磷含量对AZ31镁合金化学镀Ni-P层结构和耐蚀性能的影响  

Effect of Phosphorus Contents on Structure and Properties of Electroless Ni-P Plating on AZ31 Magnesium Alloy

作　　者：袁亮[1] 马立群[1] 秦铁男[1] 丁毅[1] 

机构地区：[1]南京工业大学材料科学与工程学院,南京210009

出　　处：《腐蚀与防护》2010年第9期696-699,共4页Corrosion & Protection

摘　　要：采用化学镀法,通过改变还原剂与络合剂的浓度比以及镀液的pH值,可以控制AZ31镁合金基体上所得Ni-P镀层中的磷含量在较大范围内变化,从而获得不同性能要求的镀层。采用金相显微镜、扫描电镜(SEM)、能谱分析仪(EDS)、X射线衍射(XRD)及电化学极化等方法,分析了磷含量对Ni-P镀层微观形貌、物相结构和耐蚀性的影响。结果表明,高磷Ni-P镀层的球状颗粒细小致密,镀层与基体间的结合平整均一;随着磷含量的升高,镀层结构由晶态向非晶态转变;电化学结果表明,高磷Ni-P镀层具有更好的耐中性NaCl溶液点蚀性能。The phosphorus content of Ni-P coatings could be controlled by changing the pH value and concentrations of reducing agent and complexing agent, and the different performance coatings could be obtained. Effects of phosphorus content on the morphology, chemical composition, phase structure and corrosion resistance of the electroless Ni-P plating coatings were studied by methods of optical microscopy, SEM, El）S, XRD and electrochemical polarization. The results showed that the cellular microstructure of high phosphorus coatings was small and compact. The bonding area of coating and substrate was uniform. The structure of the coatings ehanqged from amorphous plus crystalline to amorphous with the increase of phosphorus content. Electrochemical results indicated that the coatings with high phosphorus content had more excellent pitting corrosion resistanee in NaCl solution.

关 键 词：磷含量 AZ31镁合金 化学镀镍 点蚀 

分 类 号：TG174.44[金属学及工艺—金属表面处理]