scholarly journals Metallographic studies results of 20kH13 steel samples with textured relief, modified surface and protective coating

2019 ◽  
Vol 140 ◽  
pp. 02009
Author(s):  
Alexey Mednikov ◽  
Aleksandr Tkhabisimov ◽  
Marat Dasaev ◽  
Andrey Burmistrov ◽  
Olga Zilova
Keyword(s):  
Surface Relief ◽  
Near Surface ◽  
Polyurethane Coatings ◽  
Ion Plasma ◽  
Steam Turbine Blade ◽  
Modified Surface ◽  
Nitrogen Ions ◽  
Proven Method ◽  
Blade Steel ◽  
Smart Surface

One of the possible ways to improve passive methods of the steam turbine blade material protection from water droplet erosion is to create “smart”-surface that combines the properties and characteristics that could not be implemented simultaneously when using one or another proven method of protection. To solve the problem of developing such surface, this article presents the metallographic researches results of the blade steel 20kH13 samples with various already used and promising passive methods of protection, consisting in the use of ion-plasma and polyurethane coatings, surface modification by means of diffusion saturation with nitrogen ions, creation of the structured surface relief by laser ablation. The results of the carried out researches have allowed to reveal both morphology of a possible “smart”-surface, and influence on a microstructure and characteristics of a near-surface layer of samples after treatments considered.

Structural-Mechanical Properties of Polyurethane Surface after Carbon Ion Subplantation

2021 ◽  
Vol 887 ◽  
pp. 370-375
Author(s):  
I.A. Morozov ◽  
A.S. Kamenetskikh
Keyword(s):  
Mechanical Properties ◽  
Surface Relief ◽  
Low Energy ◽  
Plasma Modification ◽  
Carbon Ions ◽  
Uniaxial Deformation ◽  
Treatment Regimes ◽  
Subsequent Investigation ◽  
Ion Plasma ◽  
Potential Applications

Ion-plasma modification of polymers has many potential applications, in particular, in the development of biomedical products. Treatment of soft polymers can easily damage the surface; low-energy plasma and subsequent investigation of the structural and mechanical properties of the surface are required. Polyurethane is a widely used block copolymer. Subplantation of carbon ions heterogeneously changes the structural and mechanical properties of the surface (relief, stiffness, thickness of the modified coating), forming a graphene-like nanolayer. Uniaxial deformation of the treated materials in some cases leads to the damage of the surface (local nanocracks, folds). Materials have increased hydrophobicity, good deformability (valid for certain treatment regimes) and can find application in design of products with improved biomedical properties.

Mechanisms Influencing the Formation of the Carbonized Layer Relief on the Polymer Surface after the Ion-Plasma Treatment Modeling

2018 ◽  
Vol 938 ◽  
pp. 148-155
Author(s):  
A.Yu. Belyaev ◽  
A.L. Svistkov
Keyword(s):  
Plasma Treatment ◽  
Strain State ◽  
Polymer Surface ◽  
Polymer Chains ◽  
Simple Explanation ◽  
Near Surface ◽  
Ion Flow ◽  
Ion Plasma ◽  
Unit Surface ◽  
Material Heating

The work is devoted to the discussion of hypotheses that are put forward to explain the processes occurring during ion-plasma treatment of polyurethane. A carbonized layer forms on the surface of the polymer as a result of ion-plasma treatment. However this layer is not even. Wavy relief, the geometric features of which depend on the fluence (the number of ions entering the unit surface of the sample) and the energy of ions, is formed. It is shown that a simple explanation related to material heating and subsequent shrinkage does not allow explaining the cause of the phenomenon. The second hypothesis can be the pressure of the ion flow on the surface of the sample. It causes deformation and subsequent changes in the stress-strain state after the irradiation is stopped. Calculations show that this mechanism cannot explain the formation of the folded relief of the layer. A hypothesis, based on information about a significant material change, is expressed in the article. Polymer chains under ion-plasma treatment are broken into atoms. After striking ions move deep into the material causing the polymer to swell in the near-surface layer. This swelling can cause material to move close to the sample boundary and leads to the formation of a wavy surface.

Ion Bombardment Effects on GaAs Using 100eV Nitrogen Ions

1988 ◽  
Vol 128 ◽  
Author(s):  
W. M. Lau
Keyword(s):  
Photoelectron Spectroscopy ◽  
Molecular Nitrogen ◽  
Polar Angle ◽  
Ion Bombardment ◽  
Molecular Ions ◽  
Near Surface ◽  
Nitrogen Ions ◽  
Gallium Nitrides ◽  
Nitrogen Ion ◽  
P Type

ABSTRACTThe ion bombardment effects of low energy molecular nitrogen ions (100eV) on GaAs have been investigated using in-situ polar angle dependent X-ray photoelectron spectroscopy. It was found that arsenic and gallium nitrides were formed as a result of the nitrogen ion bombardment. The ion bombardment also caused a depletion of arsenic in the near surface region. For example, with a dose of 6×1015 cm-2 of nitrogen molecular ions at 100eV, the surface structure can be described approximately as 1.5nm of Ga0.67A0.33N on GaAs. The ion bombardment moves the Fermi levels of both n-type and p-type GaAs to mid-gap. Heating the ion bombarded samples in a vacuum chamber to 500°C desorbs all arsenic nitrides but most of the gallium nitrides remain on the surface. The Fermi levels of both n-type and p-type are then stablized at about 0.4eV from the valence band maximum. A surface type-inversion of the n-type substrate is therefore induced by the nitrogen-ionbombardment/annealing treatment.

Fatigue life estimation of pitted 12% Cr steam turbine blade steel in different environments and at different stress ratios

2014 ◽  
Vol 65 ◽  
pp. 33-43 ◽  
Author(s):  
Bernd M. Schönbauer ◽  
Stefanie E. Stanzl-Tschegg ◽  
Andrea Perlega ◽  
Ronald N. Salzman ◽  
Neville F. Rieger ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Steam Turbine ◽  
Turbine Blade ◽  
Life Estimation ◽  
Fatigue Life Estimation ◽  
Steam Turbine Blade ◽  
Stress Ratios ◽  
Blade Steel

Replicated Polymer Light Guide Interconnector with Depth Modified Surface Relief Grating Couplers

2007 ◽  
Vol 14 (5) ◽  
pp. 304-309 ◽  
Author(s):  
Samuli Siitonen ◽  
Juha Pietarinen ◽  
Pasi Laakkonen ◽  
Konstantins Jefimovs ◽  
Markku Kuittinen ◽  
...  
Keyword(s):  
Surface Relief ◽  
Light Guide ◽  
Grating Couplers ◽  
Surface Relief Grating ◽  
Modified Surface

Nanostructure of 45# Carbon Steel by High Current Pulsed Electron Beam

2009 ◽  
Vol 79-82 ◽  
pp. 317-320
Author(s):  
Hui Zou ◽  
H.R. Jing ◽  
Sheng Zhi Hao ◽  
Chuang Dong
Keyword(s):  
Surface Layer ◽  
Electron Beam ◽  
Electron Microscope ◽  
Carbon Steel ◽  
Short Pulse ◽  
White Layer ◽  
High Current ◽  
Near Surface ◽  
Pulsed Electron Beam ◽  
Modified Surface

When high current pulsed electron beam (HCPEB) transferring its energy into a very thin surface layer within a short pulse time, super fast processes such as heating, melting, evaporation and consequent solidification, as well as dynamic stress induced may impart the surface layer with improved properties. In this paper, HCPEB modification of 45# carbon steel with working parameters of electron energy 25 kV, pulse duration 3.5µs, and energy density 4 J/cm2 was investigated. The microstructures of modified surface were analyzed by scanning electron microscope (SEM) of type JSM 5310 and transmission electron microscope (TEM) of type H-800. It is found that the modified surface layer can be divided into three zones: the white layer or melted layer of depth 3 to10µm, the heat and stress effecting zone 10 µm below and about 250 µm, then matrix, where a nanostructure and/or amorphous layer formed in the near-surface region. It is proved that the whole treatment process is not complex and cost-effective, and has a substantial potential to be applied in industries.

Effect of simultaneous B+ and N+2 implantation on microhardness, fatigue life, and microstructure in Fe–13Cr–15Ni base alloys

1989 ◽  
Vol 4 (6) ◽  
pp. 1371-1378 ◽  
Author(s):  
E. H. Lee ◽  
L. K. Mansur
Keyword(s):  
Fatigue Life ◽  
Fatigue Tests ◽  
Dislocation Slip ◽  
Transmission Electron ◽  
Austenitic Alloys ◽  
Life Improvement ◽  
Modified Surface ◽  
Nitrogen Ions ◽  
Alloying Compositions ◽  
Modified Surface Layer

Microhardness and cantilever beam fatigue measurements were conducted on Fe–13Cr–15Ni base austenitic alloys that were implanted with boron and nitrogen ions either singly or simultaneously. The microstructure of the modified surface layer and dislocation slip modes after fatigue tests were investigated by optical and transmission electron microscopy. Both hardness and fatigue life were improved by ion implantation, but the greatest improvement was achieved when boron and nitrogen were implanted simultaneously. The degree of fatigue life improvement also varied with minor changes in the base alloying compositions: nitrogen was detrimental or ineffective in the presence of titanium, and boron was much more effective in the presence of molybdenum. Comparison of slip band morphology between the compression and tension cycles indicated that implantation improved the reversibility of surface slip and delayed crack initiation.

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