AZ91D镁合金磷化工艺的研究

通过浸泡式磷化处理在AZ91D镁合金表面沉积一层致密、均匀、结合力好的磷化膜。采用单因素试验法,得到磷化液的最佳配方和工艺条件为:ZnO 2g/L,H_3PO_420g/L,NaF 1g/L,Na_2C_4H_4O_64g/L,NaNO_36g/L,柠檬酸0.25g/L,pH值3.0,磷化温度45℃,磷化时间20min。同时,确定添加剂为焦磷酸钠(TSPP),并且当其质量浓度为0.5g/L时,磷化膜的耐蚀性最好。

Study on Phosphate Process for AZ91D Magnesium Alloy

Through immersion treatment in phosphate solution,a phosphate film,which was dense,uniform and having good adhesion to the substrate,was deposited on the surface of AZ91D magnesium alloy.The optimal formula of phosphate solution and process conditions were determined by single factor experiment as follows:ZnO 2 g/L,H3PO320 g/L,NaF 1 g/L,Na2C4H4O6 4 g/L,NaNO3 6 g/L,citric acid 0.25 g/L,pH value 3.0,phosphating temperature 45 ℃,phosphating time 20 min.Furthermore,TSPP was determined as the additive,and the corrosion resistance of phosphate film was the best when the mass concentration of TSPP was 0.5 g/L.