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添加剂铬酸钾对TC4钛合金微弧氧化膜层性能的影响 总被引:1,自引:0,他引:1
以TC4钛合金为基体,在硅酸钠电解液中进行微弧氧化(MAO)。电解液的主要成分为Na2SiO3、Na3PO4和NaOH,工艺条件为:电压450V,频率500Hz,占空比30%,时间5min。通过向电解液中添加0.5g/LK2CrO4对微弧氧化膜层进行着色。采用涡流测厚仪、维氏硬度计、扫描电镜、X射线荧光光谱分析仪以及中性盐雾试验等,研究了K2CrO4添加剂对膜层厚度、显微硬度和形貌等性能的影响。结果表明,所得微弧氧化膜层为典型的不规则多孔氧化物陶瓷膜层,显微硬度和耐蚀性明显优于基材。在电解液中加入K2CrO4后,MAO膜层由灰色转变为深黄色;K2CrO4使膜层粗糙度和孔径增大,与基体结合处的缺陷减少,结合力增强;膜层的脆性和内应力降低,耐蚀性增强。 相似文献
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不同电解质制备多孔阳极化Al2O3的形貌与间接诱导形成钙磷涂层能力 总被引:1,自引:0,他引:1
利用在Na3PO4液中的直流恒压阳极氧化法和H3PO4液中的恒流阳极氧化法对纯铝片进行阳极化处理。用扫描电子显微镜观察经阳极氧化样品的形貌结构,电子能谱测定诱导生成钙磷涂层的元素构成。结果表明:Na3PO4电解液中阳极化铝片发生过氧化行为形成过氧化膜;以稀H3PO4为电解液制得了孔径可达120~150nm的规整多孔阳极氧化铝(anodic aluminum oxide,AAO)膜。经多步预处理后.再在模拟体液中浸渍2.5d,过氧化AAO膜比规整多孔AAO膜显示出更为优异的诱导生成钙磷陶瓷涂层的能力。 相似文献
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电流密度对AZ31B镁合金阳极氧化及膜层性能的影响 总被引:2,自引:1,他引:1
采用KOH-Na2SiO3-Na2B4O7-Na2CO3环保型电解液体系,研究了电流密度对AZ 31B铁合金阳极氧化过程、氧化膜微观形貌、膜层厚度、氧化膜耐蚀性等的影响.结果表明:在恒电流阳极氧化过程中,根据电压-时间曲线,阳极氧化过程可分为电压快速升高阶段、电压缓慢升高阶段、电压相对稳定阶段.随着电流密度的增大,电压-时间曲线的斜率增大,电压明显增大,点火时间缩短,但对击穿电压影响不大;随着电流密度的增加,膜层致密性、厚度、耐蚀性都呈先增大后减小的趋势.当电流密度为1.5 A/dm2时,阳极氧化膜的致密性和耐蚀性最好. 相似文献
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镁-锂合金阳极氧化工艺的研究 总被引:1,自引:0,他引:1
采用阳极氧化技术提高镁一锂合金的耐蚀性.使用一种无铬环保型碱性电解液得到了有一定耐蚀性的白色氧化膜.用正交实验优选了电解液中三种组分的质量浓度;用扫描电镜分析了氧化膜表面形貌;用极化曲线研究了氧化膜的电化学腐蚀行为.结果表明:当电解液组成为NaOH 50 g/L,Na2SiO3·9H20 40 g/L,Na2B47·10H2O 30 g/L,Na3C6H5O7·2H2O 40g/L时,获得的阳极氧化膜的耐蚀性最好.EDS和XRD分析表明:氧化膜主要是由MgO,MgCO3两相组成. 相似文献
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在汽车用2024铝合金阳极氧化使用的电解液中添加硫酸镧,并研究了硫酸锢的质量浓度对阳极氧化膜的厚度、膜重、硬度、表面形貌及耐蚀性的影响。结果表明:硫酸镧的催化作用有利于提高氧化速率,减小多孔层的孔径,从而提高阳极氧化膜的硬度及耐蚀性。当硫酸镧的质量浓度为0.8 g/L时,阳极氧化膜具有最高的硬度和最佳的耐蚀性。但当硫酸镧的质量浓度大于0.8 g/L时,稀土的吸附作用会使阳极氧化膜的性能有所降低。 相似文献
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为比较在高压阳极氧化条件下不同电解液体系中碱性含氧酸盐对6063铝合阳极氧化膜层厚度及氧化时间的影响,将6063铝合金置于Na2SiO3、Na2HPO4和NaAlO2三种电解液体系中制备出阳极氧化膜。用涡流测厚仪测试了膜层厚度,通过点滴腐蚀实验评价了Na2SiO3体系所得氧化膜的耐腐蚀性能,利用扫描电子显微镜(SEM)观察分析了氧化膜的表面形貌。结果表明,钨酸钠能显著提高膜层厚度和膜层的耐腐蚀性能,六偏磷酸钠(SHMP)能延长氧化时间,提高膜层的硬度;在硅酸盐体系中钨酸钠和六偏磷酸钠按1∶1的比例加入,能得到致密的高耐蚀性阳极氧化膜层。 相似文献
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对汽车用2024铝合金板材进行酒石酸阳极氧化处理,并研究了阳极氧化对铝合金的成分、结构、表面形貌及耐蚀性的影响。研究发现,铝合金阳极氧化膜是由表面多孔层和内部无孔层构成的。铝合金阳极氧化过程是一个氧化铝生成和溶解的动态过程。阳极氧化膜由刚玉结构的α-Al_2O_3和八面结构的γ-Al_2O_3构成,α相和γ相大大提高了阳极氧化膜的硬度和耐蚀性。阳极氧化膜为典型的多孔结构,孔洞分布均匀,孔径为50nm左右。 相似文献
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以磷酸钠为电解液,采用微弧氧化技术制备钛基TiO2膜,以该膜为阳极,钛片为阴极与40 W紫外灯和稳压电源组成电助光催化体系,以大红染料模拟废水来评价TiO2膜光电催化能力。研究了酸度和亚铁离子质量浓度等因素对光催化的影响。结果表明:光电催化提高了TiO2膜阳极的降解率;阴极槽内亚铁离子存在会形成电-芬顿体系,有助于提高光电催化降解率。当电解液中支持电解质硫酸钠浓度为0.5 mol/L、pH=3时阳极槽的降解率达到38%,阴极槽亚铁离子质量浓度为3.0mg/L时降解率达到68%。 相似文献
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TiO2 or SiO2 nanoparticles dispersed in an acetone solvent containing iodine were deposited on Mg-Al-Zn alloy by electrophoretic deposition (EPD). Subsequently, the composite oxide films were formed on the substrate by anodization in KOH-Na2SiO3 aqueous solutions containing TiO2 or SiO2 nanoparticles. The films formed by EPD were improved binding with the substrate by anodization under high voltages with sparking, and then the anodic films consisted of Si-Mg or Ti-Si-Mg composite oxides. The film thicknesses of TiO2 and SiO2 on the alloy increased with anodization time. In polarization tests, the films anodized under high voltages with sparking in the alkaline solutions had high corrosion resistance. Thus, the composite oxide films formed in the present method were successful in providing corrosion resistance to Mg alloy. 相似文献
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P. G. Russell 《Journal of Applied Electrochemistry》1986,16(1):147-155
The activity of anodic oxide films on nickel, iron and copper metal anodes in cryolite-alumina melts was calculated using values of the reversible potential obtained from a polarization scan of the corresponding metal electrode. The best results were obtained with prepolarized electrodes. The anodic oxide layer formed on nickel becomes thick and dense and remains adherent during the period of prepolarization. Similar activity calculations were made for selected nickel-, iron- and copper-cermet compositions containing either a MnZn ferrite or a nickel ferrite ceramic phase. Large activities were observed for a NiO type corrosion product on both the nickel and nickelcermet electrodes. The results suggest that a dense surface layer containing a NiO phase is formed on nickel-cermet electrodes. This layer may help lower corrosion by minimizing electrolyte penetration of the anode surface. 相似文献
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Maysam Mohammadi Ali Yazdani Mohammad E. Bahrololoom Akram Alfantazi 《Journal of Coatings Technology and Research》2013,10(2):219-229
In this article, the effects of two inorganic corrosion inhibitors, permanganate and phosphate anions, on morphology, composition, thickness, and corrosion resistance of the anodic film formed on 2024 aluminum alloy in sulfuric acid were investigated. Surface morphology of the oxide films were studied by field emission scanning electron microscopy. Electrochemical impedance spectroscopy and potentiodynamic polarization tests were conducted to assess the corrosion resistance of the coatings. These analyses showed that the presence of the mentioned inhibitors changed the coating morphology, especially in the case of phosphate ions. Corrosion results indicated that using inhibitors during the anodizing process increased the corrosion resistance of the anodized samples. The increases were approximately 81% and 97% for 0.05 M of permanganate and phosphate ions, respectively, compared with the anodized coatings in the absence of additives. An increase in the inhibitor concentration results in better corrosion resistance of the aluminum anodic layer. 相似文献
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钛合金材料在飞机发动机上的应用越来越广泛,为提高其使用的安全性和可靠性,解决采用硝酸/氢氟酸方法时存在的判别缺陷种类少、不清晰、易造成误判等技术难题,采用重量损失法和观察不同条件下氧化膜表面形貌的方法研究了蓝色阳极氧化溶液浓度、pH值、电压等参数对氧化膜层质量的影响,确定了蓝色阳极氧化溶液浓度及工艺参数(Na3PO4·12H2O 100~125 g/L、pH8~9、电压30±1 V),优选了钛合金活化溶液的配方(HNO342.8%~66.6%,HF 4.5%~7.5%)。研究结果表明,通过最终确定的活化溶液、阳极氧化溶液和工艺条件,可以获得色调鲜明,均匀的浅蓝色至蓝灰色背景的氧化膜,缺陷与背景颜色之间能够形成最大的对比度,便于零件表面缺陷的检查。 相似文献