Preparation and Investigation of High Emissivity Coatings Prepared by Plasma Spraying

2012 ◽  
Vol 512-515 ◽  
pp. 1062-1065 ◽  
Author(s):  
Can Wang ◽  
Quan Sheng Wang ◽  
Xian Kai Sun
Keyword(s):  
Bond Strength ◽  
Plasma Spraying ◽  
Raw Materials ◽  
Air Plasma ◽  
Before And After ◽  
Plasma Sprayed ◽  
Plasma Spraying Process ◽  
Normal Emissivity ◽  
Spraying Process ◽  
High Emissivity

The high emissivity coating was deposited by Air Plasma Spraying (APS). Ni2O3, Cr2O3 were the main raw materials in this study. The feedstock powder was prepared by spray drying and post-sintering at 1420 °C for 2hours. The microstructure, phase structure, flowability and bulk density of the plasma sprayed powder were characterized. The microstructure, bond strength and infrared emissivity of the high emissivity coating were also analyzed in this paper. The results reveal that the powder before and after sintering presents good flowability and is suitable for plasma spraying process. A dense coating with the bond strength of 28.14MPa was prepared successfully. The normal emissivity of the coating in all waveband is 0.87 at the temperature of 300°C, 600°C, 900°C, 1000°C, 1100°C and 1200°C

Investigation of High Emissivity Coatings Prepared by Plasma Spraying

2011 ◽  
Vol 287-290 ◽  
pp. 2283-2287
Author(s):  
Can Wang ◽  
Quan Sheng Wang ◽  
Xian Jin Ning ◽  
Zhong Du ◽  
Yan Bo Liu ◽  
...  
Keyword(s):  
Bond Strength ◽  
Bulk Density ◽  
Plasma Spraying ◽  
Infrared Emissivity ◽  
Air Plasma ◽  
Air Plasma Spraying ◽  
Feedstock Powder ◽  
Plasma Sprayed ◽  
Normal Emissivity ◽  
High Emissivity

In this study, the feedstock powder for plasma spray was prepared by spray drying and post-sintering at 1360 °C using raw metal oxides. The high emissivity coating was deposited by air plasma spraying (APS). The microstructure, phase structure, flowability and bulk density of the plasma sprayed powder were characterized. The microstructure, bond strength and infrared emissivity of the high emissivity coating were also analyzed in this paper. The results reveal that the feedstock powder present good flowability of 42.36 (sp50g) with the bulk density of 1.94 gpml and is suitable for plasma spraying. A dense coating with the bond strength of 39.6MPa and the porosity less than 5 percent was prepared successfully. The normal emissivity of the coating in all waveband is 0.88 at 300°C and 0.87 at 600°C.

Comparative Study on Nano-Structural and Traditional Al2O3-13TiO2 Air Plasma Sprayed Coatings and their Thermal Shock Performance

2017 ◽  
Vol 739 ◽  
pp. 103-107 ◽  
Author(s):  
Sun Hui Yao ◽  
Yan Liang Su ◽  
Hung Yu Shu ◽  
Chia I Lee ◽  
Zong Ling You
Keyword(s):  
Comparative Study ◽  
Thermal Shock ◽  
Raw Materials ◽  
Thermal Shock Test ◽  
Air Plasma ◽  
Cyclic Heat Treatment ◽  
Shock Test ◽  
Before And After ◽  
Nanostructural Coating ◽  
Plasma Sprayed

This paper reports a comparative study on characterization and thermal shock behavior of air plasma sprayed Al2O3-13wt.%TiO2 coatings using two kinds of raw materials, i.e. nanostructural and micro-structural (traditional) feedstock powders. The characterization, before and after thermal shock test, was carried out using micro-Vickers hardness tester, XRD and SEM. The thermal shock test was carried out using a water quenching method by employing cyclic heat treatment between ambient temperature and 650°C in air. The results showed that in spite of having denser structure, the nanostructural coating showed hardness a little lower than the traditional one at both conditions of before and after thermal shock tests. However, the nanostructural coating showed very good thermal shock behaviour.

Microstructure of Al2O3-13TiO2 Coatings Deposited from Nanoparticles by Plasma Spraying

2013 ◽  
Vol 58 (2) ◽  
pp. 335-339 ◽  
Author(s):  
A. Góral ◽  
L. Litynska-Dobrzynska ◽  
W. Zórawski ◽  
K. Berent ◽  
J. Wojewoda-Budka
Keyword(s):  
Plasma Spraying ◽  
Steel Substrate ◽  
Nanosized Particles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lamellar Morphology ◽  
Transmission Electron ◽  
Plasma Sprayed ◽  
Plasma Spraying Process ◽  
Spraying Process

The aim of the study was to characterize nanostructured Al2O3-13TiO2 coatings deposited by plasma spraying on a grit blasted steel substrate. The Al2O3-13TiO2 coatings were characterized using scanning and transmission electron microscopy and X-ray diffraction techniques. Obtained coatings possessed a unique microstructure consisting of fully melted regions with the microstructure similar to a typical plasma sprayed lamellar morphology as the conventional coatings and areas comprising unmelted or partially melted nanosized particles. The analysis showed that most of the α-Al2O3 phase from the nanostructured powders transformed into γ-Al2O3 phase after plasma spraying process. Moreover, the presence of amorphous phase was also observed.

Deposition of Fe-based metallic glass coatings by Air Plasma Spraying process

2010 ◽  
Vol 4 (3) ◽  
pp. 288 ◽  
Author(s):  
Fuping Li ◽  
Jinshan Li ◽  
Hongchao Kou ◽  
Chaoping Jiang ◽  
Xiangyi Xue ◽  
...  
Keyword(s):  
Metallic Glass ◽  
Plasma Spraying ◽  
Air Plasma ◽  
Air Plasma Spraying ◽  
Plasma Spraying Process ◽  
Spraying Process

Microstructure and Property of Plasma Sprayed TiB2 Wettable Coatings on Carbon Cathodes

2014 ◽  
Vol 881-883 ◽  
pp. 1580-1583 ◽  
Author(s):  
Ru Zhen Peng ◽  
Gang Xie ◽  
Yan Qing Hou ◽  
Lin Tian ◽  
Xiao Hua Yu
Keyword(s):  
Plasma Spraying ◽  
High Performance ◽  
Good Choice ◽  
Carbon Substrate ◽  
Oxide Reduction ◽  
Fine Powders ◽  
Cathode Carbon ◽  
Plasma Sprayed ◽  
Plasma Spraying Process ◽  
Spraying Process

In this work, fine-lamellar structured TiB2 ceramic wettable cathode coatings were deposited on carbon cathodes of aluminium oxide reduction cells by atmosphere plasma spraying (APS). Cathode carbon blocks consisting of coatings 800 μm thick of plasma sprayed TiB2 finepowder on carbon substrate were fabricated. In order to investigate the results of coating, the microstructure and phase composition of the wettable cathode coating were characterized by scanning electron microscopy (SEM). It is found that TiB2 fine-powders were partly oxidized during the plasma spraying process. The coating was mostly formed by a matrix of fully molten particles where the presence of semi-molten feedstock agglomerates. The APS method is believed to be a good choice to deposit TiB2 wettable cathode coating with high performance and reliability.

Electron microscopy studies of plasma-sprayed materials

1983 ◽  
Vol 41 ◽  
pp. 70-71
Author(s):  
K.R. Subramanian ◽  
A.H. King ◽  
H. Herman
Keyword(s):  
Plasma Spraying ◽  
Substrate Surface ◽  
Flame Temperature ◽  
Ceramic Coatings ◽  
Metallic Substrates ◽  
Hot Plasma ◽  
Almost All ◽  
Plasma Sprayed ◽  
Hostile Environments ◽  
Plasma Spraying Process

Plasma spraying is a technique which is used to apply coatings to metallic substrates for a variety of purposes, including hardfacing, corrosion resistance and thermal barrier applications. Almost all of the applications of this somewhat esoteric fabrication technique involve materials in hostile environments and the integrity of the coatings is of paramount importance: the effects of process variables on such properties as adhesive strength, cohesive strength and hardness of the substrate/coating system, however, are poorly understood.Briefly, the plasma spraying process involves forming a hot plasma jet with a maximum flame temperature of approximately 20,000K and a gas velocity of about 40m/s. Into this jet the coating material is injected, in powder form, so it is heated and projected at the substrate surface. Relatively thick metallic or ceramic coatings may be speedily built up using this technique.

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