植酸封孔对铝制件阳极氧化膜耐蚀性的影响

Effect of Phytic Acid Sealing on Corrosion Resistance of Anodic Oxidation Film on Aluminum Parts

首先对铝制件进行阳极氧化,然后使用植酸进行封孔。研究了溶液温度和封孔时间对铝制件阳极氧化膜耐蚀性的影响,结果表明:随着溶液温度从50℃升至90℃,封孔后阳极氧化膜的电荷转移电阻从1.61×10^(4)Ω·cm^(2)提高到3.25×10^(4)Ω·cm^(2),高频阻抗模值从2.42×10^(4)Ω·cm^(2)增大到5.16×10^(4)Ω·cm^(2),耐蚀性逐步提高。随着封孔时间从4 min延长至24 min,封孔后阳极氧化膜的电荷转移电阻先提高后降低,高频阻抗模值先增大后减小。植酸封孔最佳的溶液温度为90℃,封孔时间为18 min。封孔后阳极氧化膜的元素组成与未封孔阳极氧化膜相同,但形貌明显不同。与未封孔阳极氧化膜相比,封孔后阳极氧化膜具有良好的腐蚀耐久性,能为铝制件提供较长久的防护。

The aluminum part was anodized and then sealed with phytic acid,and the effect of solution temperature and sealing time on the corrosion resistance of anodic oxidation film was studied.The results showed that as the solution temperature rised from 50℃to 90℃,the charge transfer resistance of the sealed anodic oxidation film increased from 1.61×10^(4)Ω·cm^(2) to 3.25×10^(4)Ω·cm^(2),and the high-frequency impedance modulus value increased from 2.42×10^(4)Ω·cm^(2) to 5.16×10^(4)Ω·cm^(2),indicating that the corrosion resistance of sealed anodic oxidation film was gradually improved.As the sealing time extended from 4 min to 24 min,the charge transfer resistance and high-frequency impedance modulus of the sealed anodic oxidation film both increased first and then decreased.The optimal solution temperature for phytic acid sealing was 90℃,and the sealing time was 18 min.The element composition of the sealed anodic oxidation film was the same as that of the unsealed anodic oxidation film,but the morphology was obviously different.Compared with the unsealed anodic oxidation film,the sealed anodic oxidation film has better corrosion durability and can provide longer protection for aluminum parts.