Deposition of electroless Ni-P/Ni-W-P duplex coatings on AZ91D magnesium alloy

来源期刊：中国有色金属学报(英文版)2008年增刊第1期

论文作者：陈晓明 李光玉 连建设

文章页码：323 - 328

Key words：corrosion resistance; electroless deposition; Ni-W-P alloy; acid-sulfate nickel

Abstract: The electroless Ni-P/Ni-W-P duplex coatings were deposited directly on AZ91D magnesium alloy by an acid-sulfate nickel bath. Nickel sulphate and sodium tungstate were used as metal ion sources and sodium hypophosphite was used as reducing agent. The coating was characterized for its structure, morphologies, microhardness and corrosion properties. The presence of dense and coarse nodules in the duplex coatings was observed by SEM and EDS. Tungsten content in Ni-P/Ni-W-P alloy is about 0.65%(mass fraction) and the phosphorus content is 8.18%(mass fraction). The microhardness of the coatings is 622 VHN. The coating shows good adhesion to the substrate. The results of electrochemical analysis, the porosity and the immersion test show that Ni-P/Ni-W-P duplex coatings possess noble anticorrosion properties to protect the AZ91D magnesium alloy.

基金信息：the 2007 Science and Technology Support Plan of Changchun City, China