6063铝合金碱性化学镀镍耐腐蚀性能研究

Investigation of the corrosion resistance of alkaline electroless nickel plating on aluminum alloy

针对6063铝合金不耐碱腐蚀的问题,对其表面进行了碱性化学镀镍处理以提高其在碱性溶液中的耐腐蚀性能。采用扫描电镜(SEM)、能谱分析仪(EDS)和X射线衍射仪(XRD)分别分析了镀镍层的表面微观形貌、成分和物相结构;采用电化学和全浸蚀腐蚀试验方法测试了铝合金化学镀镍前后在w(NaOH)=4%的NaOH溶液阳极极化曲线和腐蚀失重。研究结果表明,铝合金化学镀镍处理后其表面获得了致密的非晶态高磷镀镍层,化学镀镍后的铝合金阳极极化电位达到析氧过电位时,镀层依然没有破坏,并且该镀层在w(NaOH)=4%的NaOH溶液中基本不发生腐蚀。

Electroless nickel plating on the aluminum alloy in an Alkaline plating bath was investigated. The morphology, the phosphorus content and microstructure of the electroless nickel coatings obtained were studied by SEM, EDS, XRD and the corrosion resistance of that were studied by electrokinetic polarization curve and erosion corrosion in w（NaOH） = 4% NaOH solution. Results show that electroless nickel films are homogeneous and compact, high phosphorus content and non-crystalline coatings. The films effectively improve corrosion resistance of aluminum alloy in w（NaOH） = 4% NaOH solution.