苯甲酸钠含量对硼酸-硫酸阳极氧化膜形貌和性能的影响

Effect of Sodium Benzoate Content in Boric Acid-Sulfuric Acid Electrolyte on Morphology and Corrosion Resistance of Anodizing Coating of Aluminum Substrate

为了探讨添加剂苯甲酸钠含量对2种2024铝合金阳极氧化膜质量的影响,添加了不同含量的苯甲酸钠于硼酸-硫酸电解液中在2024包铝和2024裸铝表面进行阳极氧化,通过对膜层膜重、结合力、耐蚀性、微观结构等的分析,确定了苯甲酸钠的最佳含量。结果表明:苯甲酸钠含量对2024裸铝和2024包铝硼酸-硫酸阳极氧化膜的膜重和2024包铝硼酸-硫酸阳极氧化膜的结合力没有影响;当苯甲酸钠含量小于等于1.00 g/L时,苯甲酸钠含量对2种2024铝合金硼酸-硫酸阳极氧化膜层的表面微观形貌没有影响;当苯甲酸钠含量较高(2.00g/L)时,2024裸铝上的硼酸-硫酸阳极氧化膜层表面孔洞数量有一定增加,但仍能耐336 h盐雾腐蚀。

Various contents of sodium benzoate additive were introduced in boric acid-sulfuric acid electrolyte to conduct anodizing of bare 2024 Al and cladding 2024 Al alloys. The effect of sodium benzoate content on the morphology and corrosion resistance of anodizing coatings of the two kinds of Al alloys was explored,and the optimal sodium benzoate content was determined in relation to mass,bonding strength, corrosion resistance,and microstructure of the anodizing coatings. Results indicated that the content of sodium benzoate had no influence on the mass of the anodizing coatings of the two kinds of Al alloys; and it also had no influences on the bonding strength of the anodizing coating of the cladding Al alloy. Besides,when the content of sodium benzoate was equal to or below 1. 00 g / L,it had no influence on the morphology of the anodizing coatings. Moreover,when the content of sodium benzoate was relatively high(2. 00 g / L),relevant anodizing coating on bare Al alloy had slightly increased amount of pores but retained almost unchanged corrosion resistance( being able to endure against 336 h of salt-spray).