Corrosion Behavior of Rare Earth Cerium Based Trivalent Chromium Conversion Coating on Zinc

2014 ◽  
Vol 881-883 ◽  
pp. 1165-1170 ◽  
Author(s):  
Shu Ting Miao ◽  
Sheng Han ◽  
Lifeng Hao
Keyword(s):  
Electron Microscopy ◽  
Corrosion Resistance ◽  
Rare Earth ◽  
Electrochemical Method ◽  
Trivalent Chromium ◽  
Conversion Coating ◽  
Passivation Film ◽  
Good Corrosion Resistance ◽  
Scanning Electron ◽  
Cerium Hydroxide

The present paper focused on the use of the salt of rare earth cerium as corrosion inhibitor of Zinc by using cathodic electrolytic passivation method. The corrosion resistance and the microphology of the cerium passivation film were studied by the methods of electrochemical method, scanning electron microscopy (SEM). From the results, it was shown that good corrosion resistance of cerium-based trivalent chromium conversion coating was obtained when the compositions were as follows: Ce (SO4)2, 6g/L; Cr2(SO4)3, 18.9g/L and NaNO3; current density, 2A/dm2; temperature, 40 oC; time, 60s. SEM revealed that the cerium trivalent chromium conversion coatings formed uniform cerium hydroxide and chrimuim hydroxide deposition on the surface of Zinc.

Research of Anti-Corrosion of Armour Steel in Surface Chromate Conversion Coating

2013 ◽  
Vol 734-737 ◽  
pp. 2332-2337
Author(s):  
Rui Hua Guo ◽  
Fang Sheng Liu ◽  
Lin Min Wang
Keyword(s):  
Corrosion Resistance ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Electrochemical Method ◽  
Electrochemical Corrosion ◽  
Conversion Coating ◽  
Chromate Conversion Coating ◽  
Conversion Time ◽  
Armour Steel ◽  
The Rare Earth

This article by orthogonal experimental method to determine the composition of chromate conversion and use of electrochemical method of electrochemical corrosion of the film discussed the substrate in different components, content, time and pH of chromate conversion coating of corrosion resistance. Orthogonal to determine the best experimental chromate conversion solution by adding the rare earth element cerium and lanthanum salt, and discuss the effects of rare earth elements cerium and lanthanum chromate conversion film on the anti-corrosion. The results show that in CrO3 5.4 g/L, NaF 0.5 g/L, K3Fe (CN)6 0.5 g/L, pH 1, conversion time is three minutes, there is a better corrosion resistance. The rare earth elements in a chromate conversion solution, La2(CO3)3 to 0.2 g/L chromate conversion coating of the anti-corrosion better.

Study on Technological Process of Cerium-Based Conversion Coating on Aluminum

2009 ◽  
Vol 79-82 ◽  
pp. 879-882
Author(s):  
Ji Hui Xu ◽  
Xin Wang ◽  
Jing Wang ◽  
Qiu Ju Zheng
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Corrosion Resistance ◽  
Technological Process ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Measurement ◽  
Conversion Coating ◽  
X Ray ◽  
Scanning Electron ◽  
Industrial Aluminum

The Cerium-based conversion coating is formed on the industrial aluminum(1060) by using chemical immersion. The microstructures of the conversion coating have been examined by scanning electron microscopy(SEM). The electrochemical measurement result shows that the corrosion resistance of aluminum is significantly improved after the conversion coating was formed. The result of X-ray photoelectron spectroscopy (XPS) shows that the cerium conversion coating mainly consisted of oxide of aluminum, CeO2 and TiO2. The formation mechanism of the Cerium-based conversion coating is investigated.

Influence of Fly Ash on Corrosion Resistance of Refractory Forsterite-Spinel Ceramics

2021 ◽  
Vol 325 ◽  
pp. 181-187
Author(s):  
Martin Nguyen ◽  
Radomír Sokolář
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Corrosion Resistance ◽  
Fly Ash ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transition Zones ◽  
Refractory Ceramics ◽  
Scanning Electron

This article examines the influence of fly ash on corrosion resistance of refractory forsterite-spinel ceramics by molten iron as a corrosive medium. Fly ash in comparison with alumina were used as raw materials and sources of aluminium oxide for synthesis of forsterite-spinel refractory ceramics. Raw materials were milled, mixed in different ratios into two sets of mixtures and sintered at 1550°C for 2 hours. Samples were characterized by X-ray diffraction analysis and thermal dilatometric analysis. Crucibles were then made from the fired ceramic mixtures and fired together with iron at its melting point of 1535°C for 5 hours. The corrosion resistance was evaluated by scanning electron microscopy on the transition zones between iron and ceramics. Mixtures with increased amount of spinel had higher corrosion resistance and mixtures with fly ash were comparable to mixtures with alumina in terms of corrosion resistance and refractory properties.

scholarly journals SEM, EDS and Electrical Capacitance Study on Electrodeposited Ni-Cu Layers

2019 ◽  
Vol 70 (9) ◽  
pp. 3210-3212
Author(s):  
Oana Claudia Ciobotea Barbu ◽  
Ioana Alina Ciobotaru ◽  
Anca Cojocaru ◽  
Florin Mihai Benga ◽  
Danut Ionel Vaireanu
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Chemical Composition ◽  
Electrochemical Method ◽  
Steel Substrate ◽  
Distilled Water ◽  
Electrical Capacitance ◽  
Nickel Copper ◽  
Scanning Electron

Nickel-Copper metallic layers were deposited onto a steel substrate by using the electrochemical method. The morphology and the chemical composition of the deposited layers were studied by scanning electron microscopy. The electrical capacitance was measured on a functional supercapacitor made of two Ni-Cu deposited layers and a Nafion 117� membrane hydrated with distilled water, which served as a dielectric separator.

Electrochemical Synthesis and Photocatalytic Activity of Differently Shaped CuOx Particles

2017 ◽  
Vol 13 ◽  
pp. 330-333
Author(s):  
Anna Ulyankina ◽  
Igor Leontyev ◽  
Nina Smirnova
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Electrochemical Method ◽  
Spherical Particles ◽  
Photocatalytic Efficiency ◽  
X Ray Diffraction ◽  
X Ray ◽  
Polyhedral Particles ◽  
Copper Electrodes ◽  
Scanning Electron

CuOx powders with diff erently shaped particles were firstly prepared via an electrochemical method by oxidation and dispersion of copper electrodes in an electrolyte solution under pulse alternating current (PAC). By means of X-ray diffraction (XRD) and scanning electron microscopy (SEM) the current density is found to have an influence on the morphology and composition of CuOx particles. Photocatalytic efficiency of CuOx towards methyl orange (MO) degradation under visible light was investigated. The prepared polyhedral particles show the best photocatalytic activity of 81 % towards MO comparing to octahedral and spherical particles with 70 and 61 %, respectively.

scholarly journals Standard Hot Pressing as a Possible Solution to Obtain Dense K0.5Na0.5NbO3 Ceramic Doped by Er2O3 and Yb2O3

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4171 ◽  
Author(s):  
Paweł Rutkowski ◽  
Jan Huebner ◽  
Adrian Graboś ◽  
Dariusz Kata ◽  
Dariusz Grzybek ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Rare Earth ◽  
Phase Composition ◽  
Powder Mixture ◽  
Hot Pressing ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ultrasonic Methods ◽  
Scanning Electron

In this study, the influence of the addition of rare earth oxides on the phase composition and density of KNN piezoelectric ceramics was investigated. The initial powders of Na2CO3 and K2CO3 were dried at 150 °C for 2 h. Then, a powder mixture for synthesis was prepared by adding a stoichiometric amount of Nb2O5 and 5 and 10 wt % overabundance of Na2CO3. All powders were mixed by ball-milling for 24 h and synthesized at 950 °C. The phase composition of the reaction bed was checked by means of X-ray diffraction (XRD). It had an appearance of tetragonal and monoclinic K0.5Na0.5NbO3 (KNN) phases. Then, 1 and 2 wt % of Er2O3 and Yb2O3, were added to the mixture. Green samples of 25 mm diameter and 3 mm thickness were prepared and sintered by hot pressing at 1000 °C for 2 h under 25 MPa pressure. The final samples were investigated via scanning electron microscopy (SEM)-energy-dispersive X-ray spectroscopy (EDS), XRD, Rietveld, and ultrasonic methods. Phase analysis showed tetragonal and orthorhombic KNN phases, and a contamination of (K2CO3·1.5H2O) was present. The obtained KNN polycrystals had a relative density above 95%. Texturing of the material was confirmed as a result of hot pressing.

Catechol/polyethyleneimine conversion coating with enhanced corrosion protection of magnesium alloys: potential applications for vascular implants

2018 ◽  
Vol 6 (43) ◽  
pp. 6936-6949 ◽  
Author(s):  
Hao Zhang ◽  
Lingxia Xie ◽  
Xiaolong Shen ◽  
Tengda Shang ◽  
Rifang Luo ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Surface Modification ◽  
Magnesium Alloys ◽  
Corrosion Protection ◽  
Conversion Coating ◽  
Good Corrosion Resistance ◽  
Potential Applications

A catechol/polyethyleneimine conversion coating on a MgZnMn alloy possessed good corrosion resistance. Heparin was further grafted on it and this showed the potential for surface modification of magnesium-based vascular implants.

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