Microstructures and Properties of Plasma Surfaced NiCrBSi+WC/Co Layers

Microstructures and properties of plasma surfaced NiCrBSi+20%WC/12Co layer prepared on the die steel (H13) substrate were investigated. The study showed that the interface boundary existed between the layer and substrate. Compared with the typical microstructures of welded joint, the similar columnar grains in the layer perpendicular to the interface line were observed, which were never seen in the plasma sprayed coating. The conclusion could be drawn that the bonding between the NiCrBSi+20%WC/12Co layer and H13 substrate belonged to the metallurgical cohesion. The XRD analysis showed that the main phases in the layer included γ-(Fe, Ni), Cr7BC4, Ni4B3, Cr7C3 and Co7W6, which brought higher strength and higher hardness to the surfaced layer than the H13 substrate.

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Microstructures and Properties of Ni25 and Fe304 Repairing Layers Prepared by Plasma Surfacing

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.466-467.357 ◽

2012 ◽

Vol 466-467 ◽

pp. 357-360

Author(s):

Wen Quan Wang ◽

Bao Sheng Lu ◽

Chang Long Shan

Keyword(s):

Cast Iron ◽

Surface Defects ◽

Nodular Cast Iron ◽

Xrd Analysis ◽

Metal Compounds ◽

Columnar Grains ◽

Plasma Surfacing ◽

Sprayed Coating ◽

Plasma Sprayed ◽

Interface Line

Microstructures and properties of plasma surfaced Ni25 and Fe304 layers prepared on nodular cast iron substrate were investigated. The study showed that the interface boundary existed between the layers and substrate. Compared with typical microstructures of welded joint, the similar columnar grains in the layers perpendicular to the interface line were observed, which were hardly seen in the plasma sprayed coating. The conclusion could be drawn that the bonding between the Ni25 and Fe304 layers and nodular cast iron substrate belonged to the metallurgical cohesion. The XRD analysis showed that the metal compounds such as Ni4B3，Cr7BC4，γ-(Fe, Ni) and Cr7C3were found in the layers. The study demonstrated that the layers had proper strength and hardness to repair the surface defects of the nodular cast iron.

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Investigations of the Fracture of Composites Matrix-Coating Under Tension

Thermal Spray 1998: Proceedings from the International Thermal Spray Conference ◽

10.31399/asm.cp.itsc1998p0867 ◽

1998 ◽

Author(s):

V.E. Panin ◽

V.A. Klimenov ◽

S.V. Panin

Keyword(s):

Steel Matrix ◽

Matrix Composites ◽

Coating Quality ◽

Deformation Stages ◽

The Matrix ◽

Sprayed Coating ◽

Plasma Sprayed

Abstract Deformation stages and specific features were studied by mesomechanical methods under tension of plasma sprayed coating-steel matrix composites. The effect of coating quality on the deformation of the matrix at the mesolevel was revealed. The results obtained make it possible to predict reliability and durability of this kind of coating and of the entire composite.

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Effects of Welding Wire Composition on Microstructure and Mechanical Properties of Welded Joint in Al-Mg-Si Alloy

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.905.44 ◽

2022 ◽

Vol 905 ◽

pp. 44-50

Author(s):

Li Wang ◽

Ya Ya Zheng ◽

Shi Hu Hu

Keyword(s):

Mechanical Properties ◽

Fusion Zone ◽

Heat Affected Zone ◽

Welded Joint ◽

Weld Zone ◽

Xrd Analysis ◽

Metallographic Analysis ◽

Strengthening Effect ◽

Welding Wire ◽

Microstructure And Mechanical Properties

The effects of welding wire composition on microstructure and mechanical properties of welded joint in Al-Mg-Si alloy were studied by electrochemical test, X-ray diffraction (XRD) analysis and metallographic analysis. The results show that the weld zone is composed of coarse columnar dendrites and fine equated grains. Recrystallized grains are observed in the fusion zone, and the microstructure in the heat affected zone is coarsened by welding heat. The hardness curve of welded joint is like W-shaped, the highest hardness point appears near the fusion zone, and the lowest hardness point is in the heat affected zone. The main second phases of welded joints are: matrix α-Al, Mg2Si, AlMnSi, elemental Si and SiO2. The addition of rare earth in welding wire can refine the grain in weld zone obviously, produce fine grain strengthening effect, and improve the electrochemical performance of weld.

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Sealing Treatment of Plasma Sprayed Cr3C2-NiCr/Al2O3-TiO2 Coating by Aluminum Phosphate Sealant Containing Al2O3 Nanoparticles

10.31399/asm.cp.itsc2021p0331 ◽

2021 ◽

Author(s):

Tuan Nguyen Van ◽

Tuan Anh Nguyen ◽

Ha Pham Thi ◽

Ly Pham Thi ◽

Phuong Nguyen ◽

...

Keyword(s):

Corrosion Resistance ◽

Electrochemical Impedance ◽

Aluminum Phosphate ◽

Al2o3 Nanoparticles ◽

Treatment Efficiency ◽

Typical Structure ◽

Sprayed Coating ◽

Plasma Sprayed ◽

Sealing Treatment ◽

Sprayed Coatings

Abstract A typical structure of thermal spray coatings consisted of molten particles, semi-molten particles, oxides, pores and cracks. These factors caused the porosity of sprayed coatings, leading to a great influence on the coating properties, especially their wear-corrosion resistance. In this study, a post-spray sealing treatment of Cr3C2-NiCr/Al2O3-TiO2 plasma sprayed coatings was carried out, then their corrosion properties were evaluated, before and after the treatment. For sealing process, aluminum phosphate (APP) containing aluminum oxide (Al2O3) nanoparticles (~10 nm) was used. The permeability of APP into the sprayed coating was analyzed by scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS). The treatment efficiency for porosity and corrosion resistance of sprayed coatings were evaluated by electrochemical measurements, such as the potentiodynamic polarization and electrochemical impedance spectroscopy. In addition, the wear-corrosion resistance of the sealed coating was examined in 3.5 wt.% NaCl circulation solution containing 0.25 wt.% SiO2 particles. The obtained results showed that APP penetrated deeply through the sprayed coating. The incorporation of Al2O3 nanoparticles into APP sealant enhanced the treatment efficiency of porosity for sprayed coating. The effect of the post-treatment on corrosion protection of the sprayed coating has been discussed.

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Formation of Grain Structures of Thermal Sprayed Nickel Coatings and the Coating Properties

Materials Science Forum ◽

10.4028/www.scientific.net/msf.502.517 ◽

2005 ◽

Vol 502 ◽

pp. 517-0

Author(s):

Kenji Murakami

Keyword(s):

Steel Substrate ◽

Nickel Coatings ◽

Grain Structures ◽

Heat Treated ◽

Columnar Grains ◽

Different Temperatures ◽

Plasma Sprayed ◽

Equiaxed Grains ◽

Sprayed Coatings ◽

Lamellar Interfaces

Pure nickel powder was low pressure plasma sprayed onto a steel substrate held at different temperatures during spraying. The as-sprayed coatings consist of columnar grains whose axes are nearly perpendicular to the lamellae composing the coatings. As the coating temperature becomes higher, the length of the columnar grains increases and is longer than the thickness of the lamellae, indicating the growth of the grains across the lamellar interfaces during spraying. On the other hand, the coatings that were heat treated after spraying consist of coarse equiaxed grains. The coatings that experienced high temperatures during spraying or the heat treated coatings have large porosity and contain large globular pores. The hardness, apparent density and the tensile strength of the coating itself were the highest for the coating prepared at a low temperature and became low on heat treatment. The thermal conductivity in the direction perpendicular to the coating was the largest for the coating that consisted of long columnar grains.

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Comparison of Physical-chemical and Mechanical Properties of Chlorapatite and Hydroxyapatite Plasma Sprayed Coatings

The Open Biomedical Engineering Journal ◽

10.2174/1874120701509010042 ◽

2015 ◽

Vol 9 (1) ◽

pp. 42-55 ◽

Cited By ~ 8

Author(s):

Imane Demnati ◽

David Grossin ◽

Olivier Marsan ◽

Ghislaine Bertrand ◽

Gérard Collonges ◽

...

Keyword(s):

Side Reaction ◽

Processing Parameters ◽

X Ray Diffraction ◽

Unexpected Formation ◽

Monoclinic Form ◽

Ion Exchange Reaction ◽

Physical Chemical ◽

Distribution Mapping ◽

Sprayed Coating ◽

Plasma Sprayed

Chlorapatite can be considered a potential biomaterial for orthopaedic applications. Its use as plasma-sprayed coating could be of interest considering its thermal properties and particularly its ability to melt without decomposition unlike hydroxyapatite. Chlorapatite (ClA) was synthesized by a high-temperature ion exchange reaction starting from commercial stoichiometric hydroxyapatites (HA). The ClA powder showed similar characteristics as the original industrial HA powder, and was obtained in the monoclinic form. The HA and ClA powders were plasma-sprayed using a low-energy plasma spraying system with identical processing parameters. The coatings were characterized by physical-chemical methods, i.e. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy, including distribution mapping of the main phases detected such as amorphous calcium phosphate (ACP), oxyapatite (OA), and HA or ClA. The unexpected formation of oxyapatite in ClA coatings was assigned to a side reaction with contaminating oxygenated species (O2, H2O). ClA coatings exhibited characteristics different from HA, showing a lower content of oxyapatite and amorphous phase. Although their adhesion strength was found to be lower than that of HA coatings, their application could be an interesting alternative, offering, in particular, a larger range of spraying conditions without formation of massive impurities.

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Transient Phenomena in Plasma Torches and in Plasma Sprayed Coating Generation

Journal de Physique IV (Proceedings) ◽

10.1051/jp4:1997414 ◽

1997 ◽

Vol 07 (C4) ◽

pp. C4-187-C4-198 ◽

Cited By ~ 10

Author(s):

P. Fauchais ◽

J. F. Coudert ◽

M. Vardelle

Keyword(s):

Transient Phenomena ◽

Plasma Torches ◽

Sprayed Coating ◽

Plasma Sprayed

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Surface integrity design of plasma sprayed coating for resisting contact fatigue

Materials Chemistry and Physics ◽

10.1016/j.matchemphys.2016.05.025 ◽

2016 ◽

Vol 179 ◽

pp. 174-181 ◽

Cited By ~ 7

Author(s):

Piao Zhong-yu ◽

Xu Jia ◽

Yin Lin-zhi ◽

Wen Dong-hui ◽

Xu Bin-shi ◽

...

Keyword(s):

Surface Integrity ◽

Contact Fatigue ◽

Sprayed Coating ◽

Plasma Sprayed

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Mechanofusion Processing of Metal-Oxide Composite Powders for Plasma Spraying

MRS Proceedings ◽

10.1557/proc-1276-25 ◽

2010 ◽

Vol 1276 ◽

Author(s):

Ricardo Cuenca-Alvarez ◽

Carmen Monterrubio-Badillo ◽

Hélêne Ageorges ◽

Pierre Fauchais

Keyword(s):

Mechanical Energy ◽

Xrd Analysis ◽

Composite Particles ◽

Composite Powders ◽

Steel Core ◽

No Formation ◽

Particle Coating ◽

Plasma Sprayed Coatings ◽

Plasma Sprayed ◽

Sprayed Coatings

AbstractComposite particles destined to build plasma sprayed coatings, are prepared by the mechanofusion process (MF). These particles consist of a stainless steel core particle coated by finer particles of alumina. Changes induced by the MF process are monitored by SEM, DRX, and laser granulometry, revealing that the dry particle coating process is governed by agglomeration and rolling phenomena. Simultaneously, the MF performance is controlled by the operating parameters such as the compression gap, the mass ratio of host to guest particle, and the powder input rate. The mechanical energy input leads to a nearly rounded shape of the final composite particles; however, no formation of new phases or components decomposition is detected by XRD analysis. The resulting composite powder features optimal characteristics, concerning particle shape and phases distribution, to be plasma sprayed in air.

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