材料期刊网

目的 提高镁合金表面的耐腐蚀和耐磨损性能.方法 采用非平衡磁控溅射离子镀技术与化学镀技术相结合,在GW83镁合金表面制备Ni+C复合膜层.通过扫描电子显微镜和拉曼光谱分析了薄膜的形貌、成分和结构.利用电化学和浸泡后ICP-AES测试,评价了该复合碳膜涂层的耐腐蚀性能.同时采用摩擦磨损试验获得Ni+C复合膜层的磨损寿命.结果 Ni+C复合膜层致密均匀,表面孔隙率极低,表面碳层为典型的类石墨膜并且含有大量的无序结构.相对于GW83镁合金来说,Ni+C复合膜层的存在导致在3.5％NaC1溶液中的腐蚀电位正移了301 mV,腐蚀电流密度从186 μA/cm2降低至11 μA/cm2.浸渍后ICP-AES试验显示,Ni+C涂覆的镁合金GW83的金属离子释放量更低.摩擦磨损试验表明,Ni+C涂层的磨损寿命为7000 s,与镁合金基体相比,Ni+C复合涂层极大地提高了其磨损寿命.结论 在该Ni+C复合膜层中,表面碳层较致密,与Ni层结合良好,显著提高了基体的耐腐蚀性能.此外由于存在较厚的Ni中间层,对膜层起到了较大的支撑作用,Ni+C复合膜层从而延长了基体镁合金的磨损寿命.

The work aims to improve corrosion and wear resistance of organic coating on magnesium alloys.Ni+C composite film was first prepared on the surface of GW83 magnesium alloy by combining unbalanced magnetron sputtering ion plating and chemical plating.The surface morphology and composition and structure of the coating were analyzed by using SEM observation and Raman spectrometer.Corrosion resistance of the composite carbon film coating was evaluated by performing electrochemical tests and post-dipping inductively coupled plasma atomic emission spectrometry (ICP-AES) measurement.Meanwhile,wear longevity of the Ni+C composite coating was obtained by performing friction-wear test.The Ni+C composite coating featured in dense and uniform coating,extremely low surface porosity and surface carbon layer of graphite-like film containing numerous disordered structures.Compared with GW83 magnesium alloy,since the Ni+C composite coating was present,corrosion potential (Ecorr) in 3.5wt％ NaC1 solution improved by 301 mV,while the corrosion current density decreased from 186 μA/cm2 to 11 μA/cm2.The post dipping ICP-AES test revealed that the Ni+C coated magnesium alloy GW83 featured in less metal ion release.The friction-wear test showed that wear longevity of Ni+C composite coating was 7000 s,and thus the wear longevity was prolonged remarkably compared with the substrate of magnesium alloy.Corrosion resistance of the magnesium alloy can be greatly improved by Ni+C coating due to the thick nickel interlayer and dense surface carbon layer in the Ni+C composite coating.Furthermore,wear longevity of the magnesium alloy substrate can be effectively prolonged by coating Ni+C comoosite as a result of mechanical support by the thick Ni interlayer.