Phase Structure Evolution of the Fe-Al Arc-Sprayed Coating Stimulated by Annealing

The article presents the results of research on the structural evolution of the composite Fe-Al-based coating deposited by arc spray with initial low participation of in situ intermetallic phases. The arc spraying process was carried out by simultaneously melting two different electrode wires, aluminum and low alloy steel (98.6 wt.% of Fe). The aim of the research was to reach protective coatings with a composite structure consisting of a significant participation of FexAly as intermetallic phases reinforcement. Initially, synthesis of intermetallic phases took place in situ during the spraying process. In the next step, participation of FexAly fraction was increased through the annealing process, with three temperature values, 700 °C, 800 °C, and 900 °C. Phase structure evolution of the Fe-Al arc-sprayed coating, stimulated by annealing, has been described by means of SEM images taken with a QBSD backscattered electron detector and by XRD and conversion electron Mössbauer spectroscopy (CEMS) investigations. Microhardness distribution of the investigated annealed coatings has been presented.

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Structure and Selected Properties of Arc Sprayed Coatings Containing In-Situ Fabricated Fe-Al Intermetallic Phases

Metals ◽

10.3390/met8121059 ◽

2018 ◽

Vol 8 (12) ◽

pp. 1059 ◽

Cited By ~ 10

Author(s):

Tomasz Chmielewski ◽

Piotr Siwek ◽

Marcin Chmielewski ◽

Anna Piątkowska ◽

Agnieszka Grabias ◽

...

Keyword(s):

Protective Coatings ◽

Composite Coatings ◽

Thermal Spraying ◽

Intermetallic Phases ◽

Arc Spraying ◽

Coating Materials ◽

Two Phases ◽

Sprayed Coatings ◽

Spraying Process

The paper presents the results of research on the production by means of arc spraying of composite coatings from the Fe-Al system with participation of in-situ intermetallic phases. The arc spraying process was carried out by simultaneously melting two different electrode wires, aluminum and steel. The aim of the research is to create protective coatings with a composite structure with a significant participation of FexAly as an intermetallic phases reinforcement. The synthesis of intermetallic phases takes place during the (in-situ) spraying process. Currently most coatings involving intermetallic phases are manufactured by different thermal spraying methods using coating materials in the form of prefabricated powders containing intermetallic phases. The obtained results showed the local occurrence of intermetallic phases from the Fe-Al system, and the dominant components of the structure have two phases, aluminum solid solutions in iron and iron in aluminum. The participation of intermetallic phases in the coating is relatively low, but its effect on the properties of the coating material is significant.

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Properties of Metal-Sprayed Coating Produced by Electric-Arc-Spraying Process

Indian Welding Journal ◽

10.22486/iwj.v3i2.150258 ◽

1971 ◽

Vol 3 (2) ◽

pp. 61

Author(s):

M. D. Modi

Keyword(s):

Electric Arc ◽

Arc Spraying ◽

Sprayed Coating ◽

Spraying Process

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In Situ X-ray Measurements to Follow the Crystallization of BaTiO3 Thin Films during RF-Magnetron Sputter Deposition

Applied Sciences ◽

10.3390/app11198970 ◽

2021 ◽

Vol 11 (19) ◽

pp. 8970

Author(s):

Peter Walter ◽

Markus Ilchen ◽

JanTorben Roeh ◽

Wiebke Ohm ◽

Christian Bonar Zeuthen ◽

...

Keyword(s):

Thin Film ◽

Thin Films ◽

Film Growth ◽

Structural Evolution ◽

Thin Film Growth ◽

Structure Evolution ◽

Special Focus ◽

Time Resolved ◽

X Ray

Here, we report on adding an important dimension to the fundamental understanding of the evolution of the thin film micro structure evolution. Thin films have gained broad attention in their applications for electro-optical devices, solar-cell technology, as well storage devices. Deep insights into fundamental functionalities can be realized via studying crystallization microstructure and formation processes of polycrystalline or epitaxial thin films. Besides the fundamental aspects, it is industrially important to minimize cost which intrinsically requires lower energy consumption at increasing performance which requires new approaches to thin film growth in general. Here, we present a state of the art sputtering technique that allows for time-resolved in situ studies of such thin film growth with a special focus on the crystallization via small angle scattering and X-ray diffraction. Focusing on the crystallization of the example material of BaTiO3, we demonstrate how a prototypical thin film forms and how detailed all phases of the structural evolution can be identified. The technique is shaped to enable a versatile approach for understanding and ultimately controlling a broad variety of growth processes, and more over it demonstrate how to in situ investigate the influence of single high temperature sputtering parameters on the film quality. It is shown that the whole evolution from nucleation, diffusion adsorption and grain growth to the crystallization can be observed during all stages of thin film growth as well as quantitatively as qualitatively. This can be used to optimize thin-film quality, efficiency and performance.

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Use of pulsed spray airflow for electric arc spraying of different types of wires

Technology audit and production reserves ◽

10.15587/2706-5448.2021.235405 ◽

2021 ◽

Vol 3 (1(59)) ◽

pp. 23-27

Author(s):

Vyacheslav Royanov ◽

Irina Zakharova

Keyword(s):

Chemical Composition ◽

Adhesion Strength ◽

Chemical Elements ◽

Air Flow ◽

Arc Spraying ◽

Capital Costs ◽

Burn Out ◽

Sprayed Coating ◽

Spraying Process

The object of research is the control of the process of formation of a spraying air flow and the transfer of particles of liquid metal from electrodes during arc spraying. One of the problem areas of the arc spraying process is the oxidation of the sprayed metal particles by the oxygen of the air flow during their transportation to the sprayed surface. This leads to the formation of a sufficiently large amount of oxides of chemical elements, which significantly deteriorate the adhesion strength and burn out alloying elements that are necessary to obtain a wear-resistant and corrosion-resistant coating. The suitability and durability of coatings during use depends on the strength of adhesion to the substrate. In the course of the study, methods were used to determine the adhesion strength of the coating to the base – the Steffens method and methods for studying the microstructure of coatings were taken as the basis. The data was processed and dependencies were plotted. The proposed method makes it possible to improve the quality of the resulting coating in terms of such an indicator as improvements in chemical composition. And also to influence the chemical composition by controlling the process of transfer of molten metal using a pulsating air flow. The obtained results of approbation of the method allow us to consider it effective, as evidenced by the quality of the obtained coatings. This is due to the fact that the correctness of the formulation and solution of the problem provided adequate results. In contrast to the existing methods, the proposed one makes it possible to significantly influence the amount of harmful oxygen involved in the formation of a sprayed coating, which makes it possible to obtain a sprayed layer with the required performance characteristics. And also allows to improve its quality without significant capital costs. In addition, the issues of resource and energy saving are being addressed, since the burnout of chemical elements decreases and the air consumption during arc metallization decreases. To solve this problem, a simple design of the pulsator is proposed, which provides the ability to control the spray flow by adjusting the level of overlapping of the holes.

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STRUCTURAL EVOLUTION OF EXCEPTIONALLY IRON-DEFICIENT HEMATITE NANOCRYSTALS AS OBSERVED BY IN SITU SYNCHROTRON X-RAY DIFFRACTION

10.1130/abs/2019am-337360 ◽

2019 ◽

Author(s):

Si Athena Chen ◽

◽

Peter Heaney ◽

Jeffrey E. Post ◽

Peter J. Eng ◽

...

Keyword(s):

Structural Evolution ◽

X Ray Diffraction ◽

X Ray ◽

Iron Deficient

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Dependence of the intrinsic phase structure of Bi2O3 catalysts on photocatalytic CO2 reduction

Catalysis Science & Technology ◽

10.1039/d1cy00286d ◽

2021 ◽

Vol 11 (6) ◽

pp. 2021-2025

Author(s):

Liujin Wei ◽

Guan Huang ◽

Yajun Zhang

Keyword(s):

Fourier Transform ◽

Infrared Spectroscopy ◽

Fourier Transform Infrared Spectroscopy ◽

Phase Structure ◽

Co2 Reduction ◽

Fourier Transform Infrared ◽

Time Resolved ◽

Dependent Activity

The combination of time-resolved transient photoluminescence with in-situ Fourier transform infrared spectroscopy has been conducted to investigate the intrinsic phase structure-dependent activity of Bi2O3 catalyst for CO2 reduction.

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