采用磷酸为主要成分的溶液取代传统的铬酸加氢氟酸对镁合金进行活化处理，然后直接化学镀镍；用SEM/EDAX考察了无铬无氟前处理转化膜和化学镀镍沉积层的形貌、成分.结果表明，无铬无氟转化膜主要由磷酸镁组成，化学镀镍层表面较均匀、致密、无明显缺陷.经热处理后，镀层和基体的结合强度超过23 MPa.动电位极化测试结果表明，镀层体系的自腐蚀电位约为-0.36 V(SCE)，有明显的钝化区间，对基体镁合金起到较好的防护作用.
A phosphorizing process was proposed as the pretreatment of magnesium alloy for nickel electroless plating to replace the traditional pretreatment with bathes containing chrome and fluorine.The subsequent nickel plating deposited on the phosphorized magnesium alloy was then characterized by observation of surface morphology,examination of adhesion and corrosion resistance.The pretreatment can clearly reduce the corrosion of magnesium substrate during Ni-P plating process.The potentiodynamic polarization tests indicated that the corrosion current density of Ni-P plating on AZ91 pretreated by phosphorizing process decreased by almost one order of magnitude compared to those pretreated by traditional bathes containing chrome and fluorine.After a proper heat treatment the adhesion strength of the Ni-P plating on the phosphorized substrate can reach above 23 MPa.More importantly,the new technique does not use Cr6+ and HF in its pretreatment,therefore is a much environmentally friendly process.
参考文献
| [1] |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%