scholarly journals Complex restoration of operation surfaces in large-sized products operated under conditions of chemical-biological and abrasive environment

2020 ◽  
Vol 2020 (8) ◽  
pp. 36-41
Author(s):  
Petr Vityaz ◽  
Mikhail Kheyfets ◽  
Nikolai Gretsky ◽  
Dmitriy Hil'ko
Keyword(s):  
Layer By Layer ◽  
Surface Strengthening ◽  
Major Repair ◽  
Complex Approach ◽  
Surface Diagnostics ◽  
Modern Technologies

A complex approach to large-sized parts restoration is shown. There are shown methods developed for parts operation surface restoration depending on a wear degree. There are presented modern technologies and equipment for worn-out surface diagnostics. A method for layer-by-layer restoration and large-sized parts worn-out surface strengthening during product major repair is described. Basic recommendations on operation to increase auger shaft life are given.

Layer-by-Layer Laser Sintering of Powders Irradiated by Gamma Quanta Co60

2014 ◽  
Vol 1040 ◽  
pp. 768-771 ◽  
Author(s):  
A.V. Gradoboev ◽  
E.V. Babakova ◽  
A.A. Saprykin ◽  
Egor A. Ibragimov
Keyword(s):  
Gamma Radiation ◽  
Copper Powder ◽  
Radioactive Isotope ◽  
Laser Sintering ◽  
Layer By Layer ◽  
Metal Powders ◽  
Metallic Powders ◽  
The Matrix ◽  
Preliminary Activation ◽  
Modern Technologies

Metal powders are widely used in many modern technologies, as well as they have been applied in the form of various fillers composites. Recently, in some cases, the preliminary activation of metallic powders is made to improve the compatibility of the filler and the matrix. Undertook a study describe the influence of gamma radiation radioactive isotope Co60 on copper powder. Gamma radiation also affects the character of laser sintering by layer-by-layer synthesis. Through this change was obtained in structure and the properties of the powder. On the whole it affects the process of layering laser sintering products.

scholarly journals FUNCTIONAL COATINGS APPLICATION FOR STRENGTHENING AND RESTORATION OF AVIATION PRODUCTS

Aviation ◽  
2005 ◽  
Vol 9 (4) ◽  
pp. 39-45 ◽  
Author(s):  
Sergey Dmitriyev ◽  
Anatoly Koudrin ◽  
Vasily Labunets ◽  
Miroslav Kindrachuk
Keyword(s):  
Mechanical Properties ◽  
Surface Hardening ◽  
Composite Coatings ◽  
Erosive Wear ◽  
Physical And Mechanical Properties ◽  
Functional Coatings ◽  
Surface Strengthening ◽  
Restoration Techniques ◽  
Modern Technologies ◽  
Practical Recommendations

The article deals with the analysis of modern technologies of surface hardening and restoration of the working parts of aviation products. The technologically sophisticated methods of obtaining multifunctional composite coatings with an application of effective sources of energy are described. These methods permit structures with predetermined physical and mechanical properties to be formed on working surfaces. The results of testing alloys and coatings under conditions of abrasive and erosive wear are tested. Practical recommendations on application of the aircraft parts surface strengthening and restoration techniques, taking into account conditions of operation, are brought forward.

Assessment of the Structural State of the Amorphous Alloys Thin Surface Layers

2019 ◽  
Vol 946 ◽  
pp. 174-180
Author(s):  
Olga M. Kanunnikova ◽  
O.Yu. Goncharov ◽  
V.I. Ladyanov
Keyword(s):  
Electron Spectroscopy ◽  
Amorphous Alloys ◽  
Layer By Layer ◽  
Surface Layers ◽  
Equilibrium Thermodynamics ◽  
X Ray ◽  
Cu Alloy ◽  
Complex Approach ◽  
Layer Analysis ◽  
Combination Of Methods

The complex approach based on the combination of methods of equilibrium thermodynamics and x-ray electron spectroscopy for layer-by-layer analysis of the composition of surface layers of amorphous alloys is described on the example of Fe-Si-B-Nb-Cu alloy.

Microstructural characterization of CoPtCr/Cr thin film disks by cross-section TEM and elongated probe micro-diffraction

1991 ◽  
Vol 49 ◽  
pp. 762-763
Author(s):  
M.A. Parker ◽  
K.E. Johnson ◽  
C. Hwang ◽  
A. Bermea
Keyword(s):  
Magnetic Recording ◽  
Electron Probe ◽  
Microstructural Characterization ◽  
Crystallographic Structure ◽  
Recording Media ◽  
Layer By Layer ◽  
Cross Sectional ◽  
New Techniques ◽  
Polished Side

We have reported the dependence of the magnetic and recording properties of CoPtCr recording media on the thickness of the Cr underlayer. It was inferred from XRD data that grain-to-grain epitaxy of the Cr with the CoPtCr was responsible for the interaction observed between these layers. However, no cross-sectional TEM (XTEM) work was performed to confirm this inference. In this paper, we report the application of new techniques for preparing XTEM specimens from actual magnetic recording disks, and for layer-by-layer micro-diffraction with an electron probe elongated parallel to the surface of the deposited structure which elucidate the effect of the crystallographic structure of the Cr on that of the CoPtCr.XTEM specimens were prepared from magnetic recording disks by modifying a technique used to prepare semiconductor specimens. After 3mm disks were prepared per the standard XTEM procedure, these disks were then lapped using a tripod polishing device. A grid with a single 1mmx2mm hole was then glued with M-bond 610 to the polished side of the disk.

Epitaxial growth manner and structure of superconducting oxide films

1990 ◽  
Vol 48 (4) ◽  
pp. 2-3
Author(s):  
Yoshichika Bando ◽  
Takahito Terashima ◽  
Kenji Iijima ◽  
Kazunuki Yamamoto ◽  
Kazuto Hirata ◽  
...  
Keyword(s):  
Ultrathin Films ◽  
Film Surface ◽  
High Energy ◽  
Epitaxial Films ◽  
Layer By Layer ◽  
Initial Growth ◽  
In Situ Growth ◽  
High Quality ◽  
Activated Reactive Evaporation

The high quality thin films of high-Tc superconducting oxide are necessary for elucidating the superconducting mechanism and for device application. The recent trend in the preparation of high-Tc films has been toward “in-situ” growth of the superconducting phase at relatively low temperatures. The purpose of “in-situ” growth is to attain surface smoothness suitable for fabricating film devices but also to obtain high quality film. We present the investigation on the initial growth manner of YBCO by in-situ reflective high energy electron diffraction (RHEED) technique and on the structural and superconducting properties of the resulting ultrathin films below 100Å. The epitaxial films have been grown on (100) plane of MgO and SrTiO, heated below 650°C by activated reactive evaporation. The in-situ RHEED observation and the intensity measurement was carried out during deposition of YBCO on the substrate at 650°C. The deposition rate was 0.8Å/s. Fig. 1 shows the RHEED patterns at every stage of deposition of YBCO on MgO(100). All the patterns exhibit the sharp streaks, indicating that the film surface is atomically smooth and the growth manner is layer-by-layer.

Compact back-scattered electrons' energy analyzer for standard SEM

1994 ◽  
Vol 52 ◽  
pp. 488-489
Author(s):  
S. Likharev ◽  
A. Kramarenko ◽  
V. Vybornov
Keyword(s):  
Depth Resolution ◽  
High Energy ◽  
Primary Beam ◽  
Layer By Layer ◽  
Energy Analyzer ◽  
High Energy Part ◽  
Small Window ◽  
Energy Part ◽  
Wide Range ◽  
High Voltage Supply

At present time the interest is growing considerably for theoretical and experimental analysis of back-scattered electrons (BSE) energy spectra. It was discovered that a special angle and energy nitration of BSE flow could be used for increasing a spatial resolution of BSE mode, sample topography investigations and for layer-by layer visualizing of a depth structure. In the last case it was shown theoretically that in order to obtain suitable depth resolution it is necessary to select a part of BSE flow with the directions of velocities close to inverse to the primary beam and energies within a small window in the high-energy part of the whole spectrum.A wide range of such devices has been developed earlier, but all of them have considerable demerit: they can hardly be used with a standard SEM due to the necessity of sufficient SEM modifications like installation of large accessories in or out SEM chamber, mounting of specialized detector systems, input wires for high voltage supply, screening a primary beam from additional electromagnetic field, etc. In this report we present a new scheme of a compact BSE energy analyzer that is free of imperfections mentioned above.

Transmission Electron Microscopy characterization of epitaxial III-V semiconductor thin films grown on Si(100) by ion-assisted deposition

1990 ◽  
Vol 48 (4) ◽  
pp. 686-687
Author(s):  
L. Hultman ◽  
C.-H. Choi ◽  
R. Kaspi ◽  
R. Ai ◽  
S.A. Barnett
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ion Irradiation ◽  
High Energy ◽  
Nucleation Mechanism ◽  
Layer By Layer ◽  
Extended Defect ◽  
Island Formation ◽  
Si Substrates ◽  
Transmission Electron

III-V semiconductor films nucleate by the Stranski-Krastanov (SK) mechanism on Si substrates. Many of the extended defects present in the films are believed to result from the island formation and coalescence stage of SK growth. We have recently shown that low (-30 eV) energy, high flux (4 ions per deposited atom), Ar ion irradiation during nucleation of III-V semiconductors on Si substrates prolongs the 1ayer-by-layer stage of SK nucleation, leading to a decrease in extended defect densities. Furthermore, the epitaxial temperature was reduced by >100°C due to ion irradiation. The effect of ion bombardment on the nucleation mechanism was explained as being due to ion-induced dissociation of three-dimensional islands and ion-enhanced surface diffusion.For the case of InAs grown at 380°C on Si(100) (11% lattice mismatch), where island formation is expected after ≤ 1 monolayer (ML) during molecular beam epitaxy (MBE), in-situ reflection high-energy electron diffraction (RHEED) showed that 28 eV Ar ion irradiation prolonged the layer-by-layer stage of SK nucleation up to 10 ML. Otherion energies maintained layer-by-layer growth to lesser thicknesses. The ion-induced change in nucleation mechanism resulted in smoother surfaces and improved the crystalline perfection of thicker films as shown by transmission electron microscopy and X-ray rocking curve studies.

Sign in / Sign up

Export Citation Format

Share Document