/W nanomultilayers also develop a pronounced in-plane texture given by Cu f111gh10 1ijj W f110gh00 1i. The stress state of the Cu nanolayers in the as-deposited state and upon heating, investigated ex-situ, is largely imposed by the accumulated stresses in the much stiffer W nanolayers. In the as-deposited state, the W nanolayers exhibit a much larger in-plane compressive stress than the Cu nanolayers (i.e., À3.5 GPa versus À1.5 GPa), which both mainly originate from growth stresses generated during the deposition process. The growth stresses in the as-deposited Cu nanolayers are relaxed after annealing at 500 C. Relief of compressive stresses in the W nanolayers is accompanied by grain coarsening which only occurs upon degradation of the nano-multilayered structure. The degradation of the periodic layer structure proceeds in the range of 750 À 900 C and is independent of the substrate.
The paper estimates corrosion resistance of new multilayer metallic materials with internal protector against pitting. Using an electron microscope method, the mechanism of the layers' corrosive destruction has been experimentally substantiated. The authors have suggested chemical and electrochemical methods of accelerated corrosion tests allowing for determining the corrosion destruction rate. The electrochemical method reveals the limiting stage of the process and allows calculating the mass corrosion index and substantiating the choice of protector for the specific corrosive medium. The chemical method allows for quantitative assessment of the internal protector's effectiveness and for defining the multilayer/monometallic material corrosion resistance ratio.
The paper estimates corrosion resistance of new multilayer metal materials with internal protector, in which the principle of tread pitting-protection is implemented. Experimentally, using the electron-microscopic method, the mechanism of corrosion destruction of layers is substantiated. The electrochemical and chemical methods of accelerated tests are proposed, which make it possible to determine the rate of corrosion destruction. The electrochemical method allows revealing the limiting stage of the process, calculating the mass index of corrosion and justifying the choice of the tread for this corrosive environment. The chemical test method makes it possible to quantify the effectiveness of the action of the inner tread and determine the relative index of corrosion resistance of the multilayer material compared with the monometallic material.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
