scholarly journals The influence of pulse-plasma treatment on the phase composition and hardness of Fe-TiB2-CrB2 coatings

2021 ◽  
Vol 5 (2) ◽  
pp. 155-162
Author(s):  
A.B. Kengesbekov ◽  
B.K. Rakhadilov ◽  
Yu.N. Tyurin ◽  
N.M. Magazov ◽  
M.K. Kylyshkanov ◽  
...  

This work are presented the research results of pulse plasma treatment influence on the phase composition, hardness, roughness and element composition of coatings on the bases of Fe-TiB2-CrB2. The Fe-TiB2-CrB2 coating was deposited by detonation method. The following pulse-plasma treatment was used to modify the structure and properties of the surface layers of the sprayed coating. The results of mechanical experiments showed that the hardness of Fe-TiB2-CrB2 coating increased after the treatment. On the basis of the X-ray analysis, it has been established that the increase of coating hardness is connected with phase transformations in a surface layer, in particular, with formation of oxide phases and increase of carbide particles quantity.

2021 ◽  
Vol 5 (1) ◽  
pp. 45-51
Author(s):  
D.N. Kakimzhanov ◽  
B.K. Rakhadilov ◽  
Yu.N. Tyurin ◽  
O.V. Kolisnichenko ◽  
L.G. Zhurerova ◽  
...  

In this study, the research results of the influence of pulsed plasma treatment on phase composition, hardness, and roughness of Cr3C2-NiCr coatings are presented. The Cr3C2-NiCr coating was applied to substrate 12Kh18N10T stainless steel by detonation spraying method. To change the physical and mechanical properties of sprayed coating’s surface layers, subsequent pulse-plasma treatment was used. The pulse-plasma treatment leads to changing the roughness of Cr3C2-NiCr coating. The results of mechanical tests showed that after pulsed plasma treatment, the hardness of Cr3C2-NiCr coating is increased. Based on X-ray diffraction analysis, it was found that the hardness increasing of coating is associated with phase transformations on the surface layer, in particular, the formation of the oxide phase and an increase in the number of carbide particles.


Author(s):  
Vladimir A. Terekhov ◽  
Evgeny I. Terukov ◽  
Yury K. Undalov ◽  
Konstantin A. Barkov ◽  
Igor E. Zanin ◽  
...  

Amorphous SiOx films with silicon nanoclusters are a new interesting material from the standpoint of the physics, technology, and possible practical applications, since such films can exhibit photoluminescence due to size quantization. Moreover, the optical properties of these structures can be controlled by varying the size and the content of silicon nanoclusters in the SiOx film, as well as by transforming nanoclusters into nanocrystals by means of high-temperature annealing. However, during the annealing of nonstoichiometric silicon oxide, significant changes can occur in the phase composition and the structure of the films. The results of investigations on the crystallization of silicon nanoclusters in a SiOx matrix have shownthat, even a very fast method of annealing using PPA leads to the formation of large silicon crystallites. This also causes the crystallization of at least a part of the oxide phase in the form of silicon hydroxide H6O7Si2. Moreover, in films with an initial content of pure silicon nanoclusters ≤ 50%, during annealing a part of the silicon is spent on the formation of oxide, and part of it is spent on the formation of silicon crystals. While in a film with an initial concentration of silicon nanoclusters ≥ 53%, on the contrary, upon annealing, there occurs a partial transition of silicon from the oxide phase to the growth ofSi crystals        Reference 1. Undalov Y. K., Terukov E. I., Silicon nanoclustersncl-Si in a hydrogenated amorphous silicon suboxidematrix a-SiOx:H (0 < x < 2). Semiconductors. 2015;49(7):867- 878. DOI: https://doi.org/10.1134/S10637826150702222. Kim K. H., Johnson E. V., Kazanskii A. G.,Khenkin M. V., Roca P. Unravelling a simple methodfor the low temperature synthesis of siliconnanocrystals and monolithic nanocrystalline thinfilms. Scientific Reports. 2017;7(1) DOI: https://doi.org/10.1038/srep405533. Undalov Y. K., Terukov E. I., Trapeznikova I. N.Formation of ncl-Si in the amorphous matrix a-SiOx-:H located near the anode and on the cathode, usinga time-modulated DC plasma with the (SiH4–Ar–O2)gas phase (Co2 = 21.5 mol%). Semiconductors.2019;53(11): 1514–1523. DOI: https://doi.org/10.1134/S10637826191102284. Terekhov V. A., Terukov E. I., Undalov Y. K.,Parinova E. V., Spirin D. E., Seredin P. V., Minakov D. A.,Domashevskaya E. P. Composition and optical propertiesof amorphous a-SiOx:H films with silicon nanoclusters.Semiconductors. 2016;50(2): 212–216. DOI:https://doi.org/10.1134/S10637826160202515. Terekhov V. A., Turishchev S. Y., Kashkarov V. M.,Domashevskaya E. P., Mikhailov A. N., Tetel’baum D. I.Silicon nanocrystals in SiO2 matrix obtained by ionimplantation under cyclic dose accumulation. PhysicaE: Low-dimensional Systems and Nanostructures.2007;38(1-2): 16–20. DOI: https://doi.org/10.1016/j.physe.2006.12.0306. Terekhov V. A., Turishchev S. Y., Pankov K. N.,Zanin I. E., Domashevskaya E. P., Tetelbaum D. I.,Mikhailov A. N., Belov A. I., Nikolichev D. E., Zubkov S. Y.XANES, USXES and XPS investigations of electronenergy and atomic structure peculiarities of the siliconsuboxide thin film surface layers containing Si nanocrystals.Surface and Interface Analysis. 2010;42(6-7):891–896. DOI: https://doi.org/10.1002/sia.33387. Terekhov V. A., Turishchev S. Y., Pankov K. N.,Zanin I. E., Domashevskaya E. P., Tetelbaum, MikhailovA. N., Belov A. I., Nikolichev D. E. Synchrotron investigationsof electronic and atomic-structure peculiaritiesfor silicon-oxide films’ surface layers containingsilicon nanocrystals. Journal of Surface Investigation.X-ray, Synchrotron and Neutron Techniques. 2011;5(5):958–967. DOI: https://doi.org/10.1134/S102745101110020X8. Sato K., Izumi T., Iwase M., Show Y., Morisaki H.,Yaguchi T., Kamino T. Nucleation and growth of nanocrystallinesilicon studied by TEM, XPS and ESR.Applied Surface Science. 2003;216 (1-4): 376–381. DOI:https://doi.org/10.1016/S0169-4332(03)00445-89. Ledoux G., Gong J., Huisken F., Guillois O., ReynaudC. Photoluminescence of size-separated siliconnanocrystals: Confirmation of quantum confinement.Applied Physics Letters. 2002;80(25): 4834–4836. DOI:https://doi.org/10.1063/1.148530210. Patrone L., Nelson D., Safarov V. I., Sentis M.,Marine W., Giorgio S. Photoluminescence of siliconnanoclusters with reduced size dispersion producedby laser ablation. Journal of Applied Physics. 2000;87(8):3829–3837. DOI: https://doi.org/10.1063/1.37242111. Takeoka S., Fujii M., Hayashi S. Size-dependentphotoluminescence from surface-oxidized Si nanocrystalsin a weak confinement regime. Physical ReviewB. 2000;62(24): 16820–16825. DOI: https://doi.org/10.1103/PhysRevB.62.1682012. Ievlev V. M. Activation of solid-phase processesby radiation of gas-discharge lamps, Russian ChemicalReviews. 2013;82(9): 815–834. DOI: https://doi.org/10.1070/rc2013v082n09abeh00435713. Zimkina T. M., Fomichev V. A. Ultrasoft X-Rayspectroscopy. Leningrad: Leningrad State UniversityPubl.; 1971. 132 p.14. Wiech G., Feldhütter H. O., Šimůnek A. Electronicstructure of amorphous SiOx:H alloy filmsstudied by X-ray emission spectroscopy: Si K, Si L, andO K emission bands. Physical Review B. 1993;47(12):6981–6989. DOI: https://doi.org/10.1103/Phys-RevB.47.698115. Domashevskaya E. P., Peshkov Y. A., TerekhovV. A., Yurakov Y. A., Barkov K. A., Phase compositionof the buried silicon interlayers in the amorph o u s m u l t i l a y e r n a n o s t r u c t u r e s[(Co45Fe45Zr10)/a-Si:H]41 and [(Co45Fe45Zr10)35(Al2O3)65/a-Si:H]41. Surface and Interface Analysis.2018;50(12-13): 1265–1270. DOI: https://doi.org/10.1002/sia.651516. Terekhov V. A., Kashkarov V. M., ManukovskiiE. Yu., Schukarev A. V., Domashevskaya E. P.Determination of the phase composition of surfacelayers of porous silicon by ultrasoft X-ray spectroscopyand X-ray photoelectron spectroscopy techniques.Journal of Electron Spectroscopy and Related Phenomena.2001;114–116: 895–900. DOI: https://doi.org/10.1016/S0368-2048(00)00393-517. JCPDS-International Centre for DiffractionData ICDD PDF-2, (n.d.) card No 01-077-2110.18. JCPDS-International Centre for DiffractionData ICDD PDF-2, (n.d.) card No 00-050-0438.


Author(s):  
V. G. Shmorgun ◽  
A. I. Bogdanov ◽  
O. V. Slautin ◽  
V. P. Kulevich

The phase composition of the oxide films on the surface of the Fe-Cr-Al system coatings is studied using glancing angle X-ray diffraction. It is shown that at 900 °С the formed oxide films consist of αAlO and (FeCr)O, to which FeAlO oxide is added during long-term exposure. An increase in temperature to 1100 °C intensifies the growth of oxide films, and an increase in the aluminum content ensures a stable growth of αAlO and FeAlO oxides. When the aluminum content in the coating is more than 10 at. % at large exposure times, metastable alumina δAlO is formed, the formation of which is associated with a decrease in the concentration of chromium in thin surface layers.


2021 ◽  
Vol 102 (2) ◽  
pp. 33-39
Author(s):  
B.K. Rakhadilov ◽  
◽  
D.B. Buitkenov ◽  
M. Adilkhanova ◽  
Zh.B. Sagdoldina ◽  
...  

The paper considers the study results of the phase composition and microhardness of detonation coatings based on Ti-Si-C after exposure to pulsed plasma treatment. The CCDS2000 detonation complex was used to obtain the coatings. Coatings surface modification was carried out using pulsed plasma exposure (PPE). The detonation coatings were treated with varying the distance H (30 mm mode 1, 40 mm mode 2, 50 mm mode 3) from the plasmatron to the hardened surface. It is shown that the treated coatings are generally characterized by high microhardness compared to the original coating. It was determined that after treatment by pulsed plasma effects an increase in the intensity of all reflexes phase Ti3SiC2 was observed, and the appearance of reflexes (101, 102, 112, 204, 0016) phase Ti3SiC2 was found, which indicates the increase of the content of Ti3SiC2 phase. The change in the fraction of phases indicates a solid-phase transformation during pulsed-plasma activation. High hardness is observed on the coating surface treated according to mode 3 (50 mm) and as it approaches the surface of the substrate modes 2 (40 mm) and 1 (30 mm) the hardness decreases. It is established that the increase in the microhardness of detonation coatings after pulse-plasma treatment is associated with an increase in the content of Ti3SiC2 phases in the coatings, as well as an increase in the defects density in the modified layer.


Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 779
Author(s):  
Marina Kovaleva ◽  
Igor Goncharov ◽  
Vseslav Novikov ◽  
Maxim Yapryntsev ◽  
Olga Vagina ◽  
...  

Composite ZrB2–MoSi2 coating modified by Y2O3 and Al was prepared by a new multi-chamber detonation accelerator (MCDS) on carbon/carbon composites. Postdeposition heat treatment of the samples at 1500 °C for 1 and 6 h was carried out in air. The effect of heat treatment on the microstructure and phase composition of the ZrB2–MoSi2 coating was investigated by scanning electron microscopy and X-ray diffraction phase analysis. The as-sprayed coating presented as a dense lamellar structure, composed of m-ZrO2, t-ZrO2, some hexagonal ZrB2, and cubic Al phases. The m-ZrO2, c-ZrO2, and h-(α-Al2O3) formed at 1500 °C. The coatings after heat treatment (1 and 6 h) exhibited a structure without cracks. The porosity (~1%) of the coating did not change after heat treatment. Thin, continuous, silica-rich film covered the surfaces of ZrO2 and Al2O3 particles, and could have played a role during heat treatment by acting as a grain lubricant for particle rearrangement.


2012 ◽  
Vol 601 ◽  
pp. 64-68 ◽  
Author(s):  
Маzhyn Skakov ◽  
Bauyrzhan Rakhadilov ◽  
Michail Scheffler

Mechanical characteristics of nitrated and carbonitriding in electrolyte plasma steel Р6М5 surface layers are investigated in the research. It shows perspectiveness of the cutting tool electrolyte-plasma treatment technology. Comparative research of structure, phase composition of fast-cutting P6M5 steel modified surface layers after electrolyte plasma treatment was carried out by scanning-electron and light microscopy, and X-ray structure analysis methods.


2012 ◽  
Vol 452-453 ◽  
pp. 77-80 ◽  
Author(s):  
Shou Jun Wu ◽  
Gutmanas Elazar

In order to improve oxidation/erosion resistance of the T/P 24 steel components used in advanced power plants, chrome carbide coatings were prepared by PIRAC (Powder Immersion Reaction Assisted Coating) on T/P24 at 700-1000°C. Microstructure and phase composition of the obtained surface layers were characterized employing X-ray diffraction and scanning electron microscopy with chemical analysis (SEM/EDS). Results showed that homogenous smooth chrome carbide coatings can be formed on the substrate. Phase composition of the prepared coatings are differs with PIRAC temperatures. Prepared at lower temperatures or short times treatment, Cr23C6, Cr7C3 and Cr3C2 can be detected in the coatings. While, at higher temperatures or longer treatment times, Cr23C6 is subtotal phase of the produced coating. Moreover, the lower the PIRAC temperature is, the more of Cr7C3 and Cr3C2 are. Thermodynamics calculation based on Gibbs free energy is applied to explain phase composition difference of the coatings.


2012 ◽  
Vol 531-532 ◽  
pp. 627-631 ◽  
Author(s):  
Mazhin Skakov ◽  
Bauyrzhan Rakhadilov ◽  
Michael Sheffler

Microhardness of nitrated and carbonitriding in electrolyte plasma steel Р6М5 surface layers are investigated in the research. It shows perspectiveness of the cutting tool electrolyte-plasma treatment technology. Operating conditions for the technology realization are defined. It was also indicated the desired content of components in saturating mixtures by nitriding and carbonitriding. Comparative research of structure, phase composition of fast-cutting P6M5 steel modified surface layers after electrolyte plasma treatment was carried out by scanning-electron and light microscopy, and X-ray structure analysis methods. The way of electrolytic plasma nitriding in cathodic mode, to provide fast-cutting steels which allows for modification the surface and high kinetic efficiency the process diffusion saturation. It was established that as a result of nitriding and nitrocarburizing in plasma electrolyte has been a significant increase in microhardness in the surface layers of steel Р6M5.


Author(s):  
C. Gaudin ◽  
P. Jacquot ◽  
P. Prince ◽  
D. Rivolet ◽  
J.P. Duhamel

Abstract Duplex processes consist in applying a treatment, like annealing, carburizing, or nitriding for example, to a plasma sprayed coating in order to improve particular physical characteristics of this coating. Trials of vacuum heat treatment or low pressure carburizing have been performed on APS NiCr coatings, previously sprayed on a steel type 16MnCr5. As a result, densification and adherence of the coating on the substrate have been significantly increased. To a lesser extent, the coating hardness has also gone up. The diffusion of chemical elements have been highlighted by X-Ray analysis, showing the creation of a physicochemical bonding at the interface zone.


2018 ◽  
Vol 910 ◽  
pp. 31-34
Author(s):  
Tie Jun Zhao ◽  
Hong Hao Yan ◽  
Xiao Jie Li ◽  
Yang Wang

An easy and fast vacuum detonation method was designed to prepare TiO2/Na2Ti6O13 powders. The mixed explosives, prepared by usage of Ti-Na-contained precursor, ammonium nitrate, hexogen and a certain mass of polystyrene foam ball (EPS) in beaker, were detonated in a vacuum detonation reactor to synthesize powders. The prepared light-grey powders were characterized by powder X-ray diffractometer and transmission electron microscopy to ascertain the phase composition and morphology. It was found that the powders were consisted of TiO2 and Na2Ti6O13, and the TiO2 almost was rutile phase. The intensity of Na2Ti6O13 peak was enlarged with increase of EPS mass. The TiO2/Na2Ti6O13 particles were irregular sphere or long rhombus, and some particles were 10 nm. In general, the dispersity of the powers was decreased with the mass of EPS increasing.


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