A Novel Strategy for Depositing Dense Self-fluxing Alloy Coatings with Sufficiently Bonded Splats by One-Step Atmospheric Plasma Spraying

Dong, Xiaoxin; Luo, Xiao-Tao; Zhang, Shan-Lin; Li, Chang‐Jiu

doi:10.1007/s11666-019-00943-4

Cited by 22 publications

(25 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It was generally observed that the particle temperature will decrease with the increase in the spray distance during plasma spraying (Ref 27 ). In this study, for M-powder and L-powder, it was observed that the particle temperature first increased up to a spray distance of 90 mm from 60 mm and then tended to decrease when the spray distance was increased further from 90 mm to 150 mm.…”

Section: Resultsmentioning

confidence: 99%

Effect of Powder Particle Size and Spray Parameters on the Ni/Al Reaction During Plasma Spraying of Ni-Al Composite Powders

et al. 2021

Self Cite

View full text Add to dashboard Cite

It was known for long that Ni-Al composite powders can be used to deposit self-bonding coating as a bond coat for common ceramic coatings due to the exothermic reaction between Ni and Al. However, it was found that with commercial Ni-Al composite powders with a large particle size, it is difficult to ignite the self-propagating reaction between Ni and Al to form Ni-Al intermetallics by plasma spraying. In this study, Ni-Al composite powder particles of different sizes were used to prepare Ni-Al intermetallics-based coatings by plasma spraying. The dependencies of the exothermic reaction between Ni and Al and the coating microstructure on powder particle size and spray parameters were investigated. The phase composition, microstructure, porosity and oxide content of the coatings were characterized by x-ray diffraction, scanning electron microscope and image analyzing. The results show that particle size of Ni-Al composite powders is the dominant factor controlling the exothermic reaction for the formation of Ni-Al intermetallics during plasma spraying. When the powders larger than about 50 lm are used, the reaction forming aluminide cannot complete even by heating of plasma flame generated at high plasma arc power. However, when smaller powders less than 50 lm are used, the exothermic reaction can completely occur rapidly in plasma spraying, contributing to heating of Ni-Al droplets to the highest temperature for development of the self-bonding effect. The positive relationship between molten droplet temperature and tensile adhesive strength of the resultant coatings is recognized to confirm the contribution of high droplet temperature to the adhesive or cohesive strength. Keywords Ni-clad Al Á powder particle size Á exothermic reaction Á Ni-Al intermetallics Á plasma spraying Á selfbonding This article is an invited paper selected from abstracts submitted for the 2020 International Thermal Spray Conference, ITSC2020, that was to be held from June 10-12, 2020, in Vienna, Austria. The conference was cancelled due to the coronavirus (COVID-19) pandemic. The paper has been expanded from the planned presentation.

show abstract

Section: Resultsmentioning

confidence: 99%

Effect of Powder Particle Size and Spray Parameters on the Ni/Al Reaction During Plasma Spraying of Ni-Al Composite Powders

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…The evolution of the interface temperature between spreading molten metal and substrate when a molten metal droplet impacts on a metal can be estimated by a simple one dimensional heat transfer model through supposing a thin layer of molten metal is instantaneously brought on a flat metal surface [6]. For Ni-based alloy droplets at different temperatures, the simulation yielded that only when the droplet temperature is higher than about 2400 o C [8], after its impact, leading to the coverage of a thin layer of overheated molten liquid on a substrate, the maximum temperature of the substrate surface can be heated to a temperature higher than its melting point.…”

Section: Development Of Dense Ni-based Metal Coating Via Creating Of Ultra-high Temperature Dropletsmentioning

confidence: 99%

“…The effect of droplet temperature on the simulated temperature evolution at the interface between molten splat and solid substrate for Ni-based alloy [8].…”

Section: Figurementioning

confidence: 99%

Novel Strategy for Developing Bulk-Like Dense Metallic Coatings by Plasma Spraying

Dong

Zhang

et al. 2021

Thermal Spray 2021: Proceedings From the International Thermal Spray Conference

Self Cite

View full text Add to dashboard Cite

Thermal spray coatings are widely used to protect materials from corrosion, wear, and oxidation, but they have yet to reach their full potential because of porosity limitations and the detrimental effects of oxidation on interlamellar bonding. This paper investigates an atmospheric plasma spraying process that deposits oxide-free dense metallic coatings with well bonded lamellae. The process produces ultrahigh temperature metallic droplets, up to 2650 °C, using specially designed powders that are deoxidized in-flight through the evaporation or gasification of oxides. The impact of these oxide-free ultrahigh temperature droplets has a spreading-fusing, self-metallurgical bonding effect resulting in fully dense bulk-like metallic coatings. Various coating materials, including NiCrMo, 304SS-Mo, NiCrBSi, and Al, are investigated, demonstrating the versatility of the new technique.

show abstract

“…The usual ways of subsequent remelting are by flame, laser, and in the furnace. However, in the investigations presented in Reference [7][8][9][10][11], NiCrBSi coatings were obtained by one-step process. In investigation Reference [9], the coatings were deposited by plasma spraying system with modified nozzle for enhancing particle heating with an internal powder injector.…”

Section: Introductionmentioning

confidence: 99%

“…However, in the investigations presented in Reference [7][8][9][10][11], NiCrBSi coatings were obtained by one-step process. In investigation Reference [9], the coatings were deposited by plasma spraying system with modified nozzle for enhancing particle heating with an internal powder injector. The used system enabled higher particle temperatures thus providing a self-fusing effect between molten droplet and previous splat, i.e., the additional post-spray fusing was avoided in that way.…”

Section: Introductionmentioning

confidence: 99%

Modeling and Optimization in Investigating Thermally Sprayed Ni-Based Self-Fluxing Alloy Coatings: A Review

et al. 2020

View full text Add to dashboard Cite

In investigating thermally sprayed Ni-based self-fluxing alloy coatings, widely applied under conditions of wear, corrosion, and high temperatures, designed experiments and statistical methods as a basis for modeling and optimization have become an important tool in making valid and comparable conclusions. Therefore, this paper gives an overview of investigating Ni-based self-fluxing alloy coatings deposited by thermal spraying by the use of designed experiments and statistical methods. The investigation includes the period of the last two decades and covers the treatments of flame spraying, high-velocity oxy/air fuel spraying, plasma spraying, plasma-transferred arc welding, and laser cladding. The main aim was to separate input variables, as well as measured responses, and to point out the importance of correct application of statistical design of experiment. After the review of the papers, it was concluded that investigators have used the process knowledge to analyze and interpret the results of the statistical analysis of experimental data, which is in fact the best way of using the design of experiment in every research. Nevertheless, more attention should be given to correct planning and conducting the experiments to derive the models suitable for the prediction of measured response and which could be an appropriate input for single- or multi-objective optimization.

show abstract

A Novel Strategy for Depositing Dense Self-fluxing Alloy Coatings with Sufficiently Bonded Splats by One-Step Atmospheric Plasma Spraying

Cited by 22 publications

References 35 publications

Effect of Powder Particle Size and Spray Parameters on the Ni/Al Reaction During Plasma Spraying of Ni-Al Composite Powders

Effect of Powder Particle Size and Spray Parameters on the Ni/Al Reaction During Plasma Spraying of Ni-Al Composite Powders

Novel Strategy for Developing Bulk-Like Dense Metallic Coatings by Plasma Spraying

Modeling and Optimization in Investigating Thermally Sprayed Ni-Based Self-Fluxing Alloy Coatings: A Review

Contact Info

Product

Resources

About