scholarly journals Obtaining multilayer coatings by the detonation spraying method

2021 ◽  
Vol 5 (2) ◽  
pp. 148-154
Author(s):  
D.N. Kakimzhanov ◽  
B.K. Rakhadilov ◽  
D.B. Buitkenov ◽  
L.G. Zhurerova ◽  
M.K. Rakhadilov ◽  
...  
Keyword(s):  
Phase Composition ◽  
Multilayer Coating ◽  
Gas Mixture ◽  
Multilayer Coatings ◽  
Al2o3 Coating ◽  
Technological Parameters ◽  
Detonation Spraying ◽  
Al2o3 Phase ◽  
Degree Of Filling ◽  
Spraying Method

This work were studied the effect of technological parameters of detonation spraying on the phase composition and tribological characteristics on the bases of NiCr and Al2O3 coatings. As well as there was obtained and investigated multilayer coating on the bases of NiCr/NiCr- Al2O3/Al2O3 . It was determined that during detonation spraying the phase composition of Al2O3 coatings strongly depends on the degree of filling the borehole with a gas mixture. The a - Al2O3 -phase content in the coatings increases when the degree of filling is 63% and 54%. Only one CrNi3 phase is observed on the diffractograms and only increase of reflex intensity (020) at barrel filling by 58% is observed by sputtering on the bases of NiCr coatings in different degrees of barrel filling. The results of the coating nanohardness study showed that the hardness of the Al2O3 coating increases depending on the content of a- Al2O3 in it. Al2O3 coating has the maximum nanohardness values and is 16.42 GPa at the borehole is filled to 63%. The nanohardness of NiCr coating has the maximum values at barrel filling by 58% and consisting of 8.02 GPa.

scholarly journals Influence of Detonation-Spraying Parameters on the Phase Composition and Tribological Properties of Al2O3 Coatings

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 793
Author(s):  
Nurgamit Kantay ◽  
Bauyrzhan Rakhadilov ◽  
Sherzod Kurbanbekov ◽  
Didar Yeskermessov ◽  
Gulnara Yerbolatova ◽  
...  
Keyword(s):  
Phase Composition ◽  
X Ray Diffraction ◽  
Technological Parameters ◽  
Detonation Spraying ◽  
Spraying Parameters ◽  
Detonation Method ◽  
Al2o3 Phase ◽  
Detonation Gun ◽  
Α Al2o3 ◽  
Degree Of Filling

Al2O3 coatings were applied on the surface of 12Ch18N10T steel by the detonation method at different degrees of filling of the detonation gun. The aim was to study the influence of technological parameters on the formation of the coating’s structure, phase composition and tribological characteristics. The degree of filling the gun with a gas mixture (C2H2/O2) varied from 53% to 68%. X-ray diffraction study showed that the content of α-Al2O3 increases depending on the degree of filling. The results showed that the hardness increases with an increase in the α-Al2O3 phase. When the gun is 53% filled with gas, the Al2O3-based coating has the hardness of 20.56 GPa compared to 58%, 63% and 68% fillings. Tribology tests have shown that the wear rate and friction coefficient of the coating is highly dependent on the degree of filling of the gun.

scholarly journals Preparation and Characterization of NiCr/NiCr-Al2O3/Al2O3 Multilayer Gradient Coatings by Gas Detonation Spraying

Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1524
Author(s):  
Bauyrzhan Rakhadilov ◽  
Dastan Buitkenov ◽  
Zhuldyz Sagdoldina ◽  
Zhanat Idrisheva ◽  
Manira Zhamanbayeva ◽  
...  
Keyword(s):  
Phase Composition ◽  
Ceramic Layer ◽  
Oxygen Mixture ◽  
Gas Mixture ◽  
Powder Materials ◽  
Detonation Spraying ◽  
Mixture Ratio ◽  
Gun Barrel ◽  
Detonation Gun ◽  
Gradient Coatings

This paper investigates the influence of the technological parameters of detonation spraying on the phase composition of NiCr- and Al2O3-based coatings. It was determined that the phase composition of Al2O3 coatings during detonation spraying strongly depends on the barrel filling volume with the gas mixture. The acetylene–oxygen mixture, which is the most frequently used fuel in the detonation spraying of powder materials, was used as a fuel gas. To obtain a ceramic layer based on Al2O3, spraying was performed at an acetylene–oxygen O2/C2H2 mixture ratio of 1.856; the volume of filling of the detonation gun barrel with an explosive gas mixture was 63%. To obtain a NiCr-based metallic layer, spraying was performed at the O2/C2H2 ratio of 1.063; the volume of filling of the detonation gun barrel with an explosive gas mixture was 54%. Based on a study of the effect of the detonation spraying mode on the phase composition of NiCr and Al2O3 coatings, NiCr/NiCr-Al2O3/Al2O3-based multilayer coatings were obtained. Mixtures of NiCr/Al2O3 powders with different component ratios were used to obtain multilayer gradient coatings. The structural-phase composition, mechanical and tribological properties of multilayer gradient metal–ceramic coatings in which the content of the ceramic phase changes smoothly along the depth were experimentally investigated. Three-, five- and six-layer gradient coatings were obtained by alternating metallic (NiCr) and ceramic (Al2O3) layers. The phase composition of all coatings was found to correspond to the removal of information from a depth of 20–30 μm. It was determined that the five-layer gradient coating, consisting of the lower metal layer (NiCr), the upper ceramic layer (Al2O3) and the transition layer of the mechanical mixture of metal and ceramics, is characterized by significantly higher hardness (15.9 GPa), wear resistance and adhesion strength.

scholarly journals Structure and Tribological Properties of Ni–Cr–Al-Based Gradient Coating Prepared by Detonation Spraying

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 218
Author(s):  
Bauyrzhan Rakhadilov ◽  
Meruyert Maulet ◽  
Madi Abilev ◽  
Zhuldyz Sagdoldina ◽  
Rauan Kozhanova
Keyword(s):  
Aluminum Content ◽  
High Hardness ◽  
Technological Parameters ◽  
Coating Structure ◽  
Detonation Spraying ◽  
Filling Degree ◽  
Substrate Level ◽  
Sprayed Coatings ◽  
Spraying Method ◽  
Formation Phase

In this paper, Ni–Cr–Al coatings were deposited using the detonation spraying method. The aim was to investigate how technological parameters influence coating structure formation, phase composition and tribological performances. We observed that the degree to which the barrel is filled with an O2/C2H2 gas mixture strongly influences the chemical composition of manufactured coatings. High degrees of barrel filling led to a decrease in aluminum content in the coating. Filling degrees of 40% and 50% produced sprayed coatings in which only Ni–Cr phases could be found. When the filling degree was reduced up to 25%, Ni–Al phases began to form in the sprayed coatings. Gradient Ni–Cr–Al coatings were produced by gradually reducing the filling degree from 50% to 25%. These coatings are characterized by Ni–Cr near the substrate level with Ni–Cr and Ni–Al phases at higher levels. The results obtained confirm that gradient Ni–Cr–Al coatings exhibit high hardness as well as good wear resistance.

Phase composition and thin structure of the Zr-Y-O layer in Zr-Y-O/Si-Al-N multilayer coatings

2020 ◽  
Author(s):  
M. V. Fedorischeva ◽  
M. P. Kalashnikov ◽  
I. A. Bozhko ◽  
V. P. Sergeev
Keyword(s):  
Phase Composition ◽  
Multilayer Coatings ◽  
Thin Structure

Investigation of Microstructure and Property of Fe3Al/Al2O3 Composites

2010 ◽  
Vol 150-151 ◽  
pp. 1409-1412 ◽  
Author(s):  
Tao Jiang
Keyword(s):  
Heat Treatment ◽  
Phase Composition ◽  
Mechanical Alloying ◽  
Sintering Process ◽  
Composite Powders ◽  
Al2o3 Composite ◽  
Al2o3 Phase ◽  
The Mean ◽  
Xrd Patterns ◽  
Al2o3 Matrix

The Fe3Al/Al2O3 composites were fabricated by pressureless sintering process. The Fe3Al intermetallics compounds powders were fabricated by mechanical alloying and heat treatment, then the Fe3Al powders and Al2O3 powders were mixed and the Fe3Al/Al2O3 composite powders were prepared, so the Fe3Al/Al2O3 composites were fabricated by sintering process at 1700oC for 2h. The phase composition and microstructure of Fe3Al intermetallics compounds powders produced by mechanical alloying and heat treatment were investigated. The phase composition, microstructure and mechanical properties of the Fe3Al/Al2O3 composites sintered bulks were investigated. The XRD patterns results showed that there existed Fe3Al phase and Al2O3 phase in the sintered composites. The Fe3Al/Al2O3 composites sintered bulks exhibited the homogenous and compact microstructure, the Fe3Al particles were homogenously distributed in the Al2O3 matrix, the mean particles size of Fe3Al intermetallics was about 3-5μm. The Fe3Al/Al2O3 composites exhibited more homogenous and compact microstructure with the increase of Fe3Al content in the Al2O3 matrix. The density and relative density of the Fe3Al/Al2O3 composites increased gradually with the increase of Fe3Al content. The fracture strength and fracture toughness of the Fe3Al/Al2O3 composites increased gradually with the increase of Fe3Al content. The elastic modulus and hardness (HRA) of the Fe3Al/Al2O3 composites decreased gradually with the increase of Fe3Al content.

scholarly journals Effect of structure on properties of Al2O3 and Al (or Ti) mechanical mixture coatings produced by multichamber detonation spraying method

2017 ◽  
Vol 2017 (9) ◽  
pp. 33-39
Author(s):  
L.I. Markashova ◽  
◽  
Yu.N. Tyurin ◽  
O.V. Kolisnichenko ◽  
E.N. Berdnikova ◽  
...  
Keyword(s):  
Mechanical Mixture ◽  
Detonation Spraying ◽  
Spraying Method ◽  
Effect Of Structure

scholarly journals Optical fluxes propagation in the planar transport layer of multilayer coatings

2021 ◽  
Vol 2144 (1) ◽  
pp. 012013
Author(s):  
E V Egorov ◽  
V K Egorov
Keyword(s):  
Optical Waveguides ◽  
Total Internal Reflection ◽  
Multilayer Coating ◽  
Transport Layer ◽  
Multilayer Coatings ◽  
Resonance Mechanism ◽  
Layer Width ◽  
Efficiency Comparison ◽  
Resonance Propagation ◽  
Waveguide Resonance

Abstract The article is concerned with peculiarities study of the quasimonochromatic optical fluxes propagation through thin planar transparent layer of multilayer coating. There is shown that these fluxes can be transported by the layer in process of its multiple consequtive total internal reflection or by the waveguide-resonance propagation manner depending on correlation between the layer width and the radiation coherence length half of transported fluxes. Efficiency comparison of these radiation transportation mechanisms showed that the waveguide-resonance propagation approach is more adequate for results description of the optical waveguides functioning. It allowed to conclude that optical waveguides (fibers) function in frame of the waveguide-resonance paradigm and the waveguide-resonance mechanism is responsible for the light fluxes transportation on great distances.

scholarly journals Phase composition of coatings on the D16 alloy during micro-arc oxdation in alkaline and silicate electrolytes

2020 ◽  
Vol 1,2020 (1,2020 (124)) ◽  
pp. 51-55
Author(s):  
Subbotina V ◽  
Belozerov V ◽  
Sobol’ O
Keyword(s):  
Phase Composition ◽  
Liquid Glass ◽  
Amorphous State ◽  
Practical Significance ◽  
Alkaline Electrolyte ◽  
X Ray ◽  
Micro Arc Oxidation ◽  
Coating Formation ◽  
Al2o3 Phase ◽  
Α Al2o3

Goal. The influence of electrolysis conditions at different electrolyte compositions on the phase formation of coatings obtained by micro-arc oxidation (MDO) on an aluminum alloy D16 was studied. Method. For electrolysis, two types of electrolytes were used: alkaline electrolyte (solution (KOH) in distilled water), silicate electrolyte (with different percentages of Na2SiO3 component). Research results. It was found that the phase composition of the MAO coatings obtained in an alkaline (KOH) electrolyte mainly consists of γ - Al2O3 phases and, to a much lesser extent, the α-Al2O3 phases. An increase in the KOH concentration leads to a shift in the γ – Al2O3 → α – Al2O3 polymorphic reaction toward the formation of the hardest α-Al2O3 phase (corundum). The formation of the preferred orientation of the growth of crystallites of γ – Al2O3 and α – Al2O3 phases during their formation in an alkaline electrolyte was not detected. Scientific novelty. A significant influence on the mechanism and processes of coating formation is made by the addition of liquid glass (Na2SiO3) in the electrolyte. In this case, the growth rate of the coating increases significantly, but the size of the ordering regions decreases from crystalline to X-ray amorphous. The phase composition of the MAO coatings, when they are formed in a silicate electrolyte, varies from a mixture of the γ - Al2O3 phase and mullite (3Al2O3 • 2SiO2) with a low content of liquid glass (10 g/l Na2SiO3) to the formation of only the X-ray amorphous phase with a high content of liquid glass in the electrolyte (50 g/l Na2SiO3). Practical significance. It was concluded that the use of an alkaline or silicate electrolyte with different percentages allows a wide variation of both the phase composition and structural state (α- Al2O3 and γ- Al2O3 phases, mullite (3Al2O3 • 2SiO2) or X-ray amorphous state) and the kinetics of growth the coating itself.

Nanowear of Multilayer [(TiCx/Ti/C)÷a-C]n Coatings

2018 ◽  
Vol 279 ◽  
pp. 153-159 ◽  
Author(s):  
Anna P. Rubshtein ◽  
Alexander B. Vladimirov ◽  
Sergey A. Plotnikov
Keyword(s):  
Wear Rate ◽  
Tool Steel ◽  
Elasticity Modulus ◽  
Multilayer Coating ◽  
Wear Test ◽  
Constant Load ◽  
Multilayer Coatings ◽  
Diamond Indenter ◽  
Low Wear

Hard multilayer coatings are technologically promising materials for reducing wear of tribological parts. Multilayer coatings with a systematic alternation of the pair [(TiCx/Ti/C)÷(a-C)] were deposited on stainless and tool steel by the PVD technique. Hardness (H), elasticity modulus (E) and critical cracking load (Pcr) were determined by the nanoindentation method. Nanofrictional wear test was conducted under multipass sliding of a diamond indenter (Ø 50 nm) under constant load. The specific coefficient of nanofrictional wear of [(TiCx/Ti/C)÷(a-C)]nwith different composition of titanium-containing layers was determined. The nanofrictional wear rate of [(TiCx/Ti/C)÷a-C]ndepends on the elastic and plastic characteristics of multilayer coating as a whole. Coatings having H3/E2> 0.12 and Pcr> 58 mN demonstrate low wear rate.

Influence of the nanostructure of the functional layers of a multilayer coating on the wear of a carbide tool

2021 ◽  
pp. 332-336
Author(s):  
A.A. Vereshchaka ◽  
V.P. Tabakov
Keyword(s):  
Fracture Resistance ◽  
Crack Formation ◽  
Multilayer Coating ◽  
Multilayer Coatings ◽  
Carbide Tool ◽  
Scratch Testing ◽  
Nanolayer Thickness

The results of studies of the effect of nanolayer thickness on the wear of carbide tools are presented. The effect of nanolayer thicknesses on microhardness and fracture resistance of a multilayer coating during scratch testing is shown. The role of nanostructure in the processes of crack formation in multilayer coatings during cutting is revealed.

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