Zirconium Oxide Coating on Anodized Aluminum by the Sol-Gel Process Combined with Ultraviolet Irradiation at Ambient Temperature

Instead of the conventional sol-gel process in which heat treatment is used to form a dense composite film after dipping/withdrawing a substrate into/from the sol, a new sol-gel process incorporating ultraviolet (UV) irradiation at ambient temperature has been attempted to improve the alkaline corrosion resistance of aluminum. A sol-gel film prepared by UV irradiation at ambient temperature indicated that alkaline corrosion resistance is superior in the range of 2.4 times to 2.6 times that of the conventional composite film heated at 573 K. The densification of the coating layer due to the elimination of residual organics induced by photoexcitation was responsible for the improvement in alkaline corrosion resistance. The high alkaline corrosion resistance of the irradiated film may be attributed to the formation of a dense coating layer and the self-repairing action caused by repetition for preparation and dissolution of the reactant in the penetrating path of NaOH solution into the composite film.     

铜包铝线腐蚀过程与机理初探

采用扫描电镜、金相显微镜和电化学工作站等对铜包铝线小孔腐蚀和电偶腐蚀的表面形貌、腐蚀速度和特点展开系统研究。分析了镀层保护期、局部脱层期和腐蚀破坏期等不同阶段特点。分析了腐蚀机理,探讨了腐蚀和镀层与基体的结合力的关系。对电镀工艺和镀后处理方法提出了改进意见和措施。     

Conventional and Microwave-Induced Sintering Mechanisms for Reaction-Bonded Aluminum Oxide with Zirconium Oxide Additions

Powder compacts consisting of Al, Al₂O₃, and ZrO₂ were heated by microwave radiation. Tracing the phase evolution during reaction bonding revealed the reaction mechanism. In the case of conventional heating, the compacts expanded slightly at temperatures of <700°C due to Al surface oxidation and expanded sharply at temperatures greater than 700°C as oxidation proceeded from the surface to the interior. Then, the compacts shrank at 1550°C due to sintering. For the case of microwave heating, the compacts expanded at temperatures of <550°C due to the formation of Al₃Zr. This Al₃Zr formation was caused by the preferential heating of ZrO₂ relative to Al and Al₂O₃ by microwave radiation. Then, Al₃Zr was oxidized to form Al₂O₃ and ZrO₂ at temperatures of >1000°C. Finally, the compacts shrank at 1550°C due to sintering, similarly to conventional sintering.     

Effects of Zirconium Oxide on the Reaction Bonding of Aluminum Oxide

In the reaction-bonded aluminum oxide (RBAO) process, attrition-milled Al/Al₂O₃ powder compacts are reacted in air to form Al₂O₃-based ceramics. Typically, ZrO₂ powder is added to control the final microstructure and properties, resulting in fine-grained, high-strength materials. In this study, the effects of ZrO₂ on the reactivity of RBAO samples were examined using thermogravimetric analysis, X-ray diffractometry, and other techniques. Previously, it was shown that a self-propagating reaction could occur during firing of RBAO in air. This reaction was attributed solely to the fast and highly exothermic oxidation of the aluminum on the surface of the sample, but the results of the current study show that it is related to a reaction between aluminum and ZrO₂, forming Al₂O₃ and Al₃Zr. As a consequence, a new reaction sequence for RBAO consistent with these observations has been proposed.     

不锈钢表面涂覆TiO2薄膜的耐蚀性研究

以钛酸丁酯为原料,采用溶胶-凝胶技术,在不添加其他溶剂的情况下在201型不锈钢基体上制备了TiO2薄膜,采用金相显微镜观察薄膜表面形貌,利用X-射线衍射仪对其晶型进行了表征,同时测量了薄膜试样的极化曲线,实验结果表明:在不锈钢表面涂覆TiO2薄膜能够增强不锈钢基体的耐蚀性。     

溶胶凝胶法合成氧化锰八面体分子筛

非离子表面活性剂聚乙二醇1000调控的溶胶凝胶法合成了氧化锰八面体分子筛(OMS-2)。采用XRD、BET、TEM、O2-TPD等技术对制备的材料的结构和氧化还原性能进行了表征,考察了制备锰氧化物材料对二甲醚催化燃烧反应的催化性能。结果表明,合成的OMS-2材料属于cryptomelane一维隧道结构,得到的纳米材料为均一的纳米棒状结构。O2-TPD结果表明,制备的OMS-2材料具有比较丰富的氧物种,因而在二甲醚催化燃烧中表现出了良好的催化性能。     

非水解溶胶-凝胶过程制备锡/硅复合氧化物

以无水四氯化锡和正硅酸乙酯为前驱物、环己烷为溶剂,在无氧无水条件下采用非水解溶胶-凝胶过程制备了锡/硅复合氧化物,并对其进行了表征分析。结果表明,在原料Sn/Si摩尔比为1∶2、反应温度为30℃、焙烧温度为500℃时,所得复合氧化物的产率为31.3%,Sn/Si摩尔比为7.4∶1,粒径10nm左右,比表面积22.58cm2.g-1,平均孔径14.3nm,比孔容0.047cm3.g-1,主要为颗粒堆积孔;复合氧化物的主要组成为无定形氧化硅和氧化锡晶体,在焙烧温度达到500～600℃时仍有Sn-O-Si杂键存在。     

铝合金阳极氧化着黑色热控涂层工艺研究

介绍了一种铝合金阳极氧化着黑色热控涂层工艺,此工艺采用硫酸阳极氧化方法以及深黑32#有机染料着色,对LY12铝合金H112热处理状态材料进行了处理。通过正交试验对氧化时间、氧化温度、电流密度工艺参数进行优化,得到高发射率的最佳工艺参数。     

Yellow Coatings Produced on Glasses and Aluminum by the Sol-Gel Process

The preparation of CeO₂-TiO₂ coatings by the sol-gel dip-coating process, with curing at 500°C, was studied. The films were brilliant yellow and adherent to soda-lime glass, a PbO-containing glass, and aluminum foil. The transmittance, chromaticity, thickness, phase content, and surface microstructure of the films were determined.     

表面处理条件不同对锆铝包覆类型钛白粉产品质量的影响

从无机包覆条件和不同的有机处理方式,研究了锆铝包覆类型的钛白粉,对产品质量的各影响因素,特别是引起吸油量指标偏高的因素,做出了评价。结果表明,打浆分散剂的选择、无机包覆量和无机处理选择合适的条件,有机处理使用硅烷偶联剂能够在溶剂型涂料和油墨中获得卓越的吸油量和良好的分散性。     

铈盐封孔对建筑铝合金阳极氧化膜耐蚀性的影响

选取建筑常用的铝合金6063作基体,阳极氧化后采用铈盐封孔,并研究铈盐封孔工艺参数对封孔后阳极氧化膜腐蚀失重的影响.结果表明:随着双氧水浓度从0 mL/L增加到9 mL/L、硝酸铈浓度从2.5 g/L增加到9.0 g/L、温度从25℃升高到65℃、封孔时间从10 min延长到50 min,封孔后阳极氧化膜的腐蚀失重都呈...     

Effect of Chemical Composition of Tetraethoxysilane and Trimethoxy(Propyl)Silane Hybrid Sol on Hydrophobicity and Corrosion Resistance of Anodized Aluminum

Silicon - The current study indicates the application of three different range of hybrid sols on substrates. The aim was to achieve an optimum chemical composition on the silane- treated surface in...     

Alkaline Titanium-Silicate Glasses for White Glass Enamels with Enhanced Corrosion Resistance

The properties of alkali borotitanium-silicate glasses with different content of boron, titanium, and lithium oxides are investigated. It is indicated that glasses with a low content of B₂O₃ (8 – 10%) can be used to produce white glass-enamel coatings that have enhanced corrosion resistance and low leachability of the coating components in acetate solutions. __________ Translated from Steklo i Keramika, No. 7, pp. 31 – 33, July, 2005.     

Seeding of the Reaction-Bonded Aluminum Oxide Process

The effect of the initial α-Al₂O₃ particle size in the reaction-bonded aluminum oxide (RBAO) process on the phase transformation of aluminum-derived γ-Al₂O₃ to α-Al₂O₃, and subsequently densification, was investigated. It has been demonstrated that if the initial α-Al₂O₃ particles are fine (∼0.2 μm, i.e., 2.9 × 10¹⁴γ-Al₂O₃ particles/cm³), then they seed the phase transformation. The fine α-Al₂O₃ decreases the transformation temperature to ∼962°C and results in a finer microstructure. The smaller particle size of the seeded RBAO decreases the sintering temperature to as low as ∼1135°C. The results confirm that seeding can be utilized to improve phase transformations and densification and subsequently to tailor final microstructures in RBAO-derived ceramics.     

铝合金基体上多层组合镀层的耐蚀性研究

本文结合电化学腐蚀原理及产品实际使用环境,在镍-磷合金/金双镀层基础上建立了镍-磷合金/铜/镍-磷合金/金的多层组合镀层,分析了多层组合镀层的腐蚀机理,并对其耐蚀性能进行了验证。结果表明,镍-磷合金/铜/镍-磷合金/金的多层组合镀层可满足航空产品耐192 h盐雾腐蚀的使用要求,可有效提高材料的防护性能。     

Some Experiments in Comparing the Resistance of Enamels to Corrosion by Alkaline Solutions

Experiments are described which show the effects of solution temperature, concentration, container material, and specimen position on the rate of dissolution of sheet-steel and cast-iron enamels by alkaline solutions. The results indicate that in designing apparatus to measure such corrosion rates the solution temperature should be controlled to at least ±0.1°C., that no glass parts of the apparatus should be exposed to the solution, and that, in the absence of stirring, consideration should be given to the positioning of the specimens. Corrosion test apparatus is described which was designed to meet these requirements.     

铝材碱性电解抛光工艺的研究

针对铝材酸性电解抛光工艺废水污染严重的问题,对碱性电解抛光工艺进行了研究,并确定了碱性电解抛光中各种药品的用量及运行条件。结果表明:碱性电解抛光技术在一定程度上能够满足铝材抛光的需求。通过实验,获得了抛光效果好、使用寿命长、无磷的抛光液。     

无铬封闭处理对ZL101A铝合金阳极氧化膜耐蚀性能的影响

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...