Development of Al-Alloy Coating for Advanced Nuclear Systems Using Lead Alloys

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Yuji Kurata ◽  
Hitoshi Yokota ◽  
Tetsuya Suzuki
Keyword(s):  
Corrosion Resistance ◽  
Laser Beam ◽  
Coating Layer ◽  
Alloy Coating ◽  
Al Alloy ◽  
Corrosion Attack ◽  
Lead Alloys ◽  
Nuclear Systems ◽  
Coating Layers ◽  
Al Powder

Small and medium reactors using lead alloys as coolants are one of the promising reactor concepts with improved safety because of their thermal-physical and chemical properties. This paper focuses on the development of Al-alloy coating for nuclear systems using liquid lead-bismuth eutectic (LBE). Since corrosion attack becomes severe against structural steels at high temperatures in liquid LBE, it is necessary to improve the corrosion resistance of steels. An Al-alloy coating method using Al, Ti, and Fe powders, and laser beam heating has been developed. The main defects formed in the Al-powder-alloy coating process are surface defects and cracks. The conditions required to avoid these defects are the employment of the laser beam scanning rate of 20 mm/min and the adjustment of the Al concentration in the coating layer. According to the results of the corrosion tests at 550 °C in liquid LBE, the Al-alloy coating layers on 316SS prevent severe corrosion attack such as grain boundary corrosion and LBE penetration observed in the 316SS without coating. The good corrosion resistance of the Al-alloy coating is based on the thin Al-oxide film, which can be regenerated in liquid LBE. From the viewpoint of the soundness of the produced Al-powder-alloy coating layers and the preservation of their corrosion resistance, it is estimated that the range of adequate Al concentration in the coating layer is from 4 to 12 wt. %.

Development of Aluminum Alloy Coating for Advanced Nuclear Systems Using Lead Alloys

2011 ◽  
Author(s):  
Yuji Kurata ◽  
Hitoshi Yokota ◽  
Tetsuya Suzuki
Keyword(s):  
Corrosion Resistance ◽  
Laser Beam ◽  
Coating Layer ◽  
Alloy Coating ◽  
Al Alloy ◽  
Corrosion Attack ◽  
Lead Alloys ◽  
Nuclear Systems ◽  
Coating Layers ◽  
Al Powder

Small and medium reactors using lead alloys as coolant are one of the promising reactor concepts with improved safety because of their thermal-physical and chemical properties. This paper focuses on development of Al-alloy coating for nuclear systems using liquid lead-bismuth eutectic (LBE). Since corrosion attack becomes severe against structural steels at high temperatures in liquid LBE, it is necessary to improve corrosion resistance of steels. An Al-alloy coating method using Al, Ti and Fe powders, and laser beam heating has been developed. Main defects formed in an Al-powder-alloy coating process are surface defects and cracks. Conditions required to avoid these defects are employment of the laser beam scanning rate of 20 mm/min and adjustment of the Al concentration in the coating layer. According to results of the corrosion tests at 550°C in liquid LBE, the Al-alloy coating layers on 316SS protect severe corrosion attack such as grain boundary corrosion and LBE penetration observed in 316SS without coating. The good corrosion resistance of the Al-alloy coating is based on the thin Al-oxide film which can be regenerated in liquid LBE. From the viewpoints of the soundness of produced Al-powder-alloy coating layers and preservation of their corrosion resistance, it is estimated that the range of the adequate Al concentration in the coating layer is from 4 to 12 wt%.

scholarly journals Microstructural characterization of accident tolerant fuel cladding with Cr–Al alloy coating layer after oxidation at 1200 °C in a steam environment

2020 ◽  
Vol 52 (10) ◽  
pp. 2299-2305 ◽  
Author(s):  
Dong Jun Park ◽  
Yang Il Jung ◽  
Jung Hwan Park ◽  
Young Ho Lee ◽  
Byoung Kwon Choi ◽  
...  
Keyword(s):  
Coating Layer ◽  
Microstructural Characterization ◽  
Alloy Coating ◽  
Al Alloy ◽  
Fuel Cladding

Effect of Alkaline Phosphate-Permanganate Conversion Coating on the Corrosion Resistance of AZ91D Magnesium Alloy

2014 ◽  
Vol 974 ◽  
pp. 43-49 ◽  
Author(s):  
Young Min Byoun ◽  
Jin Hwan Jeong ◽  
Jong Kyu Park ◽  
Sun Kyo Seo ◽  
Chi Hwan Lee
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Coating Layer ◽  
Salt Spray ◽  
Xrd Analysis ◽  
Conversion Coating ◽  
Surface And Interface ◽  
Az91d Magnesium Alloy ◽  
Coating Layers ◽  
Alkaline Phosphate

Alkaline phosphate-permanganate conversion coating, chrome-free conversion coating was studied for corrosion resistance of AZ91D magnesium alloy. Also, conventional acid phosphate -permanganate conversion coating was studied for comparison. Analysis and morphology observation for conversion coating layers was investigated in details by using SEM-EDS, XRD. SEM observation showed that a lot of cracks in surface and interface between conversion coating layer and AZ91D magnesium alloy substrate was observed in acid conversion coating, whereas cracks was not almost observed in alkaline conversion coating layer. SEM-EDS and XRD analysis showed that the main elements of both alkaline and acid conversion coating were Mg, O, K, P and Mn. It was found that both conversion coating layers was consisted of MgO, Mg (OH)2and MnO2. Salt spray test showed that the alkaline conversion coating have a good corrosion resistance compared with acid conversion coating.

Influence of Rare Earth on Hot-Dipped 55%Al-Zn Alloy Coating

2013 ◽  
Vol 774-776 ◽  
pp. 1132-1136 ◽  
Author(s):  
Tai Xiong Guo ◽  
Xue Qiang Dong ◽  
Shu Hui Deng ◽  
Feng Li ◽  
Yi Lin Zhou
Keyword(s):  
Corrosion Resistance ◽  
Rare Earth ◽  
Simulation Experiment ◽  
Steel Substrate ◽  
Intermetallic Layer ◽  
Alloy Coating ◽  
Al Alloy ◽  
Zinc Dross ◽  
Zn Alloy ◽  
The Rare Earth

Simulation experiment was done to investigate the effects of rare earth on hot-dipped Zn-55%Al alloy coating. The results show that the rare earth has little effect on the zinc dross and its burning loss is about 10%. The microstructure of coating is similar to that of solidification bath, and which is made up of phases of rich aluminum, rich zinc, rich silicon and rare earth, and intermetallic layer of Al-Zn-Fe-Si. The rare earth phase is needle or rod, and mainly distributed inside rich zinc phase and on the interface between the coating and steel substrate. The rare earth has no obvious influence on coating grain and spangle size. The appropriate addition of rare earth would be helpful to improve the coating bending formability and corrosion resistance.

scholarly journals Minor Special Issue on Corrosion. Evaluation of Corrosion Resistance for Zn-5%Al Alloy Coating on Steel Structures.

1993 ◽  
Vol 42 (479) ◽  
pp. 941-947
Author(s):  
Yoshihiko TAKANO ◽  
Tatsumi IZEKI ◽  
Tetsuya NAKADA ◽  
Koshi TAKADA ◽  
Masamichi YAMASHITA
Keyword(s):  
Corrosion Resistance ◽  
Steel Structures ◽  
Alloy Coating ◽  
Al Alloy ◽  
Special Issue ◽  
Corrosion Evaluation

scholarly journals Influence of Microstructure on Corrosion Resistance in Zn-Al Alloy Coating

1986 ◽  
Vol 72 (8) ◽  
pp. 1005-1012 ◽  
Author(s):  
Tetsuya KIYASU ◽  
Akira YASUDA ◽  
Shigeru KOBAYASHI ◽  
Toshio ICHIDA ◽  
Hiroshi KUBO
Keyword(s):  
Corrosion Resistance ◽  
Alloy Coating ◽  
Al Alloy

Study on Corrosion-Resisting Properties of High-Speed Arc Sprayed Zn-Al Alloy Coating in Caverns

2011 ◽  
Vol 399-401 ◽  
pp. 2072-2078
Author(s):  
Miao Lou ◽  
Yu Feng Lu ◽  
Chun Lin Ma ◽  
Yong Le Hu ◽  
Meng Zhou ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
High Speed ◽  
Salt Spray ◽  
Alloy Coating ◽  
Arc Spraying ◽  
Al Alloy ◽  
Test Study ◽  
High Velocity Arc Spraying ◽  
Steel Substrates ◽  
Al Coating

Zn、Al alloy coatings were prepared by high velocity arc spraying technology on 16MnR steel substrates, With the design salt spray test, Study on the corrosion resistance of the Zn、Al alloy coating in the grotto environment. The porosity of the metal coating and the compact of the corrosion are infection on the corrosion resistance of the coating. Al coating and Zn/Al(300/100) coating corrosion resistance better than others on 16MnR steel.

Low-pressure cold metal spray coatings for repair and protection of marine components

2018 ◽  
Author(s):  
M Pal
Keyword(s):  
Marine Environment ◽  
Alloy Coating ◽  
Al Alloy ◽  
Metallic Coatings ◽  
Material State ◽  
Paint Coatings ◽  
And Performance ◽  
Cuzn Alloy ◽  
Cold Metal ◽  
Metal Spray

The marine environment is hostile to most engineering materials, a combination of in-service wear and exposure to marine environment leads to an accelerated material degradation.  Insufficient or poor protection of the substrates further assists the accelerated material degradation in marine environment. There is a direct relationship between the material-state of a ship and its operational capability, readiness, and service life.  The current state-of-the-art practice is to use paint-based coatings to maintain the material-state of ships.  However, the protection offered by paint coatings is usually brief due to inherent permeability and low damage tolerance of these coatings.  For this reason, the paint coatings require renewal at regular intervals, typically less than 5-years, to maintain a minimum level of protection from the marine environment.  The need for regular painting of ships results in a significant negative impact on the through-life availability, operational capability/readiness, and the cost of maintenance/operation of naval ships.  Therefore, the fleet owners and operators should look beyond the conventional paint-based coatings to achieve significant breakthrough improvements in maintaining and enhancing the material-state of naval ships. Metallic coatings, if selected and applied appropriately, will outperform the paint coatings in the marine environment.  Historically, the cost and performance of metallic coatings, mainly thermal metal spray (TMS) coatings, prevented their widespread use in the marine industry.  The TMS coatings also have their own inherent application and performance related limitations that are widely reported in the literature.  However, the cold metal spray (CMS) coating process can overcome the application and performance related limitations that are typically associated with the TMS coatings, therefore creating an opportunity for widespread use of metallic coatings in shipbuilding and fleet upkeep/maintenance. In this paper, the ability of low-pressure (LP-CMS) coatings to repair and reclaim damaged marine components, and application of functional coatings to improve in-service damage tolerance of the damaged/new components is investigated.  The results of the investigation show that two LP-CMS coatings, Al-alloy and CuZn-alloy, can be used to repair and preserve both new and damaged components.  The accelerated salt-spray and natural immersion corrosion testing of the LP-CMS coatings showed that each coating will be better suited to a particular operational environment, i.e. CuZn-alloy coating performed well in both immersion and atmospheric corrosion environments, whereas Al-alloy coating performed well only in atmospheric corrosion environment. 

scholarly journals Surface Modification of Aluminum 6061-O Alloy by Plasma Electrolytic Oxidation to Improve Corrosion Resistance Properties

Coatings ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 4
Author(s):  
Dmitry V. Dzhurinskiy ◽  
Stanislav S. Dautov ◽  
Petr G. Shornikov ◽  
Iskander Sh. Akhatov
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Plasma Electrolytic Oxidation ◽  
Electrochemical Impedance ◽  
High Strength ◽  
Electrolytic Oxidation ◽  
Coating Layers ◽  
Plasma Electrolytic ◽  
High Strength Aluminum Alloys

In the present investigation, the plasma electrolytic oxidation (PEO) process was employed to form aluminum oxide coating layers to enhance corrosion resistance properties of high-strength aluminum alloys. The formed protective coating layers were examined by means of scanning electron microscopy (SEM) and characterized by several electrochemical techniques, including open circuit potential (OCP), linear potentiodynamic polarization (LP) and electrochemical impedance spectroscopy (EIS). The results were reported in comparison with the bare 6061-O aluminum alloy to determine the corrosion performance of the coated 6061-O alloy. The PEO-treated aluminum alloy showed substantially higher corrosion resistance in comparison with the untreated substrate material. A relationship was found between the coating formation stage, process parameters and the thickness of the oxide-formed layers, which has a measurable influence on enhancing corrosion resistance properties. This study demonstrates promising results of utilizing PEO process to enhance corrosion resistance properties of high-strength aluminum alloys and could be recommended as a method used in industrial applications.

Effect of pH of coating solution on the adhesion strength and corrosion resistance of hydroxyapatite and octacalcium phosphate coated WE43 alloy

2021 ◽  
pp. 088532822110125
Author(s):  
Tuyet Thi Anh Ngo ◽  
Sachiko Hiromoto ◽  
Linh Chi Do ◽  
Hanh Hong Pham ◽  
Le Hanh
Keyword(s):  
Corrosion Resistance ◽  
Adhesion Strength ◽  
Corrosion Current ◽  
Xrd Analysis ◽  
Octacalcium Phosphate ◽  
Solution Deposition ◽  
Chemical Solution Deposition Method ◽  
Before And After ◽  
Coating Layers ◽  
We43 Alloy

Hydroxyapatite (HAp) and octacalcium phosphate (OCP) layers were formed on Mg- 4mass% Y- 3mass% rare earth (WE43) alloy by a chemical solution deposition method at various pH values of pH 5.5, 6.2, 7.5, and 8.6. Adhesion strength of HAp and OCP layers was evaluated before and after immersing in a medium for 14 days by a pull-off test. The corrosion resistance of these coatings was measured by polarization tests performed in a simulated body fluid (SBF). XRD analysis demonstrated that HAp coating layers were formed at pH 7.5 and 8.6, while OCP coating layers were formed at pH 5.5 and 6.2. Adhesion test results showed that the as-coated pH7.5-HAp layer had the highest adhesion strength of 8.6 MPa, which was attributed to the very dense structure of the coating layer. The as-coated pH8.6-HAp layer showed the adhesion strength of 6.5 MPa. The adhesion strength of the as-coated pH5.5- and pH6.2-OCP layers was 3.9 and 7.1 MPa, respectively, that was governed by the thick and fragile property of the layers. After immersing in the medium for 14 days, the adhesion strength of pH7.5- and pH8.6-specimens decreased to 5.8 and 5.6 MPa, respectively. The pitting corrosion and formation of Mg(OH)2 under the HAp layers were responsible for the decrease of adhesion strength. The polarization tests in SBF at 37 °C showed that the corrosion current density decreased with the HAp and OCP coatings, indicating the improvement of the corrosion resistance of WE43 alloy. The HAp coatings improved the corrosion resistance more efficiently than the OCP coatings.

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