前处理工艺对AZ91D镁合金直接化学镀镍的影响

Influence of pretreatment on AZ91D magnesium alloy by direct electroless nickel plating

研究AZ91D镁合金直接化学镀镍的前处理工艺。通过光学显微镜、扫描电镜及能谱仪等设备分析AZ91D镁合金经过各步前处理工艺后试样的表面形貌、表面成分及镀镍层的相组成;确定AZ91D镁合金直接化学镀镍的碱洗,酸洗以及活化工艺。试验结果表明,以CrO3 125 g/L,HNO3(68%)110 mL/L为酸洗液,NaCl 0.26 g/mL为活化液,在镁合金上直接化学镀镍,可以得到表面较平整、均匀,无明显缺陷的非晶态Ni-P合金镀层。

The pretreatment processes of direct electroless nickel plating on AZ91D magnesium alloy were studied in this paper.The surface morphology and surface composition after pretreatment processes,and the phase composition of nickel coating were analyzed by Optical Microscope,SEM and Energy Spectrometer and so on.And the alkali washing process,the pickling process and the activating process were defined.Results show that in the conditions of pickling in CrO3 125 g/L and HNO3（68%） 110 mL/L solution,and actvating in NaCl 0.26 g/mL solution,an amorphous nickel and phosphor plating layer with flat,uniform surface and no remarkable defects can be obtained.