镁合金化学镀电镀复合镀层的制备

Preparation of Composite Deposit by Electroless and Electric Plating on Magnesium Alloy

镁合金具有高的比强度和比刚度、电磁屏蔽性、减震性等优点,广泛应用于航空航天、汽车、电子通讯等领域。然而,由于镁合金的化学活性较高,其耐蚀性能较差,限制了它们的应用。通过改进的镁合金加工工艺可以提高镁合金耐蚀性。另外1种提高镁合金耐蚀性的有效手段就是对镁合金进行表面处理,如化学转化膜、电镀等。这些处理得到的涂层耐蚀性虽然有了很大的提高,但是在长时间处于腐蚀环境中,也容易被腐蚀,因此,研究1种复合镀层来更进一步提高耐蚀性,可以提高镁合金的应用。通过采用以硫酸镍为主盐对镀层进行化学镀镍,在化学镀层基础上电镀锌镍合金,并对化学镀和电镀配方进行优化,得到的复合镀层硬度高、结构致密、光泽性好,在5%的NaC l溶液盐雾试验中,连续喷雾96h无任何腐蚀现象,耐蚀性得到显著的提高。

Magnesium alloys have high specific strength and specific stiffness, electromagnetic shielding, and the advantages of shock absorption, etc. , are widely used in aerospace, automotive, electronic communications and other fields. However, because of the chemical activity of magnesium alloy higher corrosion resistance than its poor, limiting their applications. Through improved processing of magnesium alloy can improve corrosion resistance of magnesium alloy. Another kind of effective to improve corrosion resistance of magnesium alloy is the means to carry out surface treatment of magnesium alloy,such as chemical conversion coating, electroplating, coating and so on. However, these deal with the coating to be patient while significant improve, but in a long time in a corrosive environment, but also easy to corrosion, so on a composite coating to further improve corrosion resistance, magnesium alloy can improve the using. In this article, through the use of nickel sulfate salt mainly conducted on the electroless nickel plating, chemical coating based on zincnickel alloy composite coatings. And electroless plating and electroplating formula to optimize have high hardness, compact structure,good luster, in 5% NaCl salt solution trials, continuous spray for 96h without any corrosion, corrosion resistance increases significantly.