对AM60镁合金轮毂材料进行了活化工艺研究,采用金相法、3.5%NaCl溶液浸泡试验、划格试验研究了AM60镁合金活化对电镀效果的影响.结果表明,三种活化工艺都是在去除镁合金基体表面的氧化膜和氢氧化膜后形成新的含微孔的保护性膜,控制浸锌和电镀的速度,得到质量更好的镀层.焦磷酸钾活化的效果最好,当K4P2O7·3H20的浓度为120~200g/L、Na2C03为10~30g/L、KF·2H2O为11g/L时,电镀镍层耐蚀性好,结合力强.
Activation of AM60 magnesium alloy is investigated. The surface morphology of the specimens is observed with metalloscope. The corrosion resistance and the adhesion of nickel platings are evaluated by dipping in 3.5% NaCl solution and scribe-grid test respectively. The results show that the proposed three activation processes show similar effect. Activation can remove the original oxide and hydroxide films and therewith form a new protective porous film on the substrates. With the fresh film the rates of zincifying and Ni-electroplating on AM60 alloy is easy controlled and thus the quality of the electroplated coatings is improved. The corrosion resistance and adhesion are both well when magnesium alloys are activated in potassium pyrophosphate activation solution composed of 120 -200 g/L KaP2O7·3H2O, 10-30 g/L NazCOs ,and 11 g/L KF · 2H2O.