刷镀锌的应用及锌层的退除

锌是两性金属,易溶于酸,也易溶于碱。其氧化物和氢氧化物也都是两性化合物。锌在干燥的空气中较稳定,在潮湿空气与含有二氧化碳和氧的水中,表面会生成一层致密的以碱式碳酸锌为主的覆盖膜,起到保护内部金属的作用。锌的电极电位较负（－０．７６　Ｖ）,对铁而言,它属阳极性镀层。在钢铁件上刷镀锌层时,二都能形成原电池,锌镀层作为原电池的阳极受到腐蚀,可使钢铁基体受到电化学保护。１镀锌溶液及工艺（１）碱性镀锌该溶液呈微黄色,ｐＨ值为１０．８,锌含量６５．４　ｇ／Ｌ,耗电系数０．０２　Ａ·ｈ／ｄｍ２·μｍ,镀…     

电镀锌及锌合金镀层钝化处理的应用与发展

电镀锌及锌合金广泛用于钢铁表面的防护,钝化处理后可进一步提高其耐蚀性。目前,广泛用铬酸盐作钝化处理。由于六价铬毒性大,严重污染环境,近来人们在研究和使用无六价铬钝化工艺,并取得了一定的效果。尽管用一些新工艺处理的钝化膜的耐蚀性已接近铬酸盐钝化膜,但还需进一步提高。     

Interaction of Zn and Zn–4Al,Zn–15Al (wt-%) solder alloys with aluminium

The interaction of pure zinc and Zn–4Al, Zn–15Al (wt-%) solder alloys with aluminium has been investigated. Two different experimental techniques were used: (i) the aluminium samples soldering and (ii) the holding of liquid solder alloys inside the hollow in an aluminium base. The aluminium content was determined in samples after contact with aluminium at various temperatures and various holding times. It is shown that in soldered seams and solder alloys that had been held inside the aluminium base, the content of the aluminium was higher than at the points on the liquidus line on the Zn–Al equilibrium phase diagram at the corresponding temperatures and increases along with an increase in the holding time. This was apparently due to isothermal solidification.     

Self-Assembled Protein Nanofilm Regulating Uniform Zn Nucleation and Deposition Enabling Long-Life Zn Anodes

Rechargeable zinc-ion batteries (RZIBs) have gained promising attention as a feasible alternative for large-scale energy storage by the virtue of their intrinsic security, environmental benignity, low cost, and high volumetric capacity (5849 mAh cm⁻³). Nevertheless, the deep-rooted issues of dendrite formation and side reactions in unstable Zn metal anode have impeded RZIBs from being dependably deployed in their proposed applications. Herein, silk fibroin (SF) and lysozyme (ly), as natural biomacromolecules with abundant polar groups arranged in polypeptide backbones, are in situ self-assembled on the Zn anode surface to construct a homogeneous and compact protein nanofilm. Such protein nanofilm protecting layer presents a negative charge surface and significantly regulates Zn²⁺ deposition behavior. Meanwhile, synergistic flexible and robust features of protein nanofilm function as artificial solid electrolyte interface (SEI), accommodates the dynamic volume deformation during deposition/dissolution, and blocks corrosion of side reactions. Consequently, the electrochemical stability of protein nanofilm-modified Zn anode is greatly improved, with an excellent extended lifespan of over 1100 h at a high current density of 10 mA cm⁻² and a high cycling capacity of 10 mAh cm⁻², corresponding to a high depth of discharge (83% DOD_Zn). Furthermore, the highly reversible Zn electrode remarkably improved the overall performance of MnO₂||Zn full-cells.     

水解锌制备Zn/ZnO纳米结构及其光学性能研究

利用滚压振动磨在干法室温条件下将金属锌制备成尺度约为3~5nm的锌量子点,并使产物与水蒸气在250℃进行化学反应,得到纳米氧化锌或纳米氧化锌与锌的混合物。分别利用能量发射谱仪(EDS)、透射电镜(TEM)对样品成分和形貌进行了表征。结果表明,250℃反应温度下得到的产物具有良好的分散性,其特征是棒状和片状结构共存,而且纳米棒具有显著的沿[011 1]晶向生长的趋势。室温下光致发光(PL)谱显示,在360nm和388nm处有双紫外发射峰,属于激子态发光,双紫外发射峰可能与掺杂能级有关;同时,在496nm处有蓝光发射峰,在515nm处有绿光发射峰,这两种发射属于表面缺陷态发光。对各种发光峰的发光机制进行了讨论。UV-Vis吸收光谱表明,产物在紫外区有很强的紫外吸收,吸收峰出现了蓝移现象,验证了Zn纳米量子点的掺杂形成掺杂能级,也与测得的可见光发射一致。     

Structure and luminescence of (Zn,Mg)O:Zn nanophosphor films

A versatile homogeneous solution growth method is developed for depositing (Zn,Mg)O:Zn²⁺ nanophosphor films from aqueous solutions of zinc, magnesium and triethanolamine. The effect of pH on the structural and morphology of (Zn,Mg)O:Zn²⁺ nanophosphor films was studied and the optimum deposition conditions have been outlined. The deposition rate of nanophosphor film at neutral pH condition was comparatively larger than in basic conditions. The as-deposited films exhibit good crystallinity with hexagonal wurtzite crystalline structure and preferably oriented along (0 0 2) plane. With time, the nanophosphor films appeared dense on the glass substrate comprising of particle sizes of 30-50 nm. Upon excitation at 326 nm, photoluminescence (PL) spectrum corresponding to deep level impurities (∼ 410-530 nm) was completely masked by the strong blue-green emission at ∼ 456 nm. The ratio of Mg to Zn was optimized for maximum PL brightness whereas the optical transmittance of the nanophosphor film decreased with increasing thickness.     

蒸发制备锌镁合金镀层中锌镁层的扩散研究

锌镁合金镀层是一种具有优异防腐蚀性能的新型钢板保护镀层,真空镀由于其优良的镀层性能正逐步发展为锌镁合金镀层的重要制备工艺。本文在镀锌钢板表面采用真空热蒸发镀镁,再由快速退火工艺形成锌镁合金镀层。通过X射线衍射、二次离子质谱和扫描电镜分析了在退火过程中锌、镁层的扩散过程,并通过盐雾试验和电化学测试研究扩散过程对锌镁合金镀层腐蚀性能的影响。研究发现:退火过程中镁快速向锌层扩散,并在锌层内一定深度处富集,而锌逐渐向镁层扩散,这种相互扩散形成了锌镁合金。同时铁也会向锌层扩散,形成锌铁合金。镁富集区具有扩散阻挡作用,阻止镁进一步向内扩散的同时也阻止铁向表面的扩散。腐蚀性能测试表明,370℃下退火60～120 s的样品具有较好防腐蚀性能。     

双波长分光光度法连续测定锌镍合金镀液中Zn2+与Ni2+的含量

采用分光光度计和比色管,研究了以XO为显色剂并用双波长分光光度法测定电镀Zn-Ni合金溶液中的Zn     

Korrosionsuntersuchungen an mittels PVD mit Zn und Zn/Mn beschichteten Stählen

Corrosion Studies of Steels Coated by means of PVD with Zn and Zn/Mn Alternative methods for hot dip‐ or electrogalvanic deposition of zinc coatings on steel are gas phase depositions (PVD). They posess high flexibility with respect to alloy composition, and are environmentally harmless. However, a PVD‐coated steel must have at least the same corrosion resistance than steels with “classical” surface finishing. Therefore, the corrosion behaviour of Zn‐coatings and Zn/Mn/system‐coatings deposited by electron beam evaporation without and with ion beam assistance (IBAD) on low alloy steel, was determined by means of salt spray test and electrochemical potential/time measurements. At first the influence of chemical and irradiation pre‐treatment and ion bombardment during deposition on the corrosion resistance of the coatings was investigated. Than the effect of the Zn‐layer thickness was determined in comparison with an 8μm thick electrogalvanized reference coating. Finally Zn/Mn‐alloys, Zn/Mn‐multilayers and Zn‐coatings with Mn‐ or Zn/Mn‐surface layers (top layers) were investigated. By means of optimised pre‐treatment and ion bombardment conditions one obtains, considering the layer thickness, PVD‐Zn coatings with corrosion resistance comparable with the reference layer. The best Mn‐containing coatings are Zn‐coatings with Mn‐toplayer. They surpass the corrosion resistance of the reference layer considerably. Additionally it could be shown that in tendency the potential/time measurements agree very well with the results of the salt spray test.     

Pinless Friction Stir Spot Welding of Mg-3Al-1Zn Alloy with Zn Interlayer

With the addition of a thin Zn interlayer,2.4 mm thick Mg-3Al-1Zn alloy sheets were friction stir spot welded(FSSW) using a pinless tool with flat,convex and concave shoulder shapes. The results showed that an alloying reaction took place between the Mg substrate and Zn interlayer during FSSW,forming a discontinuous intermetallics layer composed of dispersive(α-Mg+MgZn) eutectic structure underneath the shoulder and a Mg-Zn intermetallics bonding zone at the outside of the joints. This alloying reaction increased the bonded area and eliminated the hook defects,thereby producing sound FSSW joints with a shallow keyhole without hook defects. The increase of plunge depth was beneficial to the Mg-Zn diffusion,thereby increasing the tensile-shear load of the joints. However,excessive plunge depths resulted in a decrease of the effective sheet thickness,reducing the strength of the joints. At a small plunge depth,the convex and concave shoulders were more beneficial to the interface reaction than the flat shoulder. The maximum joint load of 6.6 kN was achieved by using the concave shoulder at a plunge depth of 1.0 mm. A post-welding heat treatment promoted the dissolution of the discontinuous reaction layer in the joints; however,it led to the occurrence of void defects,influencing the bonding strength.     

Zn/Fe及Zn/Fe-Mn固态扩散偶中金属间化合物的生长

采用Zn/Fe及Zn/Fe-Mn固固扩散偶方法,研究了锰对金属间化合物生长动力学的影响。对扩散偶在385℃扩散10～300min的研究结果表明,在Zn/Fe扩散偶中,扩散层以δ相为主,ζ相和δ相之间具有平直的界面,随扩散时间的延长,δ相的厚度增加,ζ相逐渐被消耗,厚度比dζ/dδ的值逐渐减小;在Zn/Fe-Mn扩散偶中,扩散层也以δ相为主,ζ相和δ相之间的界面更平直,铁基体中的锰在扩散初期促进δ相的生长,但在扩散后期促进ζ相生长。对Zn/Fe-Mn扩散偶中金属间化合物的生长动力学研究表明,0.4%(质量分数,下同)的锰使扩散层总厚度增加,当锰含量增加到1.2%以上时,扩散层总厚度反而开始下降。Zn/Fe、Zn/Fe-0.4%Mn、Zn/Fe-1.2%Mn及Zn/Fe-2.0%Mn四个扩散偶中总扩散层的生长均由扩散控制。     

Homogenizing Zn Deposition in Hierarchical Nanoporous Cu for a High-Current,High Areal-Capacity Zn Flow Battery

A Zn anode can offset the low energy density of a flow battery for a balanced approach toward electricity storage. Yet, when targeting inexpensive, long-duration storage, the battery demands a thick Zn deposit in a porous framework, whose heterogeneity triggers frequent dendrite formation and jeopardizes the stability of the battery. Here, Cu foam is transferred into a hierarchical nanoporous electrode to homogenize the deposition. It begins with alloying the foam with Zn to form Cu₅Zn₈, whose depth is controlled to retain the large pores for a hydraulic permeability ≈10⁻¹¹ m². Dealloying follows to create nanoscale pores and abundant fine pits below 10 nm, where Zn can nucleate preferentially due to the Gibbs–Thomson effect, as supported by a density functional theory simulation. Morphological evolution monitored by in situ microscopy confirms uniform Zn deposition. The electrode delivers 200 h of stable cycles in a Zn–I₂ flow battery at 60 mAh cm⁻² and 60 mA cm⁻², performance that meets practical demands.     

鳞片状超微锌粉制备工艺的研究

研究了包覆剂、研磨剂及其添加量、轧制和球磨等工艺参数对超微锌粉性能的影响,结果表明,以最佳制备工艺获得的锌粉呈鳞片状,中位径为23.72μm,90%集中在10～40μm之间,厚度在0.1～0.6μm之间,氧化度为6.02%,白亮度较好。     

Single-atom Zn for boosting supercapacitor performance

Single-atom metal-incorporated carbon nanomaterials(CMs)have shown great potential towards broad catalytic applications.In this work,we show that N-doped porous...     

Sn–Zn low temperature solder

Low temperature soldering is one of the key technologies before the accomplishment of total lead-free conversion in electronics industries. While Sn-Zn eutectic alloy has excellent properties as low temperature solder, it has some drawbacks. Damage by heat exposure and corrosion in humidity are two of the main concerns. Zn has an important role in chemical properties. The material physical properties, wetting, chemical stabilities and various reliabilities have been well understood on this alloy system through the numerous past works. The understanding of both materials and processing aspects enables one to manufacture sound electronic products without any serious problems. The basic properties and the current understandings on the limit of the application of this solder are reviewed in this paper.     

Optical and EPR spectroscopy of Zn:Cr:ZnSe and Zn:Fe:ZnSe crystals

Optical and EPR characterization of Cr and Fe doped ZnSe crystals annealed in Zn vapor revealed a strong bleaching of the divalent state of transition metal ions. Photo induced EPR kinetics were studied in 20–80 K temperature range. Analysis of time-dependent data reveals Cr¹⁺ signal rise time decreases with increasing temperature. The non-exponential decay of Cr¹⁺ concentration were analyzed using Auger-type recombination process. The photoluminescence quantum yield of Cr²⁺ ions at ⁵E(D) → ⁵T₂(D) mid-IR transition excited via chromium ionization process was measured to be close to 100%.     

Interfacial characteristics of Zn/AZ31/Zn clad sheets fabricated by hot roll-bonding and annealing

The Zn/AZ31/Zn tri-layer clad sheets are prepared by hot roll-bonding technology and post-roll annealing in this study and the interfacial microstructure, mechanical and corrosion properties are investigated. The annealing temperature can influence the interfacial bonding behaviour. Upon annealing at 200°C, a good metallurgical bonding interface composed of Mg₄Zn₇ and MgZn₂ phases is obtained. A higher temperature (300°C) can induce the precipitation of the brittle Mg₂Zn₁₁ phase at the interface. The clad sheets annealed at 200°C can attain the maximum bonding strength among all the clad sheets investigated. Importantly, the corrosion rate can be obviously reduced by cladding pure Zn layer on both sides of AZ31 alloys, which provides another effective method to improve the corrosion resistance of magnesium alloys.     

Vibration behavior of light metals: Al–Zn alloy and Mg–Al–Zn alloy

Both Al–Zn alloy and Mg–Al–Zn alloy are considered as high damping and light materials. This study investigated the effects of the structure and the composition on the vibration fracture characteristics of the Al–xZn alloy and the Mg–xAl–Zn alloy under resonance. For Al–xZn (x = 7, 11, 49, and 83 wt.%) alloys, under both constant force and initial-deflection conditions, the 7Zn specimen showed the greatest vibration life. For Mg–xAl–Zn (x = 3, 6, and 9 wt.%) alloys, experimental results indicate that the AZ31-F as-extruded samples showed a greater vibration life, while high Al fully annealed samples (AZ91-O) had greater vibration fracture resistance under constant force conditions.