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对汽车用ZL101A铝合金进行阳极氧化,并分别采用热水封闭、钴盐封闭、锆盐封闭和铈盐封闭等无铬封闭工艺对阳极氧化膜进行封闭处理.表征了封闭前后阳极氧化膜的形貌,并测试分析了封闭前后阳极氧化膜的厚度和耐蚀性能.结果表明:与未封闭阳极氧化膜相比,封闭处理后阳极氧化膜的孔隙率降低,表面平整度和致密性改善,耐蚀性能有不同程度提... 相似文献
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选取在建筑领域常用的6463铝合金作为研究对象,为使其耐蚀性能得到显著提高,进行酒石酸阳极氧化然后采用镍盐封闭,同时进行硫酸阳极氧化及镍盐封闭作为对比.表征和测试了酒石酸氧化膜、硫酸氧化膜的显微形貌、成分和耐蚀性能,并研究了封闭对酒石酸氧化膜和硫酸氧化膜的影响.结果表明,Ni元素通过封闭被引入氧化膜中,封闭后硫酸氧化膜... 相似文献
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为提高建筑用6463铝合金的耐蚀性能,在6463铝合金表面制备酒石酸氧化膜,然后进行热水-镍盐双重封闭.研究了双重封闭对酒石酸氧化膜的形貌、厚度及耐蚀性能的影响,并与单一热水封闭、镍盐封闭作比较.结果表明:单一封闭和双重封闭对酒石酸氧化膜的厚度基本没有影响,但封闭前后酒石酸氧化膜的形貌、成分及耐蚀性能存在差异.双重封闭... 相似文献
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在铝合金表面制备阳极氧化膜,并采用环保型沸水封闭与稀土盐封闭方法相结合对阳极氧化膜进行双重封闭。研究了双重封闭后阳极氧化膜的微观形貌、厚度、硬度、弹性恢复能力和摩擦性能,并与未封闭阳极氧化膜和单一封闭后阳极氧化膜比较。结果表明:单一封闭和双重封闭对阳极氧化膜的厚度影响较小,但封闭前后微观形貌明显不同。与未封闭阳极氧化膜相比,双重封闭阳极氧化膜的硬度提高了约 26%,达到 347.5 HV,弹性模量提高了约27.8%,达到 52.068 GPa,摩擦因数和磨损失重仅为 0.37、2.08 mg/mm2。主要原因在于为双重封闭过程中发生多个反应,反应产物较好的封堵孔洞,更大程度改善阳极氧化膜的致密性,使其承载能力和抗塑性变形能力增强,从而表现出良好的力学性能。 相似文献
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对汽车用2024铝合金进行了硫酸阳极氧化处理,并使用硫酸镍结合铬酸钾的双重封闭技术对阳极氧化膜进行了封闭处理。结果表明:在2024铝合金表面制备的阳极氧化膜属于典型的多孔膜。经过硫酸镍一次封闭处理后,大量镍的氢氧化物填充于膜孔内,有效地降低了阳极氧化膜的自腐蚀电流密度。经过铬酸钾二次封闭处理后,铬酸镍进一步覆盖在膜孔表面,大大提高了阳极氧化膜的均匀性和致密性。经过双重封闭处理后,阳极氧化膜的阻抗明显增大,耐蚀性大大提高。 相似文献
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概述铝制品大多数都经过阳极氧化处理。氧化膜的防护性能主要取决于膜厚和封闭质量,或者说,其防护性能是膜厚和封闭质量的函数,因此,封闭是阳极氧化的一个重要环节。封闭质量的好坏,在很大程度上直接影响氧化膜的耐腐蚀性能。所以国际标准ISO 7599规定,对于铝阳极氧化膜,无论声明与否,封闭是永远必须的。西德标准 DIN 17611、DIN 相似文献
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选用Ti-6Al-4V钛合金作为基体在环保型电解液中制备阳极氧化膜,然后分别浸没在沸水、氟锆酸铵溶液、乙酸钙溶液中对阳极氧化膜进行封闭处理。采用扫描电镜、能谱仪和X射线衍射仪表征和分析未封闭及封闭处理后阳极氧化膜的微观形貌、化学成分与物相结构,并配制酸性氯化钠溶液作为腐蚀介质,研究未封闭及封闭处理后阳极氧化膜的耐腐蚀性能。结果表明:与未封闭阳极氧化膜相比,在沸水、氟锆酸铵溶液、乙酸钙溶液中封闭处理后阳极氧化膜中微孔数量减少,化学成分发生变化,耐腐蚀性能进一步提高,但封闭处理未影响阳极氧化膜的物相结构。在乙酸钙溶液中封闭过程中发生化学反应,生成水合二氧化钛、氢氧化钛、氢氧化钙和钛酸钙等多种产物,达到协同封闭效果,赋予封闭处理后阳极氧化膜良好的表面致密性,其耐腐蚀性能好于在沸水、氟锆酸铵溶液中封闭处理后阳极氧化膜,对钛合金的防护作用更强。 相似文献
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镁合金AZ61碱性阳极氧化工艺研究 总被引:1,自引:0,他引:1
文章用正交试验对镁合金AZ61的碱性阳极氧化工艺进行了优化研究,对优化条件下得到的氧化膜进行了耐蚀性能和物相分析。封孔氧化膜的主要成分是Mg(OH)2、MgSiO3、Mg0.36Al2.44O4,能够在镁合金表面形成致密膜,膜厚可达30μm,且实行封孔阻塞了腐蚀介质到达基体的通路,从而能保证氧化膜具有较强的防腐蚀性。 相似文献
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Sealing effects of anodic oxide films formed on Mg-Al alloys 总被引:1,自引:0,他引:1
Mg alloys were anodized in alkaline NaOH solutions with various additives as a non-chromate method. Specimen AZ91 was anodized
at a potential that produced a strong surface dissolution reaction and generated a large amount of Mg(OH)2. The effect of sealing after anodizing was investigated, focusing on the effects of sealing time, temperature and solution
conditions. The current density decreased with increasing A1(OH)3 concentration in 1 M NaOH solution during anodizing; sparking occurred at potentials above 80 V. The best corrosion resistance
with anodizing in 1 M NaOH solution occurred at a potential of 4 V, which caused the strongest active dissolution reaction.
The sealing effect improved with increasing time and temperature, and corrosion resistance was proportional to the relative
ratio of Mg(OH)2. If the oxygen thickness observed by EDX equaled the film thickness, the film formed at 4 V in 1 M NaOH was 10–15 Μm thickness.
The optimum corrosion resistance in sealing at various solutions after anodizing was 1M-NaOH solution. 相似文献
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The effects induced by a magnetic field on the oxide film growth on aluminum in sulfuric, oxalic, phosphoric and sulfamic acid, and on current transients during re-anodizing of porous alumina films in the barrier-type electrolyte, were studied. Aluminum films of 100 nm thickness were prepared by thermal evaporation on Si wafer substrates. We could show that the duration of the anodizing process increased by 33% during anodizing in sulfuric acid when a magnetic field was applied (0.7 T), compared to the process without a magnetic field. Interestingly, such a magnetic field effect was not found during anodizing in oxalic and sulfamic acid. The pore intervals were decreased by ca. 17% in oxalic acid. These findings were attributed to variations in electronic properties of the anodic oxide films formed in various electrolytes and interpreted on the basis of the influence of trapped electrons on the mobility of ions migrating during the film growth. The spin dependent tunneling of electrons into the surface layer of the oxide under the magnetic field could be responsible for the shifts of the current transients to lower potentials during re-anodizing of heat-treated oxalic and phosphoric acid alumina films. 相似文献
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稀土元素在铝合金阳极氧化后处理中的应用 总被引:7,自引:0,他引:7
研究了将稀土盐(如铈盐)用于铝合金阳极氧化后处理,测量了氧化膜在酸、碱介质中的耐蚀性。结果表明,经铈盐处理后,铝氧化膜的耐酸性明显提高,优于常温封闭处理,耐碱性却降低。这可能是由于氧化膜孔中的稀土化合物在碱性介质中优先溶解。 相似文献
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Metallic-monolith catalyst support with self-growing porous anodic alumina(PAA) film was prepared by anodizing Al plate. The effect of hydrothermal treatment(HTT) on the crystalline state and textural properties of PAA film was investigated by XRD, BET, SEM and TG. The HTT treatment above 50 °C and the subsequent calcination above 300 °C could convert the amorphous skeleton alumina into γ-alumina and increase the specific surface area(SBET). However, SEM images showed the HTT modification was a non-uniform process along the thickness of PAA film. The promotion effect of HTT on SBETwas non-linear, and the slope of SBETgradually decreased with the HTT temperature or time increased. The limited HTT effect should be attributed to a changed pore structure caused by an unfavorable pore sealing limitation. Pore widening treatment(PWT) before HTT could break the pore sealing limitation, because of the reduced internal diffusion resistance of hydrothermal reaction. The synergistic combination of PWT and HTT developed a PAA support with a large SBETcomparable to commercial γ-alumina. In the catalytic combustion of toluene, the Pt-based catalyst prepared by using the PWT and HTT comodified PAA support gave higher Pt dispersion and more favorable catalytic activity than that treated by HTT alone. The presence of a bimodal pore structure was suggested to be a decisive reason. 相似文献
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聚乙烯薄膜经过电晕处理后,热封温度提高,热封强度降低。这可通过降低电晕处理强度,适当延长热封时间和添加一定比例的mLLDPE树脂,以减小电晕处理对聚乙烯薄膜热封性能的影响。 相似文献