Physical and Mathematical Modeling of a Surface for Plasma Spraying of Wear-Resistant Coatings

2021 ◽  
Vol 50 (3) ◽  
pp. 222-228
Author(s):  
S. V. Kartsev
Author(s):  
E. Lugscheider ◽  
P. Remer ◽  
L. Zhao

Abstract In this investigation reactive plasma spraying was used to produce wear resistant coatings of Ti-carbides/titanium or Ti-nitrides/titanium composites. Ti-powders with different powder size distributions were used as raw materials. Methane and nitrogen were used as reactive gases to form carbides and nitrides. A reactor was adapted to the plasma gun F4 of a Sulzer Metco vacuum plasma spraying equipment to increase the degree of the expected reactions. Phase analysis and micrography of the coatings reveal that the Ti-hardphases were synthesized during spraying and embedded in the titanium matrix. The in situ synthesized hardphases show different forms and sizes. Most of them are non-stoichiometry. Compared to the titanium coating the coatings produced by reactive plasma spraying are much harder and more resistant against both sliding and abrasive wear.


2021 ◽  
Vol 20 (5) ◽  
pp. 369-374
Author(s):  
V. A. Okovity ◽  
F. I. Panteleenko ◽  
V. V. Okovity ◽  
V. M. Astashinsky

The paper presents studies on the optimization of the process of applying coatings from cermet powders with different solid phase contents by plasma spraying in air to restore and harden parts of machines and mechanisms operating under adverse conditions. Such conditions are usually created in heavily loaded tribojoints when the mechanisms operate at a low speed of relative movement of surfaces during friction. At the same time, the destruction of the working surfaces is mainly due to the process of microcontact setting and subsequent detachment of the formed particles at their contact points. The application of special protective coatings with the required properties is possible with the manufacture of high-quality starting powder materials and optimization of the technology for their application. Such powders and powder compositions can be obtained by the method of agglomeration of a fine powder mixture with its subsequent high-temperature sintering. To identify the hardening mechanism of composite coatings made of cermet by gas-thermal spraying, important stages are the optimization of the deposition process parameters and the study of the properties of plasma coatings obtained in this case. When optimizing the technological parameters of plasma spraying of coatings, the utilization rate of the sprayed powder material has been taken into account as the main indicator of the process efficiency, the structure of the obtained layers, and the morphology of individual particles deposited on the polished surface. The paper provides data on the structural elements of sprayed materials for wear-resistant coatings obtained by plasma spraying at optimal conditions. Taking into account the processes that occur during the wear of tribological conjugations, the data indicate the existing prerequisites for the wear resistance of the studied composite coatings made of metal ceramics. Special wear-resistant coatings made of materials with a soft matrix hardened by solid inclusions Al2O3–TiO2–Ni–Cr–Al–Y are widely used in various industries. Based on the detailed analysis of the features of cermet plasma coatings, it can be stated that such powder compositions (complex oxides-metal component) are often used as wear-resistant plasma coatings. The research results can be taken into account in cases of application of wear-resistant plasma coatings made of metal-ceramics and compositions based on them, containing solid phases in the form of oxides, as well as the manufacture of a whole range of parts operating under conditions of intense wear.


2017 ◽  
Vol 270 ◽  
pp. 230-235 ◽  
Author(s):  
Pavel Komarov ◽  
Ladislav Čelko ◽  
David Jech ◽  
Martin Papula ◽  
Karel Slámečka ◽  
...  

Changes in fluids contact angle in the interaction with materials surface can play a critical role in enhancement of hydro-machine components and pipelines efficiency and/or service lifetime. However most nowadays used materials and/or coatings are made from polymers or ceramic polymer composites produced by highly sophisticated and/or very expensive techniques. Unfortunately there are a lack of mechanical properties. With the aim to study the role of the surface topography on the water contact angle changes, the representatives of wear resistant coatings (WC10Co4Cr, Cr2O3+5SiO2+3TiO2and Al2O3) were produced by means of atmospheric plasma spraying. Wettability of the coatings surface was studied by adding the liquid droplet on as sprayed, grinded and polished coating's surface by measuring the changes of its contact angle. To estimate the coatings phase composition and topography XRD technique and optical profilometer were used. The contact angle of water was measured by sessile droplet method. To obtain the complex information of the cross-sectional coatings microstructure the conventional metallographic analysis approaches and optical microscopy were also used.


2020 ◽  
Vol 854 ◽  
pp. 133-139
Author(s):  
V.A. Krasnyy ◽  
Vyacheslav V. Maksarov ◽  
D.D. Maksimov

Modern designs of piston rings of internal combustion engines and wear-resistant coatings used for them are considered. It is noted that the upper (compression) ring undergoes the most intense wear. Among the traditionally used wear-resistant coatings of compression rings, galvanic chrome plating and thermal spraying with molybdenum are most often used. The paper proposes the use of the ion-plasma spraying method for applying hard wear-resistant coatings to the working surface of piston rings based on titanium and molybdenum nitrides. The specified method relates to vacuum coating technologies (PVD methods), in which layers of high-strength materials are sprayed directly onto the surface of the product. The present work aimed to carry out comparative tribotechnical tests of piston ring samples having hard coatings obtained by ion-plasma spraying and to compare them with traditional galvanic chromium plating. A technique has been developed for a comprehensive assessment of comparative tribological characteristics, including the critical load during testing, the specific load of seizing, the coefficients of friction, scoring resistance, and wear resistance. The test results of samples with the galvanic coating with chromium, ion-plasma spraying with titanium nitride, and molybdenum nitride are shown. In contrast, it is shown that samples with an applied ion-plasma coating surpass samples that are electrolytically chrome plated by all tribological parameters. The results obtained allow concluding that the ion-plasma coating of molybdenum nitride is promising for piston rings, as well as other critical parts of internal combustion engines.


2013 ◽  
Vol 34 (3) ◽  
pp. 161-165 ◽  
Author(s):  
S. N. Grigor’ev ◽  
O. B. Kovalev ◽  
V. I. Kuzmin ◽  
A. A. Mikhal’chenko ◽  
N. A. Rudenskaya ◽  
...  

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2344 ◽  
Author(s):  
Satyapal Mahade ◽  
Karthik Narayan ◽  
Sivakumar Govindarajan ◽  
Stefan Björklund ◽  
Nicholas Curry ◽  
...  

Titanium- and chromium-based carbides are attractive coating materials to impart wear resistance. Suspension plasma spraying (SPS) is a relatively new thermal spray process which has shown a facile ability to use sub-micron and nano-sized feedstock to deposit high-performance coatings. The specific novelty of this work lies in the processing of fine-sized titanium and chromium carbides (TiC and Cr3C2) in the form of aqueous suspensions to fabricate wear-resistant coatings by SPS. The resulting coatings were characterized by surface morphology, microstructure, phase constitution, and micro-hardness. The abrasive, erosive, and sliding wear performance of the SPS-processed TiC and Cr3C2 coatings was also evaluated. The results amply demonstrate that SPS is a promising route to manufacture superior wear-resistant carbide-based coatings with minimal in situ oxidation during their processing.


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