共查询到19条相似文献,搜索用时 125 毫秒
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AZ91D镁合金磁控溅射镀铝膜及其化学转化后的耐蚀性 总被引:2,自引:0,他引:2
采用磁控溅射镀铝与化学转化复合处理的方法对AZ91D镁合金表面进行处理,制得复合处理膜层,并与单纯磁控溅射镀铝膜层的耐蚀性进行了比较。结果表明,磁控溅射所得铝膜层结构致密,铝膜层与镁合金基体界面形成混合过渡层。沉积铝膜后再进行阿洛丁化学转化所得膜层表面存在裂纹,化学转化膜与铝膜之间结合良好。磁控溅射铝膜层使镁合金的腐蚀速率加快。镀铝与化学转化复合处理所得膜层的腐蚀电流密度比镁合金基体低1个数量级以上,表明镀铝与化学转化复合处理可明显提高镁合金的耐蚀性。中性盐雾试验4h后,铝膜表面腐蚀严重;而复合处理膜层在试验24h后表面只出现少量的腐蚀,48h后只有5%的面积被腐蚀。 相似文献
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镁合金表面处理的研究现状与展望 总被引:1,自引:0,他引:1
综述了镁合金表面处理技术的工艺进展,主要包括化学转化膜、阳极氧化、微弧氧化、金属涂层、离子注入等技术。分析了镁合金表面处理研究的发展趋势。 相似文献
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采用划叉浸泡实验,电化学交流阻抗(electrochemical impedance spectroscopy,EIS),开路电位(open circuit potential,OCP)及动电位扫描研究了不同类型的环氧树脂对于AZ91D镁合金的表面的富镁涂层的保护性能的影响。结果表明环氧618-593构成的富镁涂层防护性能较差;环氧6101-TY650制备的富镁涂层可明显改善涂层对破损处镁合金基体的保护作用,但涂层本身长期防护性能较差;环氧618-T31构成的富镁涂层对AZ91D镁合金的防护作用较强,适宜制备镁合金表面的富镁涂层。3种环氧涂料中加入镁粉颗粒制备的富镁涂层均可对缺陷处裸露的AZ91D镁合金基体提供保护,从而延长漆膜的破坏时间。涂层中的镁粉颗粒被激活后,为镁合金的基体提供了一定程度的阴极保护作用,减缓了镁合金基体的腐蚀。 相似文献
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以磷酸盐-氟盐-高锰酸盐配制镁合金的活化溶液,实现了镁合金表面直接沉积镍-磷合金镀层。采用扫描电子显微镜、能谱仪和X-射线衍射仪研究了镁合金活化后的形貌和成分。结果表明,活化转化膜层致密,主要成分为MgF_2-Mg_3(PO_4)_2复合结构。极化曲线和结合力测试表明,转化膜可有效地防止镀液对镁基体的腐蚀,所得镍-磷合金镀层致密,具有良好耐蚀性能,且镀层和镁基体间的结合力良好。 相似文献
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Copper immersion coating of magnesium alloys has, to date, been conducted only in acidic baths. This article describes a novel
alkaline bath for copper immersion coating on AZ91D magnesium alloy. Prior to the coating process, a chemical etching process
of the magnesium substrate was optimized using orthogonal experimental methodology. The copper immersion coating was then
investigated with regard to the effect of pH and fluoride content in the deposition bath. It was revealed during the coating
process that an increase of pH and fluoride content led to a surface film formation on the magnesium substrate. The surface
film formation occurred simultaneously with copper reduction, rendering a controlled magnesium dissolution, thereby a controlled
copper deposition. With optimized conditions of chemical etching and immersion coating processes, uniform copper deposits
were achieved. 相似文献
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Iryna Kozina Halina Krawiec Maria Starowicz Magdalena Kawalec 《International journal of molecular sciences》2021,22(15)
Chitosan coatings are deposited on the surface of Mg20Zn magnesium alloy by means of the spin coating technique. Their structure was investigated using Fourier Transform Infrared Spectroscopy (FTIR) an X-ray photoelectron spectroscopy (XPS). The surface morphology of the magnesium alloy substrate and chitosan coatings was determined using Scanning Electron Microscope (FE-SEM) analysis. Corrosion tests (linear sweep voltamperometry and chronoamperometry) were performed on uncoated and coated magnesium alloy in the Hank’s solution. In both cases, the hydrogen evolution method was used to calculate the corrosion rate after 7-days immersion in the Hank’s solution at 37 °C. It was found that the corrosion rate is 3.2 mm/year and 1.2 mm/year for uncoated and coated substrates, respectively. High corrosion resistance of Mg20Zn alloy covered by multilayer coating (CaP coating + chitosan water glass) is caused by formation of CaSiO3 and Ca3(PO4)2 compounds on its surface. 相似文献
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Bing Wang Ping Huang Caiwen Ou Kaikai Li Biao Yan Wei Lu 《International journal of molecular sciences》2013,14(12):23614-23628
Magnesium and its alloys—a new class of degradable metallic biomaterials—are being increasingly investigated as a promising alternative for medical implant and device applications due to their advantageous mechanical and biological properties. However, the high corrosion rate in physiological environments prevents the clinical application of Mg-based materials. Therefore, the objective of this study was to develop a hydroxyapatite (HA) coating on ZK60 magnesium alloy substrates to mediate the rapid degradation of Mg while improving its cytocompatibility for orthopedic applications. A simple chemical conversion process was applied to prepare HA coating on ZK60 magnesium alloy. Surface morphology, elemental compositions, and crystal structures were characterized using scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction, respectively. The corrosion properties of samples were investigated by immersion test and electrochemical test. Murine fibroblast L-929 cells were harvested and cultured with coated and non-coated ZK60 samples to determine cytocompatibility. The degradation results suggested that the HA coatings decreased the degradation of ZK60 alloy. No significant deterioration in compression strength was observed for all the uncoated and coated samples after 2 and 4 weeks’ immersion in simulated body fluid (SBF). Cytotoxicity test indicated that the coatings, especially HA coating, improved cytocompatibility of ZK60 alloy for L929 cells. 相似文献
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High corrosion protection of a polyaniline/organophilic montmorillonite coating for magnesium alloys
Epoxy coatings containing polyaniline (PANI) and polyaniline/organophilic montmorillonite (PANI/OMMT) powders were prepared on the surface of AZ91D magnesium alloy. The corrosion performance of the coatings was evaluated by electrochemical impedance spectroscopy (EIS) and open-circuit potential analysis in 3.5% NaCl. The results indicate that the PANI/OMMT coating retained its high corrosion protection for AZ91D magnesium alloy after 6000 h of immersion. The protective mechanism conferred by the PANI/OMMT coating was also discussed. The effects of oxygen on the protective mechanism of PANI were evaluated by EIS measurements in a 3.5% deaerated NaCl solution. 相似文献
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A pretreatment with galvanostatic etching is recommended to obtain an adherent and uniformly covered copper deposit on pure magnesium and magnesium alloy specimens (AZ31 and AZ61) in an alkaline copper-sulfate bath. The effect of galvanostatic etching on the surfaces of Mg and Mg alloy specimens can be realized by their potential variation during galvanostatic etching, in which four distinct stages could be distinguished. Galvanostatic etching to stage III, an activated surface of Mg or Mg alloy, was obtained for electroplating a uniformly covered Cu deposit in the alkaline Cu-sulfate bath. The Cu-deposited Mg or Mg alloy was used as the substrate for further Cu and then Ni electrodeposition in acid plating baths to obtain a protective Ni/Cu coating. The proposed electroplating baths are environmentally friendly, and the electrodeposition process is easy to conduct to achieve a protective coating for Mg and Mg alloys. 相似文献