共查询到20条相似文献,搜索用时 640 毫秒
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目前,电镀锌工业常用的Ca、Co系铅基合金阳极成本高、性能不佳,不能广泛应用,将WC和稀土CeO2掺杂入铅及其合金可望解决上述问题。采用脉冲电镀在铝基体上制备了Pb-WC-CeO2复合镀层用作阳极材料。考察了正向脉冲参数(平均电流密度Jm,占空比r及正向电流时间ton)及镀液温度对复合镀层在模拟锌电解液中用作惰性阳极时的电催化性能,从节能高效角度优选出了脉冲工艺:Jm=0.12 A/cm2,r=20%,ton=200 ms,温度50℃。在此工艺条件下获得了具有较低析氧电位、较好电催化活性的阳极材料。 相似文献
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锌-镍复合镀层耐蚀性优良,采用电镀、电刷镀和热浸镀获取镍-镍镀层有着许多问题.为此,采用锌粉、可溶性镍盐制备了锌-镍复合机械镀层.采用X射线衍射(XRD)和电感耦合等离子体发射光谱(ICP-AES)分析了镀层中镍的物相及含量;采用贴滤纸法检测了镀层的孔隙率;采用中性盐雾试验方法检测了镀层的耐腐蚀性能.结果表明,锌-镍复合机械镀层中存在Zn、Ni、Sn、Ni3Sn4、SnO,镍主要以单质形式存在;镀层的连通空隙率为零;镀层与基体间结合良好;镀层厚度相同时,锌-镍复合机械镀层的耐腐蚀性能优于纯锌机械镀层. 相似文献
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稀土在Ni-P和Ni-B基化学复合镀中的应用 总被引:13,自引:3,他引:10
研究了稀土对Ni-P和Ni-B基化学复合镀工艺及性能的影响。结果表明,添加少量稀土能显著地提高Ni-P和Ni-B基复合镀层中SiC的含量,从而提高其硬度和耐磨性。 相似文献
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铝及铝合金电镀高可焊性锡基合金工艺 总被引:2,自引:0,他引:2
重点对比了用浸锌、浸镍和磷酸阳极氧化两种铝及铝合金电镀前处理方法得到的锡基镀层的孔隙率,结合力、抗高温高湿性能、抗中性盐雾试验性能,分析了铝及铝合金锡基镀层在长期贮存过程中易变色、生霉、泛黑的原因,推荐了一种在铝及铝合金上电镀高抗变色性、高结合力、高可焊性的锡基镀层工艺。 相似文献
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This thesis mainly introduced the guiding principle and physical model of the research on the nano-composites coats of radar wave's absorption, and then studied the qualitative analysis of the performance ameliorating of radar wave's absorption composite coats. And on the basis of the optimum design of multilayer wave's absorption materials, two new kinds of radar wave's absorption composite coats have been made, which are composed of nano-composites hydroxyl iron powder and hollow micro-sphere. The research indicated that the surface-density of these two new composite coats is less than 3.5 Kg/m2.The coats' thickness is about 1 mm. And the waves absorption capability is above the level of 5 db, in the range of 3 ~ 18GHz. Therefore the wave's absorption performance of these two new coats is better than nano-crystalloid in low frequency area. The pilot study has proved that the nano-composites coat's performance of radar wave's absorption excels the ordinary radar wave's absorption coats, so it needs to be further studied. 相似文献
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镀液中SiC含量和粒径对Ni-P-SiC复合化学镀层性能的影响 总被引:7,自引:0,他引:7
采用化学镀方法制备了Ni P SiC复合镀层 ,系统研究了镀液中SiC含量和粒径对镀层结构及显微硬度的影响。结果表明 ,镀层中SiC析出量随镀液中SiC含量的增加而增加 ,在SiC含量一定的情况下 ,当SiC粒径为 7.0 μm时 ,析出量最大 ;镀液中SiC的含量和粒度对原始镀层的硬度影响不大 ,但对 4 0 0℃热处理后的镀层硬度有显著影响 相似文献
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纳米ZnO复合食品抗菌包装膜研究进展 总被引:5,自引:4,他引:1
目的介绍纳米氧化锌在食品抗菌包装膜中的研究现状。方法总结纳米氧化锌在包装膜材中的应用,并指出当前研究的不足和未来研究趋势。结论纳米Zn O的粒径、形貌、分散性、活化程度、添加量等对其在不同包装基材系统中的抗菌效果有很大的影响。纳米Zn O在不同包装基材中的迁移研究还不完善,需要进一步研究其迁移机理,预测其迁移模型。单一添加纳米Zn O的研究较多,纳米Zn O与具有其他功能物质复合使用的研究较少,而复合使用是未来纳米Zn O复合抗菌包装研究领域的重点。 相似文献
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Microwave-assisted synthesis and characterization of zinc oxide/carbon nanotube composites 总被引:1,自引:0,他引:1
A composite material of zinc oxide and carbon nanotubes were successfully synthesized via a sol process using zinc acetate dihydrate and treated multi-wall carbon nanotubes under microwave irradiation. The morphology, microstructure and chemical bonding of as-obtained composites were well characterized using X-ray diffraction, scanning electron microscope, transmission electron microscope, and Fourier transform infrared spectroscopy. Zinc oxide nanoparticles were dispersively coated on the surface of carbon nanotube when the precursor was dried under microwave irradiation without post-annealing. X-ray diffraction results obviously showed the mixture of two phases of carbon nanotube and wurzite zinc oxide whose size is approximately 15 nm. The formation of zinc oxide nanoparticles on carbon nanotube surface in the composite prepared by microwave heating is much better than the composite heated by conventional annealing. Fourier transform infrared spectroscopic results suggest that carboxylic groups and uniform heating by microwave heating could play key roles on the nucleation of zinc oxide on carbon nanotube surface. 相似文献
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W. Wu Y-W. Cai J-F. Chen S-L. Shen A. Martin L-X. Wen 《Journal of Materials Science》2006,41(18):5845-5850
In this paper, composite particles of nano zinc oxide coated with titanium dioxide were prepared and characterized by TEM, XRD, XPS and FT-IR, and the properties of the composite particles for photo catalysis and light absorption were studied. Tetrabutyl titanate (TBT) was hydrolyzed in an alcoholic suspension of nano zinc oxide with diethanolamine (DEA) as an additive, resulting in a film with a thickness of 20–30 nm being coated on the surface of nano zinc oxide, and the composite particles contained ZnTiO3 after drying and calcination. Photocatalysis capabilities of the composite particles for the degradation of phenol in an aqueous solution were greatly improved as compared with nano zinc oxide particles before coating, with pure nano ZnO and nano TiO2 with similar average sizes, or with the mixture of nano ZnO and TiO2 with the similar composition as the composite particles. The light absorption scope of the composite particles was enlarged when compared to nano titanium dioxide with same average size. 相似文献
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In the present work, we investigate the surface, and bulk structural properties of composite cupric oxide ribbons, and zinc oxide particles. The composites are synthesized using the technique of solution combustion. Crystallographic phases are confirmed using the x-ray diffraction technique and proved the formation of monoclinic cupric oxide and hexagonal zinc oxide crystallites. Scanning electron microscope and high-resolution transmission electron microscope are used to examine the morphology of the prepared materials. Composite mixtures of raw particles cupric oxide and zinc oxide are used as benchmark morphologically-alike composite materials. The specific surface area values of the studied materials are investigated using nitrogen gas adsorption at 77 K while the spectroscopic gamma ray attenuation is used to determine the effective density of the different samples. Zinc oxide particles are dispersed on cupric oxide ribbons and cause nonlinear dependence of the specific surface area and density on the composition ratio due to the physical contact between particles, especially at the voids and the nodes of the fibrous ribbons network. 相似文献
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A simple synthesis route was designed to fabricate a functional composite, zinc hydroxide carbonate (ZHC) flowers on zinc oxide (ZnO) nanorods. The hydrolysis of hexamethylenetetramine (HMT) can generate various species which are slowly released and gradually change reaction modes in a Zn(NO(3))(2)/HMT solution. As a result, ZnO nanorods and ZHC flowers can be sequentially synthesized and connect very well under constant experimental conditions. The obtained composite has the advantages of both components and exhibits attractive properties. For instance, ZHC flowers on ZnO nanorods exhibit strong blue emission under the excitation of ultraviolet light, and dye-sensitized solar cells with the annealed composite as photoanode achieve much higher conversion efficiency than pure nanorod arrays. 相似文献