The Experts below are selected from a list of 103260 Experts worldwide ranked by ideXlab platform
Rongchang Zeng - One of the best experts on this subject based on the ideXlab platform.
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Corrosion Resistance of glucose induced hydrothermal calcium phosphate coating on pure magnesium
Applied Surface Science, 2019Co-Authors: Lingyu Li, Rongchang Zeng, Shuoqi Li, Xiaobo Chen, Zhenlin WangAbstract:Abstract Glucose-induced composite coatings containing crystalline calcium phosphate and Mg(OH)2 interlayer were prepared on pure Mg substrate through hydrothermal deposition from alkaline solution. Surface composition, morphology and Corrosion Resistance of the coatings were characterized through XRD, FTIR, SEM, XPS, electrochemical and hydrogen evolution measurements. Results reveal that calcium phosphate coatings were composed of dicalcium phosphate anhydrous, calcium-deficient hydroxyapatite and hydroxyapatite. Corrosion Resistance of pure Mg specimens was improved by the formation of such a calcium phosphate coating. The findings provide a novel strategy to design calcium phosphate conversion coatings with satisfactory Corrosion Resistance for biodegradable Mg implants.
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Corrosion Resistance of bioinspired DNA-induced Ca–P coating on biodegradable magnesium alloy
KeAi, 2019Co-Authors: Ping Liu, Rongchang Zeng, Xiaobo Chen, Jia-min Wang, Dong-chu Chen, Shao-kang Guan, Lan-yue CuiAbstract:Bioinspired coatings with decreased Corrosion rate and enhanced bond strength are at the core of future clinic applications on degradable magnesium (Mg)-based implants. The hybrid of organic and inorganic compounds offers a strategy to fabricate biodegradable, biocompatible and compact coatings on biomedical Mg alloys. Hereby, a comparison with and without DNA addition was made on the Corrosion Resistance and adhesion strength of Ca–P coatings fabricated on AZ31 alloy via hydrothermal deposition. The morphology, chemical composition, and crystallographic structure of the coatings were investigated by means of SEM, EDS and FTIR as well as XRD before and after Corrosion tests. Corrosion Resistance was evaluated via potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS) and hydrogen evolution tests in Hank's solution. Results show that the coatings are mainly characterized by tricalcium phosphate (TCP), dicalcium phosphate anhydrous (DCPA) and calcium-deficient hydroxyapatite (CDHA). The presence of DNA leads to the formation of Ca–P coating with improved Corrosion Resistance and adhesion strength. Additionally, the formation mechanism for DNA-induced Ca–P coating is proposed. The DNA-induced Ca–P coating exhibits a promising future for controlling the Corrosion rate of biodegradable Mg alloys. Keywords: DNA, Corrosion Resistance, Biodegradability, Magnesium alloys, Coating
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Corrosion Resistance of ceria polymethyltrimethoxysilane modified magnesium hydroxide coating on az31 magnesium alloy
Surface & Coatings Technology, 2017Co-Authors: Lian Guo, Rongchang Zeng, Fen Zhang, Liang Song, Enhou HanAbstract:Abstract A magnesium hydroxide/polymethyltrimethoxysilane (PMTMS)/CeO2 hybrid coating was fabricated via hydrothermal treatment method and subsequent sealing with PMTMS and CeO2. The surface morphologies, wettability, microstructures and chemical compositions of the samples were investigated using FE-SEM, FT-IR, XRD, XPS and contact angle (CA). The Corrosion Resistance of the composite coatings was evaluated using the electrochemical and hydrogen evolution measurements. The results demonstrated that the magnesium hydroxide coating was sealed by the PMTMS and CeO2. The Mg(OH)2/PMTMS/CeO2 coating had a thickness of approximately 12.86 ± 0.01 μm and significantly enhanced the Corrosion Resistance of the AZ31 alloy. The influence of the existence of the ceria on the Corrosion Resistance was investigated. Additionally, a Corrosion mechanism of the coating was proposed and discussed.
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Corrosion Resistance of silane modified hydroxide zinc carbonate film on az31 magnesium alloy
Acta Metallurgica Sinica (english Letters), 2015Co-Authors: Rongchang Zeng, Liju Liu, Tingting Pang, Fe Zhang, Weiwei Zhang, Hongzhi CuiAbstract:The Corrosion Resistance of magnesium alloys can be improved using functional surface modification such as hydrophobic treatment. In this study, a hierarchical hydroxide zinc carbonate (HZC) film was fabricated on AZ31 magnesium alloy via a simple chemical-bath deposition process using urea aqueous solution. The morphologies, compositions and Corrosion Resistance of the hydrophobic film were analyzed using scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectrometer, and electrochemical measurements as well. The results revealed that the HZC film displayed flower-like protrusions and had a thickness of approximately 100 μm. The fluoroalkylsilane (FAS)-modified HZC film exhibited a hydrophobic property with a water contact angle of 131.3°. The FAS/HZC film significantly improved the Corrosion Resistance of the AZ31 alloy due to hierarchical structures and hydrophobic modification.
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Corrosion Resistance of mg al ldh coating on magnesium alloy az31
Surface & Coatings Technology, 2014Co-Authors: Fen Zhang, Rongchang Zeng, Hongzhi Cui, Liang Song, Zhenguo Liu, Enhou HanAbstract:Mg-Al-layered double hydroxide (LDH) coatings were fabricated by a combined co-precipitation method and hydrothermal process on an AZ31 alloy substrate. The characteristics of the coatings were investigated using SEM, XRD, FT-IR and EDS. The Corrosion Resistance of the LDH coatings was studied using potentiodynamic polarization and electrochemical impedance spectrum. The results demonstrated that the LDH coatings, characterized by nanoplates stacked vertically to the substrate surface and ion-exchange ability, possess excellent Corrosion Resistance. (C) 2014 Elsevier B.V. All rights reserved.
Xiufang Cui - One of the best experts on this subject based on the ideXlab platform.
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microstructure and Corrosion Resistance of phytic acid conversion coatings for magnesium alloy
Applied Surface Science, 2008Co-Authors: Fuhui Wang, Xiufang Cui, Guo Jin, M H DingAbstract:In this paper, a new innoxious and pollution-free chemical protective coating for magnesium alloys, phytic acid conversion coating, was prepared. The conversion coatings are found to have high cover ratio and no cracks are found by atomic force microscopes (AFM) and scanning electronmicroscopy (SEM). The main elements of the conversion coatings are Mg, Al, O, P and C by X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). The chemical state of the elements in the coatings was also investigated by Fourier transform infrared spectroscopy (FTIR). AES depth pro. le analysis suggests that the thickness of the conversion coating is about 340 nm. The Corrosion Resistance of the coatings was evaluated by polarization curves. The results indicate that the Corrosion Resistance for the conversion coated AZ91D magnesium alloys in 3.5% NaCl solution increases markedly. The mechanisms of Corrosion Resistance and coatings formation are also discussed. (C) 2008 Elsevier B. V. All rights reserved.
Laichang Zhang - One of the best experts on this subject based on the ideXlab platform.
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improved Corrosion Resistance on selective laser melting produced ti 5cu alloy after heat treatment
ACS Biomaterials Science & Engineering, 2018Co-Authors: Peng Qin, Yujing Liu, T B Sercombe, Chuanwei Zhang, Chongde Cao, Hongqi Sun, Laichang ZhangAbstract:A Ti-5Cu alloy produced by selective laser melting exhibits a nonuniform Ti2Cu phase structure, which contains a small amount of α′ phase in melt pool boundaries thereby resulting in reduced Corrosion Resistance. The heat-treatment process proposed in this work eliminates the deleterious effect of α′ phase and the Ti2Cu phase is refined using different cooling rates, which improves the Corrosion Resistance. The electrochemical results indicate that the heat-treated Ti-5Cu samples have similar Corrosion behavior to pure CP-Ti. A slower cooling rate produces a larger spacing between the Ti2Cu phases in the microstructure of the sample, resulting in higher Corrosion Resistance. The Corrosion behavior of SLM-produced Ti-5Cu and heat-treated counterparts with different microstructure are detailed discussed.
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distinction in Corrosion Resistance of selective laser melted ti 6al 4v alloy on different planes
Corrosion Science, 2016Co-Authors: Nianwei Dai, Laichang Zhang, Junxi Zhang, Xin Zhang, Yang Chen, Chao YangAbstract:Abstract Electrochemical measurements and microstructural analysis were performed to study the Corrosion Resistance of different planes of Ti-6Al-4V alloy manufactured by selective laser melting (SLM). The electrochemical results suggest that its XY-plane possesses a better Corrosion Resistance compared to XZ-plane in 1 M HCl solution, in spite of slight difference in 3.5 wt.% NaCl solution, suggesting that the different planes exhibit more pronounced distinction in Corrosion Resistance in harsher solution system. The inferior Corrosion Resistance of XZ-plane is attributed to the presence of more α⿲ martensite and less β-Ti phase in microstructure for XZ-plane than for XY-plane of the SLM-produced Ti-6Al-4V alloy.
Huang Weidong - One of the best experts on this subject based on the ideXlab platform.
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study on the Corrosion Resistance of phytic acid conversion coating for magnesium alloys
Surface & Coatings Technology, 2006Co-Authors: Liu Jianrui, Guo Yina, Huang WeidongAbstract:Abstract Chemical conversion treatment is a basic method to improve the Corrosion Resistance of magnesium and its alloys. In the method of conventional conversion, however, the solution contains hexavalent chromium compounds which are harmful to the environment. The replacement surface treatment has been strongly emphasized in recent years. A chemical conversion treatment solution containing phytic was developed in this study for magnesium alloys. The surface conversion coating was characterized by SEM and EDS. The factors of influence to the Corrosion Resistance of conversion coating were discussed through hydrogen evolution method and polarization potential. The Corrosion Resistance of phytic acid conversion coating was comparable with the chromate containing. The experimental results indicate that the phytic acid conversion coating had better Corrosion Resistance when magnesium alloy was treated with a solution containing 0.5% to 1% phytic acid at temperature 25 to 60 °C and pH value at the range of 3∼5 for 30 to 60 min.
Hongzhi Cui - One of the best experts on this subject based on the ideXlab platform.
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Corrosion Resistance of silane modified hydroxide zinc carbonate film on az31 magnesium alloy
Acta Metallurgica Sinica (english Letters), 2015Co-Authors: Rongchang Zeng, Liju Liu, Tingting Pang, Fe Zhang, Weiwei Zhang, Hongzhi CuiAbstract:The Corrosion Resistance of magnesium alloys can be improved using functional surface modification such as hydrophobic treatment. In this study, a hierarchical hydroxide zinc carbonate (HZC) film was fabricated on AZ31 magnesium alloy via a simple chemical-bath deposition process using urea aqueous solution. The morphologies, compositions and Corrosion Resistance of the hydrophobic film were analyzed using scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectrometer, and electrochemical measurements as well. The results revealed that the HZC film displayed flower-like protrusions and had a thickness of approximately 100 μm. The fluoroalkylsilane (FAS)-modified HZC film exhibited a hydrophobic property with a water contact angle of 131.3°. The FAS/HZC film significantly improved the Corrosion Resistance of the AZ31 alloy due to hierarchical structures and hydrophobic modification.
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Corrosion Resistance of mg al ldh coating on magnesium alloy az31
Surface & Coatings Technology, 2014Co-Authors: Fen Zhang, Rongchang Zeng, Hongzhi Cui, Liang Song, Zhenguo Liu, Enhou HanAbstract:Mg-Al-layered double hydroxide (LDH) coatings were fabricated by a combined co-precipitation method and hydrothermal process on an AZ31 alloy substrate. The characteristics of the coatings were investigated using SEM, XRD, FT-IR and EDS. The Corrosion Resistance of the LDH coatings was studied using potentiodynamic polarization and electrochemical impedance spectrum. The results demonstrated that the LDH coatings, characterized by nanoplates stacked vertically to the substrate surface and ion-exchange ability, possess excellent Corrosion Resistance. (C) 2014 Elsevier B.V. All rights reserved.
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Corrosion Resistance of calcium modified zinc phosphate conversion coatings on magnesium aluminium alloys
Corrosion Science, 2014Co-Authors: Rongchang Zeng, Fe Zhang, Hongzhi CuiAbstract:Abstract The influence of the microstructure of the calcium-modified zinc phosphate (Zn–Ca–P) conversion coatings of Mg–Al alloys on Corrosion Resistance was investigated using OM and SEM and hydrogen evolution tests. The results demonstrated that the Zn–Ca–P coatings markedly enhanced the Corrosion Resistance of the alloys. The microstructure and chemical compositions of the alloys exerted a significant influence on the Corrosion Resistance of their coatings. A model was proposed to elucidate the formation mechanism of the porous Zn–Ca–P coating on the AM30 alloy.
