The Experts below are selected from a list of 20322 Experts worldwide ranked by ideXlab platform
H G Yang - One of the best experts on this subject based on the ideXlab platform.
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wear and corrosion resistance of al ion implanted az31 Magnesium Alloy
Surface & Coatings Technology, 2007Co-Authors: P Li, H G YangAbstract:Abstract The Al ion implantation into AZ31 Magnesium Alloy is carried out in a MEVVA 80-10 ion implantation system with an ion implantation dose ranging from 2 × 10 16 ions/cm 2 to 1 × 10 17 ions/cm 2 at an ion energy of 40–50 keV. The concentration–depth profile of implanted Al in AZ31 Magnesium Alloy was a Gaussian-type distribution in the depth up to about 840 nm with the maximum Al concentration up to about 10 at.% measured by using Rutherford backscattering spectrometry (RBS). The microstructure, which is composed of α-Mg phase, intermetallic β-Mg 17 Al 12 and MgO phases is observed on the ion implanted samples by X-ray diffraction (XRD). Potentiodynamic anodic polarization curves in 0.01 M NaCl solution with pH = 12 showed that the increase of corrosion potential and pitting breakdown potential and the decrease of the passive current density are obtained for the Al ion implanted samples. The Al ion implanted AZ31 Magnesium Alloy with the ion implantation dose of 2 × 10 16 ions/cm 2 achieved the high pitting breakdown potential to about − 1000 mV(SCE). The wear rate of the Al ion implanted AZ31 Magnesium Alloy is approximately reduced by 30–40%, compared with that of the unimplanted sample.
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wear and corrosion resistance of al ion implanted az31 Magnesium Alloy
Surface & Coatings Technology, 2007Co-Authors: M K Lei, H G Yang, X M ZhuAbstract:Abstract The Al ion implantation into AZ31 Magnesium Alloy is carried out in a MEVVA 80-10 ion implantation system with an ion implantation dose ranging from 2 × 10 16 ions/cm 2 to 1 × 10 17 ions/cm 2 at an ion energy of 40–50 keV. The concentration–depth profile of implanted Al in AZ31 Magnesium Alloy was a Gaussian-type distribution in the depth up to about 840 nm with the maximum Al concentration up to about 10 at.% measured by using Rutherford backscattering spectrometry (RBS). The microstructure, which is composed of α-Mg phase, intermetallic β-Mg 17 Al 12 and MgO phases is observed on the ion implanted samples by X-ray diffraction (XRD). Potentiodynamic anodic polarization curves in 0.01 M NaCl solution with pH = 12 showed that the increase of corrosion potential and pitting breakdown potential and the decrease of the passive current density are obtained for the Al ion implanted samples. The Al ion implanted AZ31 Magnesium Alloy with the ion implantation dose of 2 × 10 16 ions/cm 2 achieved the high pitting breakdown potential to about − 1000 mV(SCE). The wear rate of the Al ion implanted AZ31 Magnesium Alloy is approximately reduced by 30–40%, compared with that of the unimplanted sample.
X M Zhu - One of the best experts on this subject based on the ideXlab platform.
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wear and corrosion resistance of al ion implanted az31 Magnesium Alloy
Surface & Coatings Technology, 2007Co-Authors: M K Lei, H G Yang, X M ZhuAbstract:Abstract The Al ion implantation into AZ31 Magnesium Alloy is carried out in a MEVVA 80-10 ion implantation system with an ion implantation dose ranging from 2 × 10 16 ions/cm 2 to 1 × 10 17 ions/cm 2 at an ion energy of 40–50 keV. The concentration–depth profile of implanted Al in AZ31 Magnesium Alloy was a Gaussian-type distribution in the depth up to about 840 nm with the maximum Al concentration up to about 10 at.% measured by using Rutherford backscattering spectrometry (RBS). The microstructure, which is composed of α-Mg phase, intermetallic β-Mg 17 Al 12 and MgO phases is observed on the ion implanted samples by X-ray diffraction (XRD). Potentiodynamic anodic polarization curves in 0.01 M NaCl solution with pH = 12 showed that the increase of corrosion potential and pitting breakdown potential and the decrease of the passive current density are obtained for the Al ion implanted samples. The Al ion implanted AZ31 Magnesium Alloy with the ion implantation dose of 2 × 10 16 ions/cm 2 achieved the high pitting breakdown potential to about − 1000 mV(SCE). The wear rate of the Al ion implanted AZ31 Magnesium Alloy is approximately reduced by 30–40%, compared with that of the unimplanted sample.
P Li - One of the best experts on this subject based on the ideXlab platform.
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wear and corrosion resistance of al ion implanted az31 Magnesium Alloy
Surface & Coatings Technology, 2007Co-Authors: P Li, H G YangAbstract:Abstract The Al ion implantation into AZ31 Magnesium Alloy is carried out in a MEVVA 80-10 ion implantation system with an ion implantation dose ranging from 2 × 10 16 ions/cm 2 to 1 × 10 17 ions/cm 2 at an ion energy of 40–50 keV. The concentration–depth profile of implanted Al in AZ31 Magnesium Alloy was a Gaussian-type distribution in the depth up to about 840 nm with the maximum Al concentration up to about 10 at.% measured by using Rutherford backscattering spectrometry (RBS). The microstructure, which is composed of α-Mg phase, intermetallic β-Mg 17 Al 12 and MgO phases is observed on the ion implanted samples by X-ray diffraction (XRD). Potentiodynamic anodic polarization curves in 0.01 M NaCl solution with pH = 12 showed that the increase of corrosion potential and pitting breakdown potential and the decrease of the passive current density are obtained for the Al ion implanted samples. The Al ion implanted AZ31 Magnesium Alloy with the ion implantation dose of 2 × 10 16 ions/cm 2 achieved the high pitting breakdown potential to about − 1000 mV(SCE). The wear rate of the Al ion implanted AZ31 Magnesium Alloy is approximately reduced by 30–40%, compared with that of the unimplanted sample.
M K Lei - One of the best experts on this subject based on the ideXlab platform.
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wear and corrosion resistance of al ion implanted az31 Magnesium Alloy
Surface & Coatings Technology, 2007Co-Authors: M K Lei, H G Yang, X M ZhuAbstract:Abstract The Al ion implantation into AZ31 Magnesium Alloy is carried out in a MEVVA 80-10 ion implantation system with an ion implantation dose ranging from 2 × 10 16 ions/cm 2 to 1 × 10 17 ions/cm 2 at an ion energy of 40–50 keV. The concentration–depth profile of implanted Al in AZ31 Magnesium Alloy was a Gaussian-type distribution in the depth up to about 840 nm with the maximum Al concentration up to about 10 at.% measured by using Rutherford backscattering spectrometry (RBS). The microstructure, which is composed of α-Mg phase, intermetallic β-Mg 17 Al 12 and MgO phases is observed on the ion implanted samples by X-ray diffraction (XRD). Potentiodynamic anodic polarization curves in 0.01 M NaCl solution with pH = 12 showed that the increase of corrosion potential and pitting breakdown potential and the decrease of the passive current density are obtained for the Al ion implanted samples. The Al ion implanted AZ31 Magnesium Alloy with the ion implantation dose of 2 × 10 16 ions/cm 2 achieved the high pitting breakdown potential to about − 1000 mV(SCE). The wear rate of the Al ion implanted AZ31 Magnesium Alloy is approximately reduced by 30–40%, compared with that of the unimplanted sample.
Zhonghao Jiang - One of the best experts on this subject based on the ideXlab platform.
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electroless deposition of ni w p coating on az91d Magnesium Alloy
Applied Surface Science, 2007Co-Authors: Wanxi Zhang, Zhonghao Jiang, N Huang, Q Jiang, Jianshe LianAbstract:Abstract Ternary Ni–W–P Alloy coating was deposited directly on AZ91D Magnesium Alloy by using an alkaline-citrate-based baths. Nickel sulfate and sodium tungstate were used as metal ion sources, respectively, and sodium hypophosphite was used as a reducing agent. The pH value of the electroless bath was tailored for Magnesium Alloy. The coating was characterized for its structure, morphology, microhardness and the corrosion properties. SEM observation showed the presence of dense and coarse nodules in the ternary coating. EDS analysis showed that the content of tungsten in the Ni–W–P Alloy was 4.5 wt.%. Both the electrochemical analysis and the immersion test in 10% HCl solution revealed that the ternary Ni–W–P coating exhibited good corrosion resistance properties in protecting the AZ91D Magnesium Alloy.
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growth of zinc phosphate coatings on az91d Magnesium Alloy
Surface & Coatings Technology, 2006Co-Authors: Guangyu Li, Zhonghao Jiang, Jianshe Lian, Qing JiangAbstract:Zinc phosphate coating was formed on AZ91D Magnesium Alloy through a phosphating bath where H3PO4, ZnO, Zn(NO3)2 and NaF were applied. Chlorate (NaClO3) was used as an accelerator of phosphatization to replace nitrite. The coating compositions were hopeite (Zn3 (PO4)2·4H2O) and Zn. The growth process of the phosphate film on the Magnesium Alloy substrate was investigated by SEM observation and XRD analysis. In the early stage (0–60 s) of phosphatization, both hopeite and metallic zinc nucleated and grew together on the substrate to form flower structure. A great number and uniform nucleation of hopeite and metallic zinc implied that they formed on the β and α phases of the AZ91D Magnesium Alloy simultaneously. Afterwards, because Magnesium Alloy substrate was almost fully covered, only hopeite deposited continuously to form slab-like structure. The formed zinc phosphate coatings exhibited high corrosion resistance in 5% NaCl solution as shown by polarization measurement.
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high corrosion resistance nanocrystalline ni coating on az91d Magnesium Alloy
Surface & Coatings Technology, 2006Co-Authors: C D Gu, Zhonghao Jiang, Jianshe Lian, Jinguo He, Qing JiangAbstract:Nanocrystalline (nc) Ni coating was direct-current electrodeposited on the AZ91D Magnesium Alloy substrate aimed to improve its corrosion resistance using a direct electroless plating of nickel as the protective layer. As comparison, two electroless Ni coatings on the Magnesium Alloy with different thickness were also presented in the paper. The surface morphologies of the coatings were studied by SEM and FESEM. The nc Ni coating had an average grain size of about 40 nm and an evident {200} preferred texture revealed by XRD. The hardness of the nc Ni coating was about 580 VHN, which was far higher than that (about 100 VHN) of the AZ91D Magnesium Alloy substrate. The electrochemical measurements showed that the nc Ni coating on the Magnesium Alloy had the lowest corrosion current density and most positive corrosion potential among the studied coatings on the Magnesium Alloy. Furthermore, the nc Ni coating on the AZ91D Magnesium Alloy exhibited very high corrosion resistance in the rapid corrosion test illustrated in the paper. The reasons for an increase in the corrosion resistance of the nc Ni coating on the Magnesium Alloy should be attributable to its fine grain structure and the low porosity in the coating.
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electroless ni p plating on az91d Magnesium Alloy from a sulfate solution
Journal of Alloys and Compounds, 2005Co-Authors: Jianshe Lian, Liyuan Niu, Zhonghao JiangAbstract:Direct electroless Ni–P plating on the AZ91D Magnesium Alloy from a plating bath containing sulfate nickel was investigated in the paper. The nucleation mechanism of Ni–P deposits on the AZ91D Magnesium Alloy was studied by using XRD and SEM. The electroless Ni–P deposits were preferentially nucleated on the -Mg17Al12 phase and extended to the primary and eutectic phases of the AZ91D Magnesium Alloy. The effect of the acid pickle treatment time of the AZ91D Magnesium Alloy substrate on the electroless Ni–P plating was also investigated. With prolonging the acid pickle treatment time, the cluster of electroless Ni–P deposition became smaller and the deposits were found to be more compact. The deposition rate of electroless Ni–P plating was proportional to the acid pickle treatment time. The hardness values of the Ni–P coatings were about 660 VHN and were not influenced by the pretreatments. © 2004 Elsevier B.V. All rights reserved.
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electroless ni p plating on az91d Magnesium Alloy from a sulfate solution
Journal of Alloys and Compounds, 2005Co-Authors: C D Gu, Guangyu Li, Jianshe Lian, Liyuan Niu, Zhonghao JiangAbstract:Direct electroless Ni–P plating on the AZ91D Magnesium Alloy from a plating bath containing sulfate nickel was investigated in the paper. The nucleation mechanism of Ni–P deposits on the AZ91D Magnesium Alloy was studied by using XRD and SEM. The electroless Ni–P deposits were preferentially nucleated on the -Mg17Al12 phase and extended to the primary and eutectic phases of the AZ91D Magnesium Alloy. The effect of the acid pickle treatment time of the AZ91D Magnesium Alloy substrate on the electroless Ni–P plating was also investigated. With prolonging the acid pickle treatment time, the cluster of electroless Ni–P deposition became smaller and the deposits were found to be more compact. The deposition rate of electroless Ni–P plating was proportional to the acid pickle treatment time. The hardness values of the Ni–P coatings were about 660 VHN and were not influenced by the pretreatments. © 2004 Elsevier B.V. All rights reserved.
