Microstructural Study of Nanostructured ZrO2 Based Thermal Barrier Coatings Fabricated by High Efficiency Supersonic Plasma Spraying

In this paper, the microstructure of nanostructured zirconia (ZrO2) based coating fabricated by newly developed process, high efficiency supersonic atmospheric plasma spraying (SAPS), is studied. The velocity and surface temperature of in-flight particles during spraying were monitored by on-line system and the microstructure and phase composition of the as-sprayed coating was characterized with SEM, TEM and XRD. Meanwhile, the bonding strength between the top coating and bond coating was measured. The results showed the average in-flight velocity of YSZ particles in SAPS was about 430m/s, which was much higher than that of conventional atmospheric plasma spraying (APS). The as-sprayed coating was composed of well-adhered fine lamellar structures with thickness of 1-4μm. The desirable structure was attributed to higher impact velocity of in-flight particles during SAPS process, resulting in the improvement of flattening degree of molten particles. Meanwhile, the SAPS-YSZ coating exhibited a bimodal distribution with small grains (30-50nm) and large grains (60-110nm), the latter was the main microstructure of the coating. In addition, it was found that the monoclinic zirconia existing in the original powders transformed into tetragonal phase after plasma spraying and the bonding strength of as-sprayed coating was as high as 46±3MPa. The high efficiency supersonic plasma spray, which offers some unique advantages over the conventional plasma spraying process, is expected to be potentially used to deposit a wide variety of nanostructured coatings at lower cost.

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Comparison of Dry Sliding Tribological Behavior of Nanostructured Al2O3–13 wt% TiO2 Coatings Prepared by High-Efficiency Supersonic Plasma Spraying and Atmospheric Plasma Spraying

Journal of Tribology ◽

10.1115/1.4048886 ◽

2020 ◽

Vol 143 (7) ◽

Author(s):

Zi-ang Jin ◽

Jian-long Ma ◽

Li-na Zhu ◽

Hai-dou Wang ◽

Guo-lu Li ◽

...

Keyword(s):

Plasma Spraying ◽

Friction And Wear ◽

High Efficiency ◽

Atmospheric Plasma Spraying ◽

Atmospheric Plasma ◽

Wear Volume ◽

Dry Sliding ◽

Wear Protection ◽

Supersonic Plasma ◽

Tio2 Coatings

Abstract Plasma-sprayed ceramic coatings have been widely used in friction and wear protection of mechanical parts. In this paper, the nanostructured Al2O3–13 wt% TiO2 coatings were prepared by high-efficiency supersonic plasma spraying (HESP) and atmospheric plasma spraying (APS), respectively. The surface and section morphology of the coatings were observed by scanning electron microscopy (SEM). The phase composition of the coatings was analyzed by X-ray diffraction (XRD). The dry sliding friction properties of the coatings were tested on UMT-3 friction and wear testing machine. The results show that after plasma spraying, a large amount of γ-Al2O3 phase appears, while the TiO2 phase almost disappears in the coatings; compared with APS, the coatings sprayed by HESP have fewer defects and better coating quality; under dry friction condition, the steady-state friction coefficient of the coatings sprayed by HESP and APS all decreases with the increase of load, and the wear volume all increases with the increase of load. When the load is more than 40 N, wear volume of the coatings sprayed by APS is basically twice that of HESP; the wear mechanism of the coatings sprayed by HESP is the laminar cracking, peeling off and the adhesive wear.

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Influences of Metal Sprayed Coating Artificial Dental Root on the Vital Tissue

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

10.31399/asm.cp.itsc1998p1079 ◽

1998 ◽

Author(s):

M. Magome ◽

K. Hara ◽

K. Sano ◽

Y. Ueda

Keyword(s):

Plasma Spraying ◽

Atmospheric Plasma Spraying ◽

Aluminum Coating ◽

The Other ◽

Atmospheric Plasma ◽

In Vitro Experiments ◽

Wire Frame ◽

Sprayed Coating

Abstract Artificial dental root material has been very important among all bio-materials. In this study, two different ways of aluminum coating are used. One is wire frame spraying, and the other is atmospheric plasma spraying. The affinity, stability, and connectivity of aluminum toxins with sprayed coating are used and the possibility for applying ways are examined. Acute toxic tests are performed clinically. Both in-vivo and in-vitro experiments are performed on a dog, and the results showed that aluminum sprayed coating is good as an artificial dental root material.

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Ablation Behavior of HfC Coating Prepared by Supersonic Plasma Spraying for SiC-Coated C/C Composites

Advanced Composites Letters ◽

10.1177/096369351502400503 ◽

2015 ◽

Vol 24 (5) ◽

pp. 096369351502400 ◽

Cited By ~ 8

Author(s):

Yang Yang ◽

Kezhi Li ◽

Hejun Li

Keyword(s):

Plasma Spraying ◽

Atmospheric Plasma Spraying ◽

Atmospheric Plasma ◽

X Ray Diffraction ◽

Dense Structure ◽

X Ray ◽

Ablation Resistance ◽

Supersonic Plasma ◽

Centre Region ◽

Supersonic Atmospheric Plasma Spraying

In order to improve the ablation resistance of C/C composites HfC coating was deposited on the surface of SiC-coated C/C composites by supersonic atmospheric plasma spraying. The microstructure and morphology of the different coatings were characterized by Scanning Electron Microscopy, X-ray diffraction. The ablation test of samples was carried out with an oxyacetylene torch. The coating exhibits dense structure and good ablation resistance. After ablation for 30s, the linear and mass ablation rates of the coating are 0.59 μm/s and 0.6 mg/s, respectively. In ablation centre region, a HfO2 layer is formed on the surface of sample after 30s ablation, and it can protect C/C composites from ablation.

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