{"title":"Electroless Ni-P Plating on AZ91D Magnesium Alloy with a New Homogenization Pretreatment","authors":"Can Sun, Xingwu Guo, Shaohua Wang, W. Ding","doi":"10.11903/1002.6495.2013.256","DOIUrl":null,"url":null,"abstract":"A new environment-friendly homogenization pretreatment process was adopted for the electroless nickel plating on AZ91D magnesium alloy. Then, the morphologies, chemical composition and microstructure of the pretreated layer and the formed Ni-P coating were studied using scanning electronic microscopy(SEM), energy-dispersive X-ray spectroscopy(EDS) and X-ray diffraction spectroscopy(XRD). It was indicated that a dense Zn film formed on the substrate surface after the homogenization pretreatment, due to the selective removal of β phase during the processing.As the result, the subsequently formed Ni-P coating was uniform, compact and defect-free with P content around 7.0%, which was characterized as an amorphous matter by XRD. Potentiodynamic polarization and electrochemical impedance spectroscopy(EIS) tests revealed that the Ni-P coating could significantly improve the corrosion resistance of AZ91D magnesium alloy with an obvious positive shifting of corrosion potential by 1.136 V and a dramatic reduce of corrosion current density by two orders of magnitude. Furthermore the obtained Ni-P coating showed excellent adhesion to AZ91D substrate.","PeriodicalId":10727,"journal":{"name":"Corrosion Science and Protection Technology","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2014-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Corrosion Science and Protection Technology","FirstCategoryId":"1087","ListUrlMain":"https://doi.org/10.11903/1002.6495.2013.256","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"Chemical Engineering","Score":null,"Total":0}
引用次数: 0
Abstract
A new environment-friendly homogenization pretreatment process was adopted for the electroless nickel plating on AZ91D magnesium alloy. Then, the morphologies, chemical composition and microstructure of the pretreated layer and the formed Ni-P coating were studied using scanning electronic microscopy(SEM), energy-dispersive X-ray spectroscopy(EDS) and X-ray diffraction spectroscopy(XRD). It was indicated that a dense Zn film formed on the substrate surface after the homogenization pretreatment, due to the selective removal of β phase during the processing.As the result, the subsequently formed Ni-P coating was uniform, compact and defect-free with P content around 7.0%, which was characterized as an amorphous matter by XRD. Potentiodynamic polarization and electrochemical impedance spectroscopy(EIS) tests revealed that the Ni-P coating could significantly improve the corrosion resistance of AZ91D magnesium alloy with an obvious positive shifting of corrosion potential by 1.136 V and a dramatic reduce of corrosion current density by two orders of magnitude. Furthermore the obtained Ni-P coating showed excellent adhesion to AZ91D substrate.