工业纯钛TA2的阳极氧化工艺研究

通过对以C6H11O7Na,Na3PO4两种成分为电解液所形成的阳极氧化膜性能的比较,选用Na3PO4为主要成分的电解液。采用正交实验着重分析了Na3PO4的质量浓度、电压及氧化时间对在工业纯钛TA2上所形成的阳极氧化膜的显微硬度和耐蚀性的影响。结果表明:随Na3PO4的质量浓度的增大,其硬度和耐蚀性都呈增大趋势。综合阳极氧化膜的成膜速率和颜色的均匀性,得出工业纯钛TA2阳极氧化的最佳工艺条件为:Na3PO4200 g/L,电压20 V,氧化时间20 min。     

铝合金阳极氧化膜耐蚀性的研究

在硫酸电解液中,采用直流电源对铝合金进行阳极氧化处理。通过电化学测试和点滴实验,探讨了硫酸的质量浓度和氧化时间对阳极氧化膜耐蚀性的影响。结果表明:随着硫酸质量浓度的增加和氧化时间的延长,阳极氧化膜的耐蚀性有所提高;当硫酸的质量浓度为60g/L,氧化时间为30min时,阳极氧化膜的耐蚀性最好。     

钛的直流阳极氧化工艺研究

采用正交试验研究了工业纯钛板在碱性环保型溶液中阳极氧化工艺,确定了最佳工艺是温度为25℃,阳极氧化电流密度为120 mA/cm2,N aOH 70 g/L,N aA lO215 g/L,氧化时间为60 m in。测试结果表明:钛氧化膜为白色、多孔状的陶瓷膜层,膜层主要成分为T iO2,氧化膜的显微硬度远高于基体硬度;氧化膜的耐蚀性明显高于钛基体,可以达到生物医用材料的要求。     

铝合金阳极氧化膜性能的研究

研究了2 024铝合金在硫酸溶液中经不同氧化电压阳极氧化处理后的表面形貌、组织结构、硬度和耐蚀性。结果表明:铝合金经不同氧化电压阳极氧化处理后,其表面上存在纳米级的孔洞;随着氧化电压的增大,孔径逐渐增大,膜厚增加;阳极氧化膜的硬度在氧化电压为20V时最大;氧化电压对阳极氧化膜耐蚀性的影响很大,在氧化电压为5V时,阳极氧化膜的耐蚀性最强,自腐蚀电位为-1.1V。     

钛表面阳极化处理技术

通过对一台钛制设备阳极化处理工艺过程的详细介绍、氧化膜性能的考察及设备的跟踪调查,证明了阳极化处理后能提高钛制设备的硬度、耐磨性、耐蚀性和绝缘性。     

AZ 31镁合金阳极氧化工艺参数的优化研究

采用正交实验对AZ 31镁合金在碱性电解液中进行阳极氧化的工艺参数进行优化。考察了氧化时间、电流密度、脉冲频率和占空比对阳极氧化膜性能的影响,获得最佳阳极氧化工艺参数为:氧化时间15min,电流密度1.0A/dm2,脉冲频率200Hz,占空比10%。采用X射线衍射仪(XRD)、扫描电镜(SEM)和动电位极化曲线等检测手段研究了阳极氧化膜的结构、表面形貌和耐蚀性。结果表明:经优化工艺制得的阳极氧化膜,其主要成分为MgO,Al2O3和MgAl2O4,膜层孔隙分布均匀、致密,耐蚀性大幅提高。     

压铸镁合金阳极氧化膜的研究

研究了压铸镁合金AZ91的阳极氧化膜的工艺及其耐蚀性，探讨了镁合金表面阳极氧化膜的组织、相、成分及其耐蚀性。研究结果显示，压铸镁合金AZ91阳极氧化膜表面系氧化物的聚集，阳极氧化膜在3．5％NaCl中的极化曲线与AZ91压铸镁合金的极化曲线对比，阳极氧化膜的极化曲线有明显的钝化区，但在极化区只呈锯齿状变化，耐蚀性较好。     

电流密度对铝合金瓷质阳极氧化膜性能的影响

在草酸钛钾电解液中采用恒流模式对铝合金进行瓷质阳极氧化处理,研究了电流密度对瓷质阳极氧化膜的耐蚀性、厚度以及硬度的影响。结果表明:随着电流密度的增加,瓷质阳极氧化膜的耐蚀性、厚度以及硬度都有所提高;当电流密度为2.5A/dm2时,瓷质阳极氧化膜的耐蚀性最佳,厚度最大。     

电流密度对AZ31B镁合金阳极氧化及膜层性能的影响

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.     

铬酸阳极化中温去离子水封闭工艺研究

针对铬酸阳极化中温去离子水封闭工艺氧化膜水合度不易控制并且耐蚀性差的问题,研究了不同封闭温度下氧化膜的水合度以及阳极化保压时间等因素对耐蚀性的影响。结果表明:铬酸阳极化中温去离子水封闭工艺,封闭温度越低,达到水合度15%的封闭时间越长,耐蚀性也越差,延长阳极化保压时间可以提高阳极化膜的耐蚀性。采用封闭温度70℃,保压时间45 min的工艺参数可以很好控制15%的氧化膜水合度要求,并能够满足336 h盐雾试验的质量控制要求。     

EIS analysis of hydrophobic and hydrophilicTiO2 film

Titanium oxide films were formed on metallic titanium substrates by employing a thermal treatment at 800 °C under air atmosphere. Component and microstructure of the oxide films were characterized by XRD and SEM method. Water contact angles on titanium oxide film surface were measured in both dark and sunlight illumination condition. Corrosion tests were carried in seawater solution under different illuminate conditions. Electrochemical impedance spectroscopy (EIS) techniques were used to study the changes on TiO₂ film. Results indicated that: hydrophilic TiO₂ film suffered a severe photo-corrosion effect in seawater due to their semiconductor properties under sunlight condition, but the hydrophobic TiO₂ film under dark condition exhibited a good corrosion resistance.     

合金结构钢常温电化学发黑工艺研究

采用电化学的方法在合金结构钢表面形成一层黑色氧化膜。探讨了温度,时间,电流密度和添加剂等因素对膜层硬度和厚度的影响。该工艺简单,所得发黑膜硬度高,耐蚀性好。     

铝合金雕塑阳极氧化工艺的研究

对金属雕塑用的2024铝合金进行阳极氧化处理,并研究了电压对铝合金氧化膜的厚度、硬度、耐蚀性及表面形貌等的影响。结果表明:电压较低时,氧化膜较薄,耐蚀性不佳。适当升高电压,有利于提高氧化膜的厚度和硬度。但电压高于20V时,氧化膜的溶解速率增大,使得氧化膜的厚度和硬度下降。20V下得到的氧化膜具有最佳的耐蚀性。     

Effect of dissolved hydrogen on corrosion of Inconel Alloy 600 in high temperature hydrogenated water

Electronic property, microstructure and chemical composition of oxide films formed on Alloy 600 in high temperature water with various dissolved hydrogen (DH) levels that allow the Ni/NiO phase transition to occur were studied by employing electrochemical and exposure experiments. The results showed that increasing DH in water decreased the thickness and the ionic defect transport resistance of the oxide film, in conjunction with the increase of Cr- but decrease of Ni-concentrations in the oxide film. Further, it was found that DH weakened the stability and protectability of the Ni spinel oxide film. The DH effect was attributed to the oxidative dissolution process of Ni following the reduction of Ni in the oxide by H₂, indicating the selective dissolution of Ni in the oxide plays an important role in the corrosion of Ni-base alloys in high temperature hydrogenated water. Implications of the results of this work for mechanism of stress corrosion cracking in Ni-base alloys in high temperature hydrogenated water were discussed.     

6061铝合金常温脉冲硬质阳极氧化工艺研究

采用直流叠加脉冲电源,通过正交实验研究了占空比、电流密度和氧化时间对氧化膜厚度、显微硬度和耐磨性的影响.结果表明:在常温下,当占空比为50%,电流密度为5 A/dm2,氧化时间为30 min时,所得的氧化膜综合性能最好.     

Alkaline Corrosion Resistance of Anodized Aluminum Coated with Zirconium Oxide by a Sol-Gel Process

To improve the alkaline corrosion resistance of aluminum, composite films were prepared that consisted of a porous layer of anodically grown aluminum oxide filled with zirconium oxide, with a zirconium oxide coating layer that was deposited thereon via the sol—gel process, using a dip-coating technique. The alkaline corrosion resistance of these composite films was extremely improved when this coating layer was placed on an anodic oxide film. Comparisons of the composite film and conventional anodic oxide film showed that the alkaline corrosion resistance of the composite film was increased by a factor of 24–50. Because these composite films, which have high corrosion resistance, indicated a vibration phenomenon of voltage in the duration time curve of the electromotive force measurement, the composite film had a self-repairing action for alkaline corrosion.     

Corrosion behavior of 2024 aluminum alloy anodized in presence of permanganate and phosphate ions

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.     

钢铁中温锌-钙系黑磷化液研制

为了改善锌一钙系黑色磷化膜的外观和性能,配制了锌-钙系中温黑磷化液,研究了配位剂、总酸度、磷化时间对黑磷化膜厚度、金相形貌和耐蚀性的影响,采用X射线荧光光谱法(XRF)分析了磷化膜的成分.结果表明,采用柠檬酸三钠作配位荆,控制总酸度为50～100,磷化时间15～20 min,能够获得防护性能良好的黑色磷化膜.     

Surface analyses of anodic oxides films formed on Fe-3% Ti alloy

Surface analyses of the anodic oxide films formed on Fe—3% Ti alloy in deaerated pH 3.0 phosphate solution were performed with Auger electron spectroscopy (AES) and ellipsometry to evaluate the role of allying titanium in the corrosion resistance of iron.The 3%-addition of titanium reduced significantly the passivity-maintaining current density of iron as well as the maximum-active current density. Auger analysis revealed that titanium was enriched markedly in the anodic oxide films formed on Fe—3% Ti alloy and that a significant amount of phosphorus was distributed in the whole range of film thickness. Both the amount of titanium enriched in the film and the film thickness (20–40 nm) ellipsometrically obtained were proportional to the amount of electric charge required for passivation. Atomic absorption analysis of the solution indicated that the formation of a titanium-enriched film resulted from a preferential dissolution of iron as ferrous ions.From the measurement of the potential decay curves of the Fe—3% Ti alloy and pure iron electrodes passivated for different hours, it was concluded that the titanium-enriched layer promoted the passivity by suppressing, though incompletely, the active dissolution, whereas the substantial passivity of the alloy was attributed to the iron oxide film of barrier type formed at the interface of titanium-enriched layer/alloy substrate.     

电压对7N01铝合金阳极氧化膜结构及耐蚀性的影响

采用160 g/L硫酸溶液在17°C下对7N01铝合金阳极氧化30 min,氧化电压分别选取14、15、16、17和18 V。用扫描电镜观察所得阳极氧化膜的形貌,用能谱仪和电化学测量分析了它的成分、厚度和耐蚀性。结果表明,7N01铝合金经过不同电压下的阳极氧化处理后,表面均能形成凹凸不平并有孔洞的阳极氧化膜,电压为17 V时所制膜层致密、均匀,厚度约为7.6μm,耐蚀性最佳,在3.5%NaCl溶液中浸泡1440 h后没有明显的腐蚀。