Formation Of Metal Layer Research Articles

INFLUENCE OF METAL LAYER SURFACED WITH LOCAL ADDITION OF AMPLIFER ON THE STRESSED AND DEFORMED STATE OF THE PLATE

One of the important aspects of the surfacing process, both restorative and strengthening, is the formation of metal layers that differ significantly in physical and mechanical properties from the base. At the same time, the local action of a concentrated heat source causes uneven heating of the workpiece in thickness, and the crystallization of the deposited layer is accompanied by casting shrinkage and structural transformations, the stress-deformed state of such objects will be quite unfavorable both from the point of view of forming and the subsequent operation of the finished products. In view of this, based on the methods of the theory of elasticity, develop an algorithm for analytically determining the stress-strain state of a welded plate of considerable width as a composite two-layer material under the influence of external normal loading, taking into account the location of zones of increased hardness in the form of strips in the welded layer. The surfaced prismatic plate was adopted as a two-layer structure, in which the deformations of the material are directly proportional to the stresses. The deposited layer is continuous. The thickness of the plate and the deposited layer are unchanged. By using the dependences of the stress-strain state indicators on one stress function, a mathematical model of the welded plate as a two-layer structure was formed. An algorithm for determining the deformations and distribution of stresses in the plate under the condition of its flat deformation in the direction of surfacing is constructed. The periodic change of the modulus of elasticity of the deposited layer is taken into account. The indicators of the stress-strain state of the plate from its normal load were determined. The effect of Poisson's ratio on the layer-by-layer distribution of stresses in the plate is shown.

Estimation of the electrodes sputtering of the miniature linear accelerator

In this paper, electrode sputtering of the miniature linear accelerator (MLA)is investigated. The main part of this study is numerical simulations of the deposited metal layers formation on the insulator. It consist of three parts: ion beam trajectory analysis in MLA using COMSOL Multiphysics, simulations of surface sputtering by BCA codes (SRIM, SDTrimSP, and SCATTER) and sputtered particles trajectory analysis in MLA using COMSOL Multiphysics. The main sources of deposited particles are identified using numerical simulations of the surface sputtering by the ions extracted from the Penning ion source (PIS) and charge-exchange neutrals originated inside the ion-optical system (IOS) and subsequent analysis of the sputtered particle trajectories. Experimental data were obtained by digitizing MLA photos during operation by ImageJ software. Simulations of the electrodes sputtering of MLA were performed. The simulations allowed to determine the erosion zones responsible for the deposited metal layer formation on the insulator surface. The experimental data are in good qualitative agreement with the simulated ones.

Effects of annealing following back contact metal layer formation on CZTS solar cell properties

Cu2ZnSnS4 (CZTS) is interesting as a light absorption layer for thin-film solar cells because it consists of only earth-abundant materials such as copper, zinc, tin, and sulfur. The poor adhesion between CZTS and molybdenum (Mo), which is the back metal contact material, causes CZTS to peeling off during the chemical bath deposition (CBD) for the formation of CdS as a buffer layer. This induces severe degradation of the solar cell performance. In this study, we investigated the effect of annealing following back contact metal layer formation on CZTS stability and solar cell performance. By annealing Mo/soda lime glass at 400 °C in atmosphere, Mo was oxidized, and the surface roughness of Mo increased. On the Mo surface, the CZTS peeling off was suppressed during the CBD process, resulting in an improvement in the shunt resistance.

Direct Formation of Metal Layer on Anion Exchange Membrane Using Electroless Deposition Process

Direct Formation of Metal Layer on Anion Exchange Membrane Using Electroless Deposition Process

THE PROCESS OF FORMATION OF RAILWAY WHEEL DAMAGES AND TIRES IN OPERATION

Purpose. The dependence analysis of structural changes in the metal of railway wheels and tires from indicated influences in operation, for the further development of strategy of service reliability growth. Methodology. Test materials are the details selected from railway wheels which were taken out of operation beforehand because of various damages. Micro-structural researches were made with the use of light microscope Epiquant and electron microscope. The sizing of structural elements was done by using the methods of quantitative metallography. Findings. Over the past few decades the rapid development of industry was supported by the steady growth of intensity of using railway transport. In this case simultaneous increase of load at wheel set axle, with the increase of speed was accompanied by natural increase of the amount of cases of premature wheels and tires’ withdrawing out of operation. Railway wheel, except the formation of metal layer at rolling surface with the high defects concentration of crystal structure and first of all dislocations, falls under thermal influence from interaction with break blocks. The nature of joint influence (cold deformation and heating) on the metal rim of a wheel is conditioned by the appearance of sufficiently high gradients of structural changes that can be considered as the influence on the level of internal residual stresses. In case of the rise of volume part of carbide phase at a constant ferrite grain size, it is achieved only by the increasing of dislocation nucleation sources without changing the number of annihilation positions. In this case the accumulation of dislocations at the initial stages of plastic deformation (in metal volume in front of delta arm crack) will lead to the formation of cementite globes around certain interlocked dislocation density. In contrast the sharp increase of deformation hardening carbon steel parameters is observed. Originality. During the braking of locomotive the speed rise of metal heating at rolling surface is provided with the increase of temperatures that is enough for the beginning of phase transformations. Under the further cooling there is the formation of a number of structures formed from sliding to diffusive mechanisms. As a result the chosen areas become the centers of future metal deformations on wheels’ rolling surface and tires. Practical value. Based on the study of patterns of damages’ formation in railway wheels and tires from the peculiarities of internal metal structure and the working conditions «Classifier of defects» was developed а nd «Technical tips for determination of causes of cracks in solid-rolled railway wheels and destruction in general», which have been implemented on Ukrzaliznytsia.

Investigation into the processes of atom redistribution encountered during of the formation of metal layers on the surface of aluminum gallium nitride

The results of an investigation into the properties of double-layer metal contacts to the epitaxial layers of AlxGa1-xN solid solutions for ultraviolet photodetectors and UHF electronic devices are presented. The processes of atom redistribution during the formation of metal layers and their subsequent annealing to form low resistance contacts were studied by Auger electron spectroscopy. The results obtained allowed us to develop a technique for creating ohmic contacts having low resistance value.

Formation and Control of Ultrasharp Metal/Molecule Interfaces by Controlled Immobilization of Size‐Selected Metal Nanoclusters onto Organic Molecular Films

The formation of metallic layers on ultrathin molecular films via a well‐controlled interface is essential for constructing organic nanodevices composed of metal/molecule/metal sandwich junctions. The scanning tunneling microscopy and spectroscopy studies demonstrate that an ultrasharp metal/molecule interface is realizable by depositing size‐selected Ag nanoclusters (Agn) from the gas phase on few‐layer films of C60 molecules. It is also demonstrated that Agn nanoclusters can be immobilized on monolayer films of oligothiophene molecules via C60 molecules, although they three‐dimensionally aggregate on bare oligothiophene films. It is also shown that electrons and holes are injected into the topmost layer of C60 films via the Agn/C60 interface. Moreover, the barrier height for carrier injection at the Agn/C60 interface can be modified depending on the size of Agn nanoclusters and the kinetic energy during the deposition. The present results demonstrate that the controlled immobilization of metallic nanoclusters on molecular films can be used as a fabrication technology for metal/molecule/metal junctions.

Radio frequency sputtered Al:ZnO-Ag transparent conductor: A plasmonic nanostructure with enhanced optical and electrical properties

Optimization of metal-based transparent conductors (MTCs) made of silver and aluminium-doped zinc oxide (AZO) prepared by radio-frequency (r.f.) sputtering has been carried out through tuning of metal film properties. The influence of morphology and related plasmonic features of AZO/Ag/AZO MTCs on their optical and electrical performance is demonstrated and it is shown that the nominal thickness of the silver layer itself is not the most crucial value determining the MTC performance. The MTC performance has been optimized by a search of deposition conditions ensuring fractal-type metal layer formation up to a certain coalescence state that enables full gaining from silver optical properties, including its plasmonic features. For 150 W- and 200 W-deposited silver, MTCs with maximum transmittance as high as 83.6% have been obtained. These coatings have a figure of merit as good as 0.01 Ω−1 and a remarkably wide spectral transparency region: transmittance higher than 70% down to 1200 nm for 200W-samples. Modelling of the MTC coatings is proposed additionally, based on variable angle spectroscopic ellipsometric measurements, which takes into account the variation of the optical properties of silver when deposited in various conditions and embedded in a semiconductor stack.

In situ study of electrochemical processes of metal nano-nuclei formation, growth, and stability on single carbon microfiber for surface multifunctionalization

With better understanding and control of metal layer formation on carbon surface, the electrical, magnetic, thermal, interfacial, and catalytic characteristics of carbon-based micro- and nanomaterials can be further improved for large-scale engineering applications. Experiments demonstrated that controlled metal electrodeposition on micro- and nanocarbon fibers can be realized in a cost-effective and reproducible fashion. Microbeam synchrotron X-ray diffraction and fluorescence techniques have been developed to provide in situ characterization capabilities to reveal the nuclei formation and growth processes on individual carbon microfibers with size, distribution, and microstructural information. The nuclei stability of the metal deposit is found to have strong dependence on its size as well as the deposition condition.

Effects of Sputter Order and Oxide Layer on Amorphous Formation of Zr-Ni Thin Film System

Effects of the sputtering order and the presence of an oxide layer on an amorphous metal layer formation of zirconium-nickel bilayer thin films annealed at 623 K (350°C) have been investigated. Nickel species are found to diffuse preferentially from the nickel layer into the zirconium layer in Zr/Ni bilayer thin film. From this diffusion, the amorphous phase and voids are formed. However, by the change of the sputtering order and with the formation of a Zr oxide layer, the amorphous and voids are not formed. This indicates that nickel species migrate into the amorphous layer by means of vacancies. Vacancies are supplied from the zirconium-free surface.

Electroluminescence of poly(hydroxyamino esters)-aluminum complexes

We demonstrate that the synthesis of polymer complexes (PHAE-A1) occurs between poly(hydroxyamino esters) (PHAEs) and aluminum by using the conventional vacuum deposition method in the process of thin metal layer formation on the surface of the polymer. These complexes exhibit electroluminescence similar in spectral characteristics to the well-known low-molecular tris(8-quinolinolato) aluminum complex (Alq 3). Spectral and electrical data for the polymer light-emitting diodes A1/PHAE-A1/PHAE/PANI with PHAEs of various chemical structure are reported.

Video tape manufacture by high vacuum evaporation—aspects of machine technology

Abstract The next generation of video tapes will use evaporated thin films with their superior properties such as recording density, output level, frequency characteristics and signal-to-noise ratio. This paper describes the metal layer formation by a simple model for the growth of microcolumns at oblique incidence deposition. The most relevant process parameters are discussed. The layout of a production coater is described.

The formation of metal layers

The deposition phenomena observed in the electrodeposition of deposits of Pb, Tl and Cd on to inert substrates of silver and lead are described for potentiostatic conditions. Under sweep conditions, Pb/Ag and Tl/Ag give rise to two peaks, whereas Cd/Pb gives only one. The first peaks are ascribed to the formation of monolayers of metal following the substrate profile; the second peak to multilayer formation with the deposit profile. Systems with large crystallographic dimensional differences are predicted to have only one peak. Phenomena observed in the first peak region are explained in terms of the growth of partial monolayers. Crystal growth processes are observed in the second peak-region, and the peak region for Cd/Pb, with extreme potential-dependence. This dependence is interpreted in terms of a fixed diffusion layer effect with the Nernst equation controlling the concentration at the interface. A model of defect generation explains the time-dependence of the transients.

The formation of metal layers

The deposition phenomena observed in the electrodeposition of deposits of Pb, Tl and Cd on to inert substrates of silver and lead are described for potentiostatic conditions. Under sweep conditions, Pb/Ag and Tl/Ag give rise to two peaks, whereas Cd/Pb gives only one. The first peaks are ascribed to the formation of monolayers of metal following the substrate profile; the second peak to multilayer formation with the deposit profile. Systems with large crystallographic dimensional differences are predicted to have only one peak. Phenomena observed in the first peak region are explained in terms of the growth of partial monolayers. Crystal growth processes are observed in the second peak-region, and the peak region for Cd/Pb, with extreme potential-dependence. This dependence is interpreted in terms of a fixed diffusion layer effect with the Nernst equation controlling the concentration at the interface. A model of defect generation explains the time-dependence of the transients.