镁合金化学抛光工艺

Chemical polishing process of magnesium alloy

研究了一种应用于AZ31镁合金的化学抛光工艺。通过考察抛光液组成及工艺参数对镁合金失重和反射率的影响,确定了较佳的抛光工艺条件为:磷酸650mL/L,丙三醇250mL/L,柠檬酸0.6g/L,硫酸铜0.5g/L,温度50°C,时间3min。经此条件抛光后的镁合金表面平整光亮,失重为23g/cm2,反射率为50%,在3.5%(质量分数)NaCl溶液中的腐蚀电位比未抛光时正移0.9V,腐蚀电流密度下降近一个数量级,耐蚀性提高。

A chemical polishing process for AZ31 Mg alloy was studied. The effects of composition of polishing solution and process parameters on weight loss and reflectivity of the Mg alloy were discussed. The optimal polishing process conditions were obtained as follows： HaPO4 650 mL/L, glycerol 250 mL/L, citric acid 0.6 g/L, copper sulfate 0.5 g/L, temperature 50 ~C, and time 3 rain. The Mg alloy surface polished under the above conditions is level and bright, and has a weight loss of 23 g/cm2 and a reflectivity of 50%. The corrosion resistance of the Mg alloy is improved after polishing due to the positive shift of corrosion potential by 0.9 V and the decrease of corrosion current density by nearly one order of magnitude in 3.5wt% NaC1 solution as compared with the Mg alloy without polishing.