汽车用镁合金磷化处理及化学镀Ni-Sn-P合金镀层

Phosphating Treatment and Electroless Plating of Ni-Sn-P Alloy Coating on Magnesium Alloy for Automobile

先对汽车用AZ31B镁合金进行了磷化处理,然后在磷化膜表面化学镀Ni-Sn-P合金镀层,并对化学镀Ni-Sn-P合金镀层的成分、表面形貌及耐蚀性等进行了研究。研究发现:镁合金磷化属于一种磷化膜生成和溶解的动态过程。磷化膜较为均匀、致密,存在少量微裂纹,厚度约为6μm。化学镀Ni-Sn-P合金镀层由大量均匀、致密的胞状颗粒堆积而成。经过磷化和化学镀Ni-Sn-P合金镀层后,镁合金的耐蚀性显著提高。

Phosphating treatment of AZ31B magnesium alloy for automobile was carried out,and Ni-Sn-P alloy coating was prepared on the surface of phosphating film by electroless plating.The composition,surface morphology and corrosion resistance of electroless Ni-Sn-P alloy coating were investigated.It was found that magnesium alloy phosphating was a dynamic process of formation and dissolution of phosphating film.The phosphating film was relatively uniform and compact,with a few microcracks and a thickness of 6μm.The electroless Ni-Sn P alloy coating was composed of a large number of uniform and dense cellular particles.After phosphating treatment and electroless plating of Ni Sn P alloy coating,the corrosion resistance of magnesium alloy was significantly improved.