摘要
为了改进传统的镁合金化学镀镍前处理工艺和确定以硫酸镍为主盐的镁合金化学镀镍的最佳工艺。采用碱性焦磷酸盐进行浸蚀代替铬酸浸蚀,去除合金表面的油污和氧化物;然后用氢氟酸溶液进行活化。通过正交试验确定了化学镀镍的最佳工艺。结果表明:采用碱性焦磷酸盐浸蚀的前处理工艺、在最佳施镀条件下镀2h,镀层厚度达到20μm,与基体结合良好;镀层为N i-P微晶,表面平整、致密,磷的质量分数达11.7%。在质量分数为3.5%的NaC l溶液中的动电位极化测试结果表明,镀层可对AZ91D镁合金起到良好的防护作用。
In order to improve the traditional pretreatment process of electroless nickel plating on mag- nesium alloys and determine the plating bath with sulphate as nickel source, the chromic acid pickling is replaced with alkaline pyrophosphate pickling. The oil and oxides on the specimen are detached by the alkaline pyrophosphate pickling, then the specimen is activated in the HF solution. The optimal process of electroless nickel plating on magrtesium alloy in sulphate nickel bath is determined by orthogonal experiments. The results show that the coating deposited under the optimal process parameters is composed of Ni-P micro crystal, in which the content of P reaches 11.7wt. %. Its thickness reaches 20 μm after 2 h deposition. The coating is even and compact. The result of potentiodynamic polarization shows that the Ni-P coating has good corrosion resistance, which can provide good protection to the substrate.
出处
《表面技术》
EI
CAS
CSCD
2006年第5期40-42,59,共4页
Surface Technology
关键词
镁合金
化学镀镍
前处理
腐蚀
Magnesium alloy
Electroless nickel plating
Pretreatment
Corrosion
