scholarly journals Microstructural Charactistics of Plasma Sprayed NiCrBSi Coatings and Their Wear and Corrosion Behaviors

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 170
Author(s):  
Songqiang Huang ◽  
Jingzhong Zhou ◽  
Kuoteng Sun ◽  
Hailiang Yang ◽  
Weichen Cai ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Acid Corrosion ◽  
Composite Coatings ◽  
Atmospheric Plasma ◽  
Confocal Laser ◽  
Formation Mechanisms ◽  
Temperature Oxidation ◽  
Surface Protection ◽  
Plasma Sprayed ◽  
Nicrbsi Coatings

Nickel-based alloys are commonly used as protective coating materials for surface protection applications owing to their superior resistance to corrosion, wear and high-temperature oxidation. It is urgent to study the fundamental mechanism between the structure and corrosion properties of the Nickel-base composite coatings. This paper, therefore, focuses on clarifying the mechanisms of the microstructure influencing the acid corrosion and mechanical characteristics of the as-sprayed NiCrBSi coating and post-heat-treated coating. The formation mechanisms of the amorphous phase of flat particles during the plasma spray process were studied by using X-ray diffraction analysis, Raman spectroscopy and confocal laser scanning microscope at first. Then the evolutionary process of the corrosion structure and phase of the coating in the accelerated corrosion experiment is directly visualized by using scanning electron microscopy and energy spectrum analysis. The mechanical properties of the amorphous NiCrBSi coatings are lastly measured by microhardness and friction wear tests. The critical phenomena and results help to elucidate the relative influence of the surface features of atmospheric plasma sprayed coatings on acid corrosion responses and wear resistance, aiming at contributing to the development of a protective technique for electrical engineering.

Fabrication and Ablation Behavior of Plasma Sprayed ZrC-W Composite Coatings

2014 ◽  
Vol 602-603 ◽  
pp. 552-555
Author(s):  
Dan Lu ◽  
Ya Ran Niu ◽  
Xue Lian Ge ◽  
Xue Bing Zheng ◽  
Guang Chen
Keyword(s):  
Thermal Conductivity ◽  
Thermal Shock ◽  
Plasma Spray ◽  
Composite Coatings ◽  
Lamellar Microstructure ◽  
Atmospheric Plasma Spray ◽  
Atmospheric Plasma ◽  
Plasma Flame ◽  
Plasma Sprayed ◽  
Zrc Coating

In this work, atmospheric plasma spray (APS) technology was applied to fabricate ZrC-W composite coatings. The microstructure of the composite coatings was characterized. The influence of W content on the ablation-resistant and thermal shock properties of ZrC-W composite coatings was evaluated using a plasma flame. The results show that the ZrC-W composite coatings had typically lamellar microstructure, which was mainly made up of cubic ZrC, cubic W and a small amount of tetragonal ZrO2. The ZrC-W coatings had improved ablation resistant and thermal shock properties compared with those of the pure ZrC coating. It was supposed that the improved density, thermal conductivity and toughness of the composite coatings contributed to this phenomenon.

scholarly journals Particle Size-Dependent Microstructure, Hardness and Electrochemical Corrosion Behavior of Atmospheric Plasma Sprayed NiCrBSi Coatings

Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1342 ◽  
Author(s):  
Peng Sang ◽  
Liang-Yu Chen ◽  
Cuihua Zhao ◽  
Ze-Xin Wang ◽  
Haiyang Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Corrosion Behavior ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Charge Transfer Resistance ◽  
Atmospheric Plasma ◽  
Transfer Resistance ◽  
Electrochemical Corrosion Behavior ◽  
Plasma Sprayed ◽  
Nicrbsi Coatings

Particle size is a critical consideration for many powder coating-related industries since it significantly influences the properties of the produced materials. However, the effect of particle size on the characteristics of plasma sprayed NiCrBSi coatings is not well understood. This work investigates the microstructures, hardness and electrochemical corrosion behavior of plasma sprayed NiCrBSi coatings synthesized using different-sized powders. All coatings mainly consist of Ni, N3B, CrB, Cr7C3 and Cr3C2 phases. The coatings produced by small particles (50–75 μm) exhibit lower porosity (2.0 ± 0.8%). Such coatings show a higher fraction (15.5 vol.%) of the amorphous phase and lower hardness (700 HV0.5) than the counterparts (8.7 vol.% and 760 HV0.5, respectively) produced by large particles (75–100 μm) with higher porosity (3.0 ± 1.6%). Meanwhile, the coatings produced from smaller particles possess a larger number of non-bonded boundaries, leading to the easier penetration of corrosive medium, as well as a higher corrosion current density (0.254 ± 0.062 μA/cm2) and a lower charge transfer resistance (0.37 ± 0.07 MΩ cm2). These distinctions are attributed to particle size-induced different melting degrees and stackings of in-flight particles during deposition.

scholarly journals Porosity and Its Significance in Plasma-Sprayed Coatings

Coatings ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 460 ◽  
Author(s):  
John Gerald Odhiambo ◽  
WenGe Li ◽  
YuanTao Zhao ◽  
ChengLong Li
Keyword(s):  
Working Environment ◽  
Atmospheric Plasma ◽  
Formation Mechanisms ◽  
Multilayer Coatings ◽  
Oxide Coatings ◽  
Spraying Parameters ◽  
Plasma Sprayed Coatings ◽  
Sprayed Coating ◽  
Plasma Sprayed ◽  
Sprayed Coatings

Porosity in plasma-sprayed coatings is vital for most engineering applications. Porosity has its merits and demerits depending on the functionality of the coating and the immediate working environment. Consequently, the formation mechanisms and development of porosity have been extensively explored to find out modes of controlling porosity in plasma-sprayed coatings. In this work, a comprehensive review of porosity on plasma-sprayed coatings is established. The formation and development of porosity on plasma-sprayed coatings are governed by set spraying parameters. Optimized set spraying parameters have been used to achieve the most favorable coatings with minimum defects. Even with the optimized set spraying parameters, defects like porosity still occur. Here, we discuss other ways that can be used to control porosity in plasma-sprayed coating with emphasis to atmospheric plasma-sprayed chromium oxide coatings. Techniques like multilayer coatings, nanostructured coatings, doping with rare earth elements, laser surface re-melting and a combination of the above methods have been suggested in adjusting porosity. The influences of porosity on microstructure, properties of plasma-sprayed coatings and the measurement methods of porosity have also been reviewed.

Relationships between Microstructural and Mechanical Properties of Plasma Sprayed AlSi-Polyester Composite Coatings: Application to Abradable Materials

2014 ◽  
Vol 606 ◽  
pp. 155-158 ◽  
Author(s):  
Yann Duramou ◽  
Rodolphe Bolot ◽  
Jean Louis Seichepine ◽  
Yoann Danlos ◽  
Pierre Bertrand ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Composite Coatings ◽  
Tip Clearance ◽  
Atmospheric Plasma ◽  
Inner Surface ◽  
Polyester Composite ◽  
Overall Efficiency ◽  
Plasma Sprayed ◽  
Abradable Coatings ◽  
Thermal Spray Processes

Abradable coatings are widely used within aeroengines. These materials are applied onto the inner surface of compressor and turbine shroud sections using thermal spray processes, coating the periphery of the blade rotation path. The functionality of an abradable seal is to wear preferentially when rotating blades come into contact with it, while minimizing the over-tip clearance, and improving the overall efficiency of the engine. This study is concerned with the relationships between the microstructure and mechanical properties of atmospheric plasma sprayed AlSi-Polyester composite coatings.

scholarly journals Effect of Arc Power on the Wear and High-temperature Oxidation Resistances of Plasma-Sprayed Fe-based Amorphous Coatings

2019 ◽  
Vol 38 (2019) ◽  
pp. 639-646
Author(s):  
Jinheng Luo ◽  
Na Shi ◽  
Ya-Zhe Xing ◽  
Chaoping Jiang ◽  
Yongnan Chen
Keyword(s):  
High Temperature ◽  
Amorphous Phase ◽  
High Temperature Oxidation ◽  
Steel Substrate ◽  
Atmospheric Plasma ◽  
X Ray Diffraction ◽  
Temperature Oxidation ◽  
Arc Power ◽  
Plasma Sprayed ◽  
Amorphous Coatings

AbstractAtmospheric plasma spraying (APS) technique is employed to prepare Fe-based amorphous coatings on T91 steel substrate under various arc powers of 30 kW, 35 kW and 40kW. The morphology and microstructure of both Fe-based powders and amorphous coatings are characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). In addition, the wear resistance and high-temperature oxidation resistance of the plasma-sprayed coatings at various arc powers are studied. It is found that with increasing the arc power, the content of the porosity and the amorphous phase in the coatings declines. Specifically, under 30 kW, 35 kW and 40 kW arc power, the porosity of the coatings is 7.96%, 6.13% and 5.75%. Correspondingly, the relative content of amorphous phase from the coatings is measured to be 96.07% (mass fraction), 73.89% and 65.54%. Moreover, under 40 kW arc power, it gives the coating the highest micro-hardness having more compact microstructure and more dispersive α-Fe grains. Besides, the coatings fabricated at high arc power exhibit less wear induced weight loss and less weight gain from high-temperature oxidation comparing with those fabricated at lower arc power.

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