AZ91HP镁合金化学镀镍-磷前预处理工艺的研究

Study on Pretreatment Process of AZ91HP Magnesium Alloy Before Electroless Ni-P Plating

研究了采用H3PO4+Na2MoO4、H3PO4+KMnO4和H3PO4+Na3PO4三种溶液酸洗和用NH4HF2活化等预处理工艺对AZ91HP镁合金化学镀镍-磷的影响。结果表明,AZ91HP镁合金经H3PO4+Na3PO4溶液酸洗后再经NH4HF2活化处理,可获得光亮、与基体结合力强和耐蚀性能较好的镍-磷镀层。该镁合金酸洗处理后表面的平整程度可能影响其化学镀镀层的平整度和光亮度,而活化处理后的表面粗糙度则影响镀层与基体的结合力。

The effect of pretreatments consisting of pickling in H3PO4 plus Na2MoO4, H3PO4 plus KMnQ or HaPO4 ＋ Na3PO4 solution and activating in NH4HF2 solution was investigated on the electroless Ni-P plating of AZ91HP magnesium alloy. The experimental results are as follows： （a） both the pickling in H3PO4 plus Na3PO4 solution and activating in NH4 HF2 solution can allow AZ91 HP magnesium alloy to develop Ni-P plating which is bright, and able to adhere strongly to the substrate and to resist well corrosion; （b） the main factors affecting the smoothness and brightness of the electroless plating of the magnesium alloy are the surface roughness after pickling treatment, while the factor affecting the adhesion between the plating and the substrate is the surface roughness after the activating treatment.