Microstructure Peculiarities of Intermetallic and Composite Coatings

Coatings were obtained by the method of electrospark deposition (ESD), using Ni-Al intermetallic alloys, steel having been used as cathodes. The structure of samples preliminarily, coated with nickel aluminides of various phase compositions (NiAl, Ni3Al), was investigated. In addition to the indicated anode materials, a complex alloyed metal matrix alloy obtained by the method of self-propagating high-temperature synthesis, was used. It was established that the coating microstructure consisted of columnar crystallites, vertically oriented to the cathode surface. X-ray microanalysis of the transverse sections showed a change in the composition of crystallites along their height. It was found that the content of the cathode components decreased from the surface of the sample to the upper part of its coating, however, the content of the anode components increased. The revealed regularities indicate the fact that the coating structure obtained at ESD, was formed through the stage of liquid-phase mixing, which explained high coating adheasion. The mechanisms of structure formation of both single-layer and two-layer coatings proved to be identical.

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Characterization of Cr2O3-TiO2-CaF2 Coatings Using Plasma Spray Process

Thermal Spray 1997: Proceedings from the United Thermal Spray Conference ◽

10.31399/asm.cp.itsc1997p0713 ◽

1997 ◽

Author(s):

A.Ph. Ilyuschenko ◽

N.I. Shipica ◽

P.A. Vityaz ◽

A.A. Yerstak ◽

A.Y. Beliaev

Keyword(s):

Wear Resistance ◽

Plasma Spray ◽

Composite Coatings ◽

Wear Testing ◽

Material System ◽

Composite Powders ◽

Spray Coatings ◽

Spray Process ◽

Plasma Spray Coatings ◽

High Temperature Synthesis

Abstract This paper presents the results of a study on the wear resistance of plasma spray coatings made from Cr2O3-TiO2-CaF2 powders. The composite powders used were produced by self-propagating high temperature synthesis. They were then applied under various conditions in order to optimize the material system, spray process, and application procedures. Based on the results of microstructural examination and wear testing, the thermally sprayed composite coatings have excellent wear resistance, good adhesion, and are self-lubricating at high temperatures.

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Development of Metal-Ceramic-Lubricant Composite Coatings Obtained by Cold Spray for Tribological Applications in the Automotive Industry

10.31399/asm.cp.itsc2021p0561 ◽

2021 ◽

Author(s):

G. Garcin ◽

F. Delloro ◽

M. Jeandin ◽

J-F. Hochepied ◽

C. Grente ◽

...

Keyword(s):

Automotive Industry ◽

Composite Coatings ◽

Solid Lubricants ◽

Friction Reduction ◽

Hard Particles ◽

Wide Range ◽

Metal Ceramic ◽

Coating Microstructure ◽

Steel Substrates ◽

The Relationship

Abstract One of the main levers to reduce CO2 emissions in cars and trucks is mass and friction reduction, which is often achieved through the use of special coatings. The aim of the present work was to develop metal-ceramic-lubricant composite coatings with the best combination of wear, seizure, fatigue, and thermal resistance. Metal-based coatings incorporating hard particles and solid lubricants were cold sprayed onto steel substrates and the relationship between coating microstructure and tribology was studied. To meet the demanding tribological requirements of heavily loaded engines, the interfaces between the different components were optimized by selecting appropriate feedstock powders and assessing a wide range of process parameters. Alumina-reinforced bronze composite coatings were made from powders with different morphologies. Aggregated ceramic powders were found to be more beneficial in terms of wear than massive powders, and graphite was found to be effective for reducing seizure.

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Study of Damage Mechanisms in Cold-Sprayed 316L-Matrix Composite Coatings Using Novel Impact-Sliding Testing

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.922.452 ◽

2014 ◽

Vol 922 ◽

pp. 452-462 ◽

Cited By ~ 1

Author(s):

R. Maestracci ◽

N. Fabrègue ◽

M. Jeandin ◽

G. Bouvard ◽

M. Messaadi ◽

...

Keyword(s):

Cold Spray ◽

High Performance ◽

Composite Coatings ◽

Industrial Applications ◽

Damage Mechanisms ◽

Coating Composition ◽

Before And After ◽

Coating Microstructure ◽

Service Conditions ◽

Sliding Test

Cold spray is now well recognized as one of the most powerful and efficient coating process because it is cost-attractive and “green”. However, this process still shows limitations to achieve coatings for highly-demanding service conditions such as those required in certain automotive and/or aircraft applications. Beyond these limitations, cold spray is expected to compete with conventional P/M routes.The present work therefore focussed on the study of damage mechanisms in cold-sprayed AISI 316L and 316L-matrix–Cu composites coatings due to high-loading conditions. Different damage mechanisms could occur depending on the content of Cu particle addition, due to changes in the response of the microstructure to the loading. These mechanisms were studied using the newly-developed “impact-sliding” test. In this test, a steel ball impacts the coating surface at a given frequency, with a fixed angle. The influence of major testing parameters was investigated.Microstructures before and after testing were studied using optical microscopy, scanning electron microscopy (SEM), and microprobe analysis in addition to 3D optical profilometry of impacted areas. Damage mechanisms were seen to be of two types, i.e. plastic deformation and wear. These resulted in decohesion of splats, formation of wear debris and formation of a layer with a tribologically-transformed structure (TTS) at the contact surface.Results showed that cold spray could be claimed to be suitable for the achievement of high-performance coatings for industrial applications provided that the coating microstructure can be controlled. This could be done using a composite approach to the coating composition.

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Tribocorrosion characteristics of Ti6Al4V-TiB-TiN in-situ composite coatings prepared using plasma spraying

Journal of Composite Materials ◽

10.1177/0021998320981129 ◽

2020 ◽

pp. 002199832098112

Author(s):

Akrity Anand ◽

Mitun Das ◽

Biswanath Kundu ◽

Vamsi Krishna Balla ◽

Subhadip Bodhak ◽

...

Keyword(s):

Plasma Spraying ◽

Strong Influence ◽

Dominant Role ◽

Composite Coatings ◽

High Hardness ◽

Alloy Composite ◽

Material Loss ◽

In Situ Composite ◽

Coating Microstructure

Ti6Al4V alloy composite coatings in-situ reinforced with TiB-TiN were deposited on Ti substrate using plasma spraying. Influence of plasma power (50 and 60 kW) and deposition speed (40 and 50 mm/s) on coating microstructure and bio-tribocorrosion performance was analyzed. Process parameters found to have strong influence on the tribocorrosion behavior and the material loss/damage of these coatings was found to be significantly less than that of Ti substrate. However, corrosion played a dominant role in affecting the wear and overall damage of all materials. Present in-situ composite coatings reinforced TiB-TiN exhibited superior tribocorrosion resistance than Ti substrate as a result of their high hardness and non-passivating nature.

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Improvement of microstructure and properties of Ni–Al2O3 composite coating via jet electrodeposition

International Journal of Modern Physics B ◽

10.1142/s0217979220502434 ◽

2020 ◽

Vol 34 (27) ◽

pp. 2050243

Author(s):

Hui Fan ◽

Jie Jiang ◽

Yangpei Zhao ◽

Shankui Wang ◽

Zhijing Li

Keyword(s):

Wear Rate ◽

Surface Morphology ◽

Composite Coating ◽

Process Parameters ◽

Current Density ◽

Composite Coatings ◽

Coating Structure ◽

Mechanical And Tribological Properties ◽

Al2o3 Composite ◽

Jet Electrodeposition

Ni–Al2O3 composite coatings were prepared with a modified Watt’s bath by using jet electrodeposition method. As the key process parameter, current density and the addition of Al2O3 nanoparticles in electrolyte were studied about the effect on the surface morphology and co-deposition of Al2O3 nanoparticles of composite coating. The mechanical and tribological properties of the composite coating were also tested. The results show that properly increasing the current density and Al2O3 addition can increase the co-deposition of nanoparticles in the coating and promote the formation of a dense and refined coating structure. Using the optimized process parameters of current density (300 A/dm2) and Al2O3 addition (30 g/L), the co-deposition of Al2O3 in the composite coating can reach a maximum of 13.1 at.%. The hardness of the coating reaches the peak at 623 HV. The wear rate of the composite coating is also greatly reduced with optimized parameters.

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Effect of Annealing Treatment on the Structure and Microhardness of Cold-Sprayed Nanostructured FeAl/WC Composite Coating

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.373-374.73 ◽

2008 ◽

Vol 373-374 ◽

pp. 73-76 ◽

Cited By ~ 1

Author(s):

Hong Tao Wang ◽

Guan Jun Yang ◽

Chang Jiu Li ◽

Cheng Xing Li

Keyword(s):

Solid Solution ◽

Annealing Time ◽

Composite Coatings ◽

Annealing Treatment ◽

Nanocrystalline Structure ◽

Intermetallic Phases ◽

Coating Structure ◽

Intermetallic Composite ◽

Sprayed Coating ◽

Sprayed Coatings

Nanostructured FeAl/WC intermetallic composite coatings were prepared by cold spaying of the ball-milled powders. The effect of annealing on the coating structure and microhardness was examined. It was found that the nanocrystalline structure of the milled feedstock was retained in the cold sprayed coatings. The FeAl intermetallic phases were formed from the milled Fe(Al) solid solution during the post-spraying annealing at 550oC. The microhardness of the as-sprayed coating was about 680HV0.1 and it decreased a little with increasing the annealing time at 550oC.

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Fracture in single-layer zirconia (YSZ)–bond coat alloy (NiCoCrAlY) composite coatings under thermal shock

Acta Materialia ◽

10.1016/j.actamat.2003.09.029 ◽

2004 ◽

Vol 52 (2) ◽

pp. 455-465 ◽

Cited By ~ 37

Author(s):

Sudarshan Rangaraj ◽

Klod Kokini

Keyword(s):

Thermal Shock ◽

Bond Coat ◽

Composite Coatings ◽

Single Layer ◽

Bond Coat Alloy

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A review on corrosion protection with single-layer, multilayer, and composites of graphene

Corrosion Reviews ◽

10.1515/corrrev-2017-0016 ◽

2018 ◽

Vol 36 (2) ◽

pp. 155-225 ◽

Cited By ~ 6

Author(s):

András Gergely

Keyword(s):

Corrosion Protection ◽

Composite Coatings ◽

Single Layer ◽

Comprehensive Overview ◽

Environmental Friendliness ◽

Thin Carbon ◽

Graphene Derivatives ◽

Research Findings ◽

And Performance ◽

Protection Of Metals

AbstractIn this review, most of the works are attempted to cover about corrosion protection of metals with molecular-tight atomic thin carbon layers of all sorts of graphene derivatives from the very beginning to the latest theoretical and experimental research findings, so as engineering achievements in the field up to date. Although high and tuneable electrical conductivity of graphene is the main feature exploited in majority of the applications such as catalysis, photocatalysis, electrocatalysis, low electrical but high chemical resistivity electrodes in batteries, and ultracapacitors, corrosion protection of metals favours the opposite – good physical separation and electrical insulation. Both of the latter ones lead to durable excellent protection, which can only be ensured by special design and implementation. Thus, the milestones of major hardships both on theoretical and practical sides are delineated similarly as utmost developments in circumventing all problems with an aim to ensure timely transfer from the research phase to successful industry utilisations. Relying on numerous works, this paper gives a comprehensive overview in the subjects of preparation, modification, and use of multiple sorts of graphene in the forms of neat, combined layers, and composite coatings on numerous metals. All performance parameters are given in detail. Chronological order of the article serves the purpose to give the reader a clear picture and an important clue on viability of strategies in the aspects of environmental friendliness, attainable maximum durability, and performance of corrosion protection with graphene films, as well as further advancements in the field expected to occur in the near future.

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Influence of Modifiers on the Structure and Properties of Composite Coatings System Ti-B-Fe

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.880.80 ◽

2014 ◽

Vol 880 ◽

pp. 80-87

Author(s):

Nina K. Galchenko ◽

Ksenia A. Kolesnikova ◽

S.I. Belyuk ◽

B.V. Dampilon

Keyword(s):

Electron Beam ◽

Composite Coatings ◽

Reactive Diffusion ◽

Amorphous Boron ◽

Structure And Properties ◽

Coating Structure ◽

Equilibrium Crystallization ◽

Structure Degradation ◽

Boride Coatings ◽

Two Factors

The paper studies how microalloying with amorphous boron (Bam) and zirconia (ZrO2) influences the structure and properties of boride coatings. Two factors are found to strongly affect the structure and phase formation in composite coatings produced by electron beam surfacing, especially when using thermoreactive powders: (i) high reactive diffusion between the composite and substrate components, which causes the coating structure degradation, and (ii) slight deviations from phase concentrations and equilibrium crystallization, which give rise to such nonequilibrium phases in the coating structure under the electron beam as ferroboron, ferrotitanium and binary eutectics.

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