scholarly journals Optimization of Coating Process from Cermet Powders by Plasma Spraying in Air

2021 ◽  
Vol 20 (5) ◽  
pp. 369-374
Author(s):  
V. A. Okovity ◽  
F. I. Panteleenko ◽  
V. V. Okovity ◽  
V. M. Astashinsky
Keyword(s):  
Plasma Spraying ◽  
Solid Phase ◽  
Protective Coatings ◽  
Composite Coatings ◽  
Polished Surface ◽  
Powder Materials ◽  
Wear Resistant ◽  
Wear Resistant Coatings ◽  
Contact Points ◽  
Plasma Coatings

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.

Reactive Plasma Spraying of Wear Resistant Coatings of Ti Composites

1996 ◽  
Author(s):  
E. Lugscheider ◽  
P. Remer ◽  
L. Zhao
Keyword(s):  
Plasma Spraying ◽  
Raw Materials ◽  
Powder Size ◽  
Titanium Coating ◽  
Vacuum Plasma Spraying ◽  
Wear Resistant ◽  
Plasma Gun ◽  
Wear Resistant Coatings ◽  
Reactive Plasma Spraying ◽  
Reactive Plasma

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.

Effects of 316SS addition on the properties of the coatings based on Al2O3 applied by plasma spraying

2018 ◽  
Vol 52 (19) ◽  
pp. 2597-2608
Author(s):  
Amal Chebbi ◽  
Vincent Guipont ◽  
Khaled Elleuch ◽  
Michel Jeandin
Keyword(s):  
Plasma Spraying ◽  
Composite Structures ◽  
Steel Substrate ◽  
Composite Coatings ◽  
Lamellar Microstructure ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
Wear Resistant Coatings ◽  
Dense Microstructure ◽  
Carrier Gases

Ceramic plasma-sprayed coatings are successfully used for prolonging the service life of industrial components where high wear and corrosion resistance are required. In this work, various types of coatings based on alumina were deposited by atmospheric plasma spraying on 304 L austenitic stainless steel substrate. These coatings were used in further tribological studies. For the atmospheric plasma spraying applications, spraying parameter choices such as carrier gases, plasma enthalpy, current intensity, spraying distance, and particles granulometry are the key issues. Two kinds of Al2O3 particle sizes 2–12 µm (Amperit) and 15–45 µm (Norton) were used to prepare pure and composite coatings. The spraying distance was varied from 90 mm to 120 mm. Microstructure characterization performed by scanning electron microscopy showed that the Amperit powders projected at a distance of 90 mm provided better cohesion and a more dense microstructure. However, the choice of the spraying distance of 120 mm was defined to manufacture composite structures, which allowed more stability in the plasma jet and enabled large metal particles to be mixed with ceramics. To develop hard and wear-resistant coatings, alumina and 316SS were mixed with different addition rates by volume (Al2O3–5 vol.%316SS and Al2O3–25 vol.%316SS) and fed through a single injection port. Composite coatings include porosity and unmolten particles in a lamellar microstructure. The addition of 316SS powder led to the formation of typical layered structure due to the effect of viscosity and different densities of the two particles. These coatings were investigated by different tests to evaluate microhardness, cohesion, and fracture values of such materials. Despite the significant decrease in the microhardness values, the 316SS particle addition demonstrates an improvement in the toughness and crack resistance.

scholarly journals Nanostructured Multilayer Composite Coatings for Cutting Tools

2020 ◽  
Author(s):  
Sergey Grigoriev ◽  
Alexey Vereschaka ◽  
Marina Volosova ◽  
Caterina Sotova ◽  
Nikolay Sitnikov ◽  
...  
Keyword(s):  
Composite Coatings ◽  
Cutting Tools ◽  
Theoretical Background ◽  
Multilayer Composite ◽  
Wear Resistant ◽  
Wear Resistant Coatings ◽  
Ceramic Tools ◽  
Operation Conditions ◽  
Resistant Layer ◽  
Nanostructured Multilayer Composite Coatings

The chapter deals with the specific features concerning the application of wear-resistant coatings to improve the performance properties of ceramic cutting tools. The paper discusses the theoretical background associated with the specific operation conditions and wear of ceramic cutting tools and influencing the choice of the compositions and structures of wear-resistant coatings. The studies were focused on the application of the Ti-(Ti,Al)N-(Zr,Nb,Ti,Al)N multilayer composite coating with a nanostructured wear-resistant layer, as well as the (Cr,Al,Si)N–(DLC–Si)–DLC–(DLC–Si) and (Cr,Al,Si)N–DLC composite coatings in order to improve the cutting properties of ceramic tools. The chapter presents the results of the comparative cutting tests for the tools with the coatings under study, uncoated tools, and tools with the Ti-(Ti,Al)N commercial coating. The wear mechanisms typical for ceramic cutting tools with coatings of various compositions have been investigated.

Protective coatings of alloy of the Ni–Cr–Mo system with a wide range of operating temperatures

2021 ◽  
pp. 74-79
Author(s):  
T. I. Bobkova ◽  
R. Yu. Bystrov ◽  
A. F. Vasilev ◽  
A. M. Makarov ◽  
B. V. Farmakovsky
Keyword(s):  
Protective Coatings ◽  
Experimental Studies ◽  
Wear Resistant ◽  
Wear Resistant Coatings ◽  
Wide Range ◽  
Operating Temperatures

This article presents the results of experimental studies of alloys of the Ni–Cr–Mo–Be–Re–Zr–Hf– Nb system for creating functional wear-resistant coatings on their basis by the method of microplasma spraying. The coating works efficiently in a wide range of positive (up to 1100°C) and negative (up to minus 196°C) temperatures.

Investigations of Wettability of Wear Resistant Coatings Produced by Atmospheric Plasma Spraying

2017 ◽  
Vol 270 ◽  
pp. 230-235 ◽  
Author(s):  
Pavel Komarov ◽  
Ladislav Čelko ◽  
David Jech ◽  
Martin Papula ◽  
Karel Slámečka ◽  
...  
Keyword(s):  
Contact Angle ◽  
Plasma Spraying ◽  
Liquid Droplet ◽  
Critical Role ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
Metallographic Analysis ◽  
Water Contact ◽  
Wear Resistant ◽  
Wear Resistant Coatings

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.

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