纯镁表面NaMgF_3膜层的制备及其耐腐蚀性能  

Preparation and Corrosion Resistance of NaMgF_3 Film on the Surface of Pure Magnesium

作　　者：王勇[1,2] 李旭 乔丽英[1,2] 陈毅 WANG Yong;LI Xu;QIAO Liying;CHEN Yi(College of Material Science and Engineering,Chongqing University,Chongqing 400044;National Engineering Research Centre for Magnesium Alloys,Chongqing 400044)

机构地区：[1]重庆大学材料科学与工程学院,重庆400044 [2]国家镁合金材料工程技术研究中心,重庆400044

出　　处：《材料导报》2018年第22期3925-3930,3947,共7页Materials Reports

基　　金：重庆市应用开发计划项目(cstc2014yykfC50002);重庆市技术创新与应用示范项目(cstc2018jscx-msybX0090);中央高校基本科研业务费(2018CDJDCL0019)

摘　　要：采用4%(质量分数)NaF+冰醋酸溶液常温浸泡的方法,在纯镁表面制备氟化膜层来提高纯镁的耐腐蚀性。研究了冰醋酸浓度和浸泡时间对膜层质量的影响,利用SEM、XRD和EDS等分析了氟化膜层的形貌和结构,采用电化学实验、体外浸泡实验等研究了改性前后纯镁在模拟体液(SBF)中的耐腐蚀性能。结果表明:当冰醋酸浓度为5%(体积分数)、处理时间为8h时,可以得到致密、均匀的NaMgF_3膜层,该膜层由约0.3μm粒径的颗粒构成。NaMgF_3膜层使纯镁的腐蚀电位提高了740mV,腐蚀电流密度降低了两个数量级,浸泡过程中的腐蚀产物层更加平整。Surface modification is an effective method to improve the corrosion resistance of pure magnesium and its alloys. In this paper, a NaMgF 3 film was formed on pure magnesium surface by immersing the substrate in the solution with 4wt% NaF and different amounts of glacial acetic acid solution in distilled water at room temperature. The effect of glacial acetic acid concentration and immersion time on the film quality was studied. Scanning electron microscope （SEM）, X-ray diffraction （XRD） and energy dispersive spectrometer （EDS） were used to analyses the morphology and crystal structure of the film. The corrosion resistance of pure magnesium before and after surface modification was investigated by electrochemical tests and immersion experiments in simulated body fluid （SBF）. The optimal acetic acid concentration and immersion time were found to be 5vol% and 8 h, respectively. The NaMgF 3 film was compact and uniform, composed of cubic particles with the size of about 0.3 μm. As compared with the substrate, the corrosion potential of coated magnesium was increased by 740 mV, and the corrosion current density reduced by 2 orders of magnitude. Also, a smoother corrosion product layer formed in SBF.

关 键 词：镁 膜层 腐蚀 氟化 生物材料 

分 类 号：TG146[一般工业技术—材料科学与工程]