镁合金件有机防护涂层的耐腐蚀性能研究

为提高镁合金的耐腐蚀性能,利用复合有机涂层技术在ZM5铸镁合金表面制得防腐涂层。研究了镁合金的前处理、有机防腐涂装以及装饰性涂装工艺条件及其涂膜性能。利用化学转化膜对镁合金进行表面处理,再用复合有机涂层提高镁合金的防腐性能。结果表明:该有机涂层体系对镁合金有较好的腐蚀防护作用,化学转化膜可以提高镁合金与有机涂层的结合力并提高其耐腐蚀性。     

镁合金表面处理的研究现状与展望

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。     

AZ91D镁合金磁控溅射镀铝膜及其化学转化后的耐蚀性

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。     

溶胶改善镁合金化学转化膜的研究进展

镁合金表面化学处理的方法包括:铬酸盐转化、磷酸盐转化、氟锆酸盐转化、锡酸盐转化、稀土转化等.处理后的转化膜存在孔隙,有微裂纹,需要进行封孔处理,可通过溶胶改善镁合金的转化膜.对涂覆后的化学转化膜进行热处理或采用微弧氧化处理,可以提高溶胶与膜层的结合力与耐蚀性.     

NaVO_3对AZ91D镁合金化学转化膜耐蚀性的影响

向镁合金植酸处理液中添加NaVO_3,研究了NaVO_3对镁合金化学转化膜耐蚀性的影响。结果表明:加入NaVO_3后,镁合金化学转化膜表面的裂纹有细化和减少的趋势,化学转化膜呈现明显的容抗特性,交流阻抗可达3 800Ω,自腐蚀电流密度明显减小,而且化学转化膜的耐中性盐雾时间达到42h。     

镁合金表面化学转化膜的研究现状

综述了镁合金化学转化膜如铬酸盐转化膜、磷酸盐转化膜、锰酸盐/高锰酸盐转化膜、锡酸盐转化膜、稀土转化膜、植酸转化膜的研究现状,分析了这些化学转化工艺存在的不足,并展望镁合金表面化学转化膜的发展趋势。     

镁合金表面化学转化膜处理溶液

镁合金在各种腐蚀介质中很容易腐蚀。通常用化学转化膜处理提高其耐蚀性,而传统的镁合金转化膜处理液都使用基于铬的各种化合物,工艺不环保。专利CN1236104C与专利CN1880503A分别公开了两种镁合金表面处理方法,其中公开了两种环保型表面处理溶液的配方,但用两种处理溶液形成的化学转化膜的附着力都不高,实验得出,     

镁合金ZM5“无铬”化学转化处理

采用含磷酸盐-高锰酸盐的"无铬"化学转化液处理方法,在镁合金ZM5表面形成了一层化学转化膜,用金相显微镜、腐蚀实验分别研究了化学转化膜层表面形貌、耐腐蚀性。结果表明,化学转化处理的最佳工艺条件为:KMnO4质量浓度20 g/L,Na3PO4质量浓度100 g/L,KF质量浓度40 g/L,转化液呈弱碱性,pH=7～8,温度50℃,化学转化时间40 min。在镁合金ZM5表面形成的化学转化膜耐腐蚀性能良好,对镁合金基体有较好的保护作用。     

镁合金表面自愈性化学转化膜的研究进展

介绍了镁合金表面具有自愈性的钒酸盐转化膜、锡酸盐转化膜、稀土转化膜、植酸转化膜和石墨烯转化膜的制备和性能特点,对现阶段镁合金表面无铬自愈性化学转化技术存在的问题进行了探讨,并展望了其未来发展的方向。     

镁合金无铬化学转化膜的研究进展

随着人们环保意识的提高,开发无毒无污染的镁合金无铬转化膜也越来越得到重视.较详细地综述了镁合金无铬化学转化膜的发展现状,主要介绍了磷酸盐转化膜、磷酸盐,高锰酸盐转化膜、锡酸盐转化膜、钼酸盐转化膜、稀土转化膜等工艺,对膜层的耐蚀性、耐磨性等进行了比较,提出镁合金无铬化学转化膜是今后研究的热点.     

Conversion coating treatment for AZ31 magnesium alloys by a phytic acid bath

A phytic acid chemical conversion bath was applied to a sample of AZ31 magnesium alloy in this study; a transparent conversion coating formed subsequently on the sample surface. The test results of this coating with a scanning electron microscope (SEM) showed that there exist compact coatings on the surface of treated magnesium alloy. With the analyses of electronic probe microscopy (EPMA) and IR spectrum, a further study of this coating indicated that the coating was mainly composed of phytate and oxide or hydroxid. Furthermore, The electrochemical tests showed that the phytic acid bath conversion treatment enhanced the corrosion resistance of AZ31 magnesium alloys. The optimal pH of the phytic acid bath was 9.00–10.00.     

Research progress of surface modification of biomedical magnesium

由于镁具有优异的生物相容性、可生物降解性及适宜的力学性能而成为潜在的生物医用材料。本文对镁作为生物材料的优缺点进行了综合的评价,分类综述了用不同的表面改性技术在镁及其合金表面制备不同的涂层,包括电化学沉积法及阴极沉积法、离子注入及离子电镀法、阳极氧化及微弧氧化法以及化学转化法,评述了这些涂层对镁的腐蚀性能与生物活性的影响,并对镁作为一种新型可降解的硬组织植入材料的应用前景进行了展望。     

镁合金表面自修复防护膜层的研究进展

对镁合金表面自修复防护膜层的研究进行了综述,通过介绍自修复膜层的作用机理、制备及性能特点,为设计镁合金表面自修复防护涂层提供参考。     

镁合金压铸件的性能及表面处理

介绍了国内外镁合金的应用现状及前景，综述了镁合金的组成，性能及阳极氧化和化学转化膜等表面处理。     

High corrosion resistance of electroless composite plating coatings on AZ91D magnesium alloys

The process of electroless plating Ni-P on AZ91D magnesium alloys was improved. The Ni-P-ZrO₂ composite coatings and multilayer coatings were investigated based on the new electroless plating process. The coatings surface and cross-section morphologies were observed with scanning electron microscopy (SEM). The chemical compositions were analyzed by EDXS. The corrosion behaviors were evaluated by immersion, salt spray and electrochemical tests. The experimental results indicated that the Ni-P-ZrO₂ composite coatings suffered attack in NaCl solution but displayed passivation characteristics in NaOH and Na₂SO₄ solutions. The corrosion resistance of Ni-P-ZrO₂ coatings was superior to Ni-P coatings due to the effect of ZrO₂ nano-particle. The multilayer coatings consisting of Ni-P-ZrO₂/electroplating nickel/Ni-P (from substrate to surface) can protect magnesium alloys from corroding more than 1000 h for the salt spray test.     

镁合金用抗静电耐温涂料研究

本文研制了一种镁合金用抗静电耐温涂料。通过对基料树脂、颜填料、和助剂的筛选与研究,研制了镁合金专用底漆和面漆配套体系,该底漆具有优异的附着力,与面漆配套具有良好的抗静电、耐温性、防腐性等综合性能。     

铝及其合金无铬钝化的研究进展

综述了国内外铝及其合金的无铬钝化体系的研究状况及其特点,为铝和铝合金无铬钝化的研究提供参考。并对铝及其合金无铬化学转化膜的研究方向提出展望。     

镁合金表面防护涂层的研究进展

镁合金以其高比强度、比模量和优异的力学性能,已在众多领域受到广泛关注。但是,化学活性高、耐蚀性能差的缺陷制约了其应用范围。寻找一种合适的表面处理方法已成为必然。本文概述了国内外关于镁合金表面防护涂层的研究现状,主要有化学转化膜、阳极氧化膜、金属涂(镀)层、激光表面合金改性层、气相沉积层和溶胶-凝胶涂层等。展望了镁合金表面防护涂层的发展趋势。     

Purely inorganic coatings based on nanoparticles for magnesium alloys

The chemical nanotechnology is offering a chance to apply stable inorganic coatings onto magnesium alloys. The cast alloy AZ91 as well as the wrought alloy AZ31 could be dip-coated with aqueous dispersions based on commercially available silica particles and various additives. The high surface activity of the nanoparticles and appropriate additives, e.g. boron, aluminium or alkali salts, help to densify these coatings under moderate conditions even suitable for those thermally precarious magnesium alloys.Another coating technique is based on the electrophoretic deposition of nanoparticles already containing all sintering aids. These particles could be synthesised by a base-catalysed sol-gel process. Polydiethoxysiloxane can act as an adhesion promoter for these coatings. Additionally concentration gradients of different oxides within these particles can adjust the coating properties, too.Usually single coatings are very thin (200-500 nm). However, multiple coating applications as well as a process involving special particle mixtures lead to coatings with a thickness of up to several micrometers. Even after thermal treatment at 200 or 400 °C these coatings stay crack-free. The composition and texture of these coatings were studied using IR, atomic force microscopy (AFM), scanning electron microscopy (SEM) and other techniques. Electrochemical impedance measurements show an improvement of the corrosion performance by these coatings. The coating resistance is improving with the coating thickness.