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镁锂合金是未来理想的轻量化金属材料,但其耐蚀性差,因此在其表面制备具有一定防腐性能的涂层,对于其发展具有重要意义.本文总结了近年来关于镁锂合金表面防腐涂层的研究,重点介绍了几种镁锂合金表面防护技术,包括:化学镀与电镀、化学转化、阳极氧化、有机-无机转化、表面喷涂等,指出了目前镁锂合金表面防护技术存在的问题,并展望了镁锂... 相似文献
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氨基乙酸对镁-锂合金阳极氧化膜的影响 总被引:1,自引:1,他引:0
在镁-锂合金阳极氧化中以氨基乙酸为添加剂制取氧化膜,并讨论氨基乙酸对氧化膜结构、形貌及性能的影响.利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、无损涡流测厚仪、极化曲线(Tafel)和电化学交流阻抗谱(EIS)等分析了镁-锂合金基体和氧化膜的组成、表面形貌、厚度以及耐蚀性,并讨论其耐蚀机理.结果表明:阳极氧化膜主要由氧化镁、氢氧化镁和氢氧化锂构成;随着氨基乙酸的质量浓度的增加,阳极氧化膜趋于平整、致密,孔洞均匀;添加氨基乙酸形成的阳极氧化膜的自腐蚀电位正移,自腐蚀电流密度变小,当其质量浓度为6 g/L时,氧化膜耐蚀性最优,自腐蚀电流密度为1.12×10-7A/cm2;但当氨基乙酸的质量浓度过高时,氧化膜耐蚀性反而下降.电化学阻抗谱对氧化膜耐蚀性变化规律的分析与极化曲线结果相一致. 相似文献
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The adhesion of a plasma polymer and the corrosion protection offered to aluminum alloy substrates depends on the cleanliness of the substrate surface and the state of oxides on the aluminum alloy surface. Both factors are dependent on what type of alloy is used, and consequently, the best preparation of the substrate surface differs on the type of aluminum alloy. Oxygen plasma treatment is effective for the elimination of organic surface contamination, but plasma treatment, such as that of mixed argon and hydrogen, cannot be used to modify the surface state of oxides on these alloys. This is because oxides of aluminum are stable and thus resist plasma modification, and prolonged plasma treatment has been observed to change concentrations of alloy components at the surface due to the heating of the alloy. Chemical cleaning of the surface is necessary before the application of the plasma polymer used for corrosion protection enhancement. Once the surface was properly prepared, a plasma polymer of trimethylsilane (TMS), prepared by cathodic polymerization, adhered well to aluminum alloys investigated in this study. Major adhesive failure, however, occurred as a consequence of reactor contamination when hexafluoroethane (HFE) plasma treatment of initially formed TMS plasma polymers was employed. Plasma pretreatment of the substrate with O2 or postplasma treatment of the plasma polymer of TMS with Ar (instead of HFE) was effective in eliminating the surface‐contamination effect on the adhesion. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1387–1398, 2002 相似文献
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民用飞机钛合金紧固件表面处理的应用与研究 总被引:1,自引:0,他引:1
阐述了国内外民用飞机钛合金紧固件表面处理的现状与差异。分析了钛合金紧固件不同表面处理的作用与区别。研究了钛合金紧固件表面处理的验证方法。提出了钛合金紧固件表面处理今后的发展趋势。 相似文献
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Ju-mei Zhang Jia-cheng Li An-rong Hou Xin Duan Duo-duo Lian Meng-chun Zhang Teng Zhang 《International Journal of Applied Ceramic Technology》2022,19(6):3062-3071
Magnesia-alumina layered double hydroxide (Mg-Al LDH) films grown in situ on LA43M magnesium-lithium (Mg-Li) alloy were synthesized utilizing the hydrothermal method. Scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), and X-ray diffraction (XRD) were used to characterize the surface morphologies, composition, and phase of the Mg-Al films. The corrosion resistance of the Mg-Al films was estimated via immersion experiment and hydrogen evolution test, and the tribological properties were investigated using tribological wear tests. The results showed that the thickness of the Mg-Al LDH film enhanced, and the size of the LDH sheets increased as the hydrothermal temperature raised, resulting in the improvement of the corrosion and wear resistance. When the hydrothermal temperature reached 110°C, interlayer anions were loaded the most, and the film achieved the optimal thickness. The Mg-Al LDH film had the optimum corrosion resistance and tribological properties. At this point, the weight loss of the film was 1.3560 mg·cm–2, and the average friction coefficient was .149. It demonstrated that synthesizing Mg-Al LDH at a hydrothermal temperature of 110°C was an effective approach to improve the corrosion resistance of LA43M. 相似文献
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采用循环伏安法研究了锂电解过程中杂质元素的电化学行为。电解过程中杂质元素镁将优先于锂在阴极析出, 然后是金属锂的欠电位沉积形成镁锂合金, 最后才是金属锂的析出, Mg 2+的还原电极过程受扩散控制, 扩散系数为1.44×10 -5 cm 2/s;微量的Ca 2+即发生钙锂共沉积;在含少量氯化钠的熔盐体系中, 杂质元素钠被锂还原并形成合金, 随着电解质体系中氯化钠含量的增加, 金属锂中的钠含量有较大的增加;杂质元素铁优先于锂在阴极析出, 在阴极被还原成海绵铁使阴极钝化, 引起熔盐体系锂的析出电流急剧降低, Fe 3+的还原电极过程受扩散控制, 扩散系数为3.14×10 -5 cm 2/s。 相似文献
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化学转化膜是金属表面主要的处理方法之一,具备良好的附着力和耐蚀性,能为铝合金提供一定的临时防护。传统的六价铬酸盐化学转化膜在日渐严苛的环保压力下已经逐渐淘汰,取而代之的是近几年发展迅猛的三价铬及无铬锆基化学转化膜。铝合金可分为铸造铝合金和变形铝合金,按照所含主要合金元素和热处理状态可分为若干个系列和型号。本文选取几种典型的变形铝合金,综述了不同铝合金微观组织对转化膜成膜过程的影响,化学转化液添加剂、预处理和后处理工艺对转化膜性能的调控及作用机理,以及几种典型商业钝化剂在变形铝合金表面的应用。总结了目前变形铝合金表面锆基化学转化膜仍面临的问题和发展趋势,未来化学转化膜需在满足新型铝合金发展要求的基础上,通过不同有机、无机添加剂以及外场作用对转化膜的成膜均一性、完整性进行调控,以提高转化膜的综合性能。 相似文献
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用相反转法将含分散剂的水滴加到熔融的Bi-Pb-Sn-Cd易熔合金液中,制备了一系列超细合金粉,使超细粉的制备与表面修饰同步进行,系统研究了制备过程中温度、搅拌速度和分散剂浓度对超细合金粉粒径的影响。实验结果表明,随着水在合金液中含量的增加,体系发生相转变,合金从连续相逐渐破裂成分散相而形成超细金属粉,同时改性剂以物理吸附的方式对超细金属粉进行表面改性;制备温度、搅拌速度和分散剂浓度对合金粉粒径有明显影响,以浓度为1%的油酸钠为分散剂,温度为85℃,搅拌速度为1750r.min-1,可制得平均粒径为0.3μm的超细Bi-Pb-Sn-Cd合金粉。为获得满意粒径和表面改性效果的超细合金粉,必须将制备温度、搅拌速度和分散剂浓度控制在适当的范围。 相似文献
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