Simulation of PYSZ particle impact and solidification in atmospheric plasma spraying coating process

Este é um artigo publicado em acesso aberto (Open Access) sob a licença Creative Commons Attribution Non-Commercial, que permite uso, distribuição e reprodução em qualquer meio, sem restrições desde que sem fins comerciais e que o trabalho original seja corretamente citado. Abstract: This work aims to study the effect of preheating and single and multiple passes on the degree of porosity, oxidation and microhardness in the coating process obtained by wire flame thermal spraying. The air oxidation of sprayed particles after splat affects the performance for duplex stainless steel AF2209 deposited by wire flame thermal spraying on structural steel substrate preheated with torch at different temperatures. The oxide and pore percentage were measured and quantified by optical microscopy with the aid of image analysis software. Images by SEM and the Vickers hardness of oxides and pancakes indicate that oxidation increases with preheating and with the deposition of multiple passes. The results indicate that higher preheaters and the deposition of multiple passes reduce the fragmentation of the particles, but increases the amount of oxides. It is also noted that coating reheating reduces the Vickers mean microhardness of the oxides and pancakes from the single pass condition to the multiple pass condition. Key-words:Oxidation; Duplex stainless steel; Thermal spray; Preheating. IntroduçãoO processo de aspersão térmica chama arame envolve a combustão contínua entre os gases C 2 H 2 + O 2 , liberados através do bocal da tocha e acelerados pelo fluxo de ar comprimido. O arame é alimentado de forma axial ao centro da chama e continuamente fundido pela ponta na forma de partículas líquidas arrancadas e aceleradas pelo fluxo de ar comprimido. Para os processos de aspersão, a proteção atmosférica tem uma importância significativa, pois durante a deposição de revestimentos um elevado grau de oxidação significa a remoção dos elementos em solução sólida da liga metálica [1,2].No processo de aspersão térmica chama arame a oxidação pode ocorrer no bico da pistola, durante o trajeto e após a deposição, afetando a morfologia no empilhamento das panquecas e o contato entre estas. Os óxidos formados podem influenciar a composição

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“…Concluída a deposição, a camada aspergida fica exposta por prolongado tempo ao ar ambiente, resfriando até a temperatura ambiente [8,9].…”

Section: Figuraunclassified

Efeito do Pré-aquecimento e de Único e Múltiplos Passes no Grau de Porosidade, Oxidação e Microdureza de um Revestimento de Aço Inoxidável Duplex Depositado por Aspersão Térmica Chama Arame

Silva

Paredes

2016

Soldag. insp.

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“…Therefore, it is preferred to obtain a stable, continuous, slow-growing, and uniform TGO layer with strong adherent ability at the TC/BC interface. The TGO evolution is susceptible to the surface conditions of the MCrAlY coating, including the surface feature, microstructure, coating composition, and residual stress, which are dependent on the preparation process. , The air plasma spray (APS) technique has been widely employed to deposit TBCs, especially the MCrAlY bond coat, because of the advantages associated with low cost, good practicality, and high efficiency. , However, the as-sprayed coatings exhibit typical layered and porous structures, microcracks, a rough surface, and inhomogeneities, which dramatically affect the service life of TBCs, particularly on the growth of the TGO layer. Therefore, an effective method to conquer these thermally sprayed defects of the MCrAlY coating will be beneficial for the lifetime prediction of the TBC system.…”

Section: Introductionmentioning

confidence: 99%

Thermal Cycling Behavior of Thermal Barrier Coatings with MCrAlY Bond Coat Irradiated by High-Current Pulsed Electron Beam

Cai

Guan

et al. 2016

ACS Appl. Mater. Interfaces

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Microstructural modifications of a thermally sprayed MCrAlY bond coat subjected to high-current pulsed electron beam (HCPEB) and their relationships with thermal cycling behavior of thermal barrier coatings (TBCs) were investigated. Microstructural observations revealed that the rough surface of air plasma spraying (APS) samples was significantly remelted and replaced by many interconnected bulged nodules after HCPEB irradiation. Meanwhile, the parallel columnar grains with growth direction perpendicular to the coating surface were observed inside these bulged nodules. Substantial Y-rich AlO bubbles and varieties of nanocrystallines were distributed evenly on the top of the modified layer. A physical model was proposed to describe the evaporation-condensation mechanism taking place at the irradiated surface for generating such surface morphologies. The results of thermal cycling test showed that HCPEB-TBCs presented higher thermal cycling resistance, the spalling area of which after 200 cycles accounted for only 1% of its total area, while it was about 34% for APS-TBCs. The resulting failure mode, i.e., in particular, a mixed delamination crack path, was shown and discussed. The irradiated effects including compact remelted surface, abundant nanoparticles, refined columnar grains, Y-rich alumina bubbles, and deformation structures contributed to the formation of a stable, continuous, slow-growing, and uniform thermally grown oxide with strong adherent ability. It appeared to be responsible for releasing stress and changing the cracking paths, and ultimately greatly improving the thermal cycling behavior of HCPEB-TBCs.

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“…Thermal spraying technologies are widely used to produce various coatings with high deposition rate for structural and functional applications, which certainly give much greater flexibility and could easily be adapted to deposit coatings onto components surface having very different geometries . It allows using the widest range of available materials to obtain different coatings for the application in many industrial fields, such as wear resistance coatings, thermal barrier coatings, and resistance corrosive environment coatings .…”

Section: Introductionmentioning

confidence: 99%

Complex Permittivity and Microwave‐Absorbing Properties of Fe/Al₂O₃ Coatings by Air Plasma Spraying Technique

Zhao

Luo

Zhou

et al. 2013

Int J Applied Ceramic Tech

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The Fe/Al 2 O 3 coatings for application as microwave absorbers were deposited by air plasma spraying (APS). The morphologies of powders and cross-section of coatings were characterized by scanning electron microscope (SEM). The investigations of electrical conductivity and complex permittivity properties of coatings were performed. The real part (e′) of permittivity increases with increasing Fe volume fraction, which is attributed to the space charge polarization, and the imaginary part (e″) also increases which is ascribed to the increasing electrical conductivity result from the formation of Fe conductive network. The effect of Fe content on dielectric properties and the corresponding mechanisms are analyzed. By measuring the microwave absorption properties of the Fe/Al 2 O 3 coatings as a single-layer absorbers, it was find that the reflection loss varies with the changes of thickness and Fe content, due to the deviation of impedance-matching condition.

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Simulation of PYSZ particle impact and solidification in atmospheric plasma spraying coating process

Cited by 25 publications

References 15 publications

Efeito do Pré-aquecimento e de Único e Múltiplos Passes no Grau de Porosidade, Oxidação e Microdureza de um Revestimento de Aço Inoxidável Duplex Depositado por Aspersão Térmica Chama Arame

Efeito do Pré-aquecimento e de Único e Múltiplos Passes no Grau de Porosidade, Oxidação e Microdureza de um Revestimento de Aço Inoxidável Duplex Depositado por Aspersão Térmica Chama Arame

Thermal Cycling Behavior of Thermal Barrier Coatings with MCrAlY Bond Coat Irradiated by High-Current Pulsed Electron Beam

Complex Permittivity and Microwave‐Absorbing Properties of Fe/Al₂O₃ Coatings by Air Plasma Spraying Technique

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Simulation of PYSZ particle impact and solidification in atmospheric plasma spraying coating process

Cited by 25 publications

References 15 publications

Efeito do Pré-aquecimento e de Único e Múltiplos Passes no Grau de Porosidade, Oxidação e Microdureza de um Revestimento de Aço Inoxidável Duplex Depositado por Aspersão Térmica Chama Arame

Efeito do Pré-aquecimento e de Único e Múltiplos Passes no Grau de Porosidade, Oxidação e Microdureza de um Revestimento de Aço Inoxidável Duplex Depositado por Aspersão Térmica Chama Arame

Thermal Cycling Behavior of Thermal Barrier Coatings with MCrAlY Bond Coat Irradiated by High-Current Pulsed Electron Beam

Complex Permittivity and Microwave‐Absorbing Properties of Fe/Al2O3 Coatings by Air Plasma Spraying Technique

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Product

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Complex Permittivity and Microwave‐Absorbing Properties of Fe/Al₂O₃ Coatings by Air Plasma Spraying Technique