水性丙烯酸树脂作为金属表面钝化剂的研究现状

水性丙烯酸树脂作为金属表面处理剂已经有广泛的研究和应用。综述了水性丙烯酸树脂作为主要成膜物质在金属基体钝化成膜的方法、种类及其研究进展,指出其钝化膜的耐蚀性与铬酸盐钝化膜相当,有些甚至超过了铬酸盐钝化膜,具有替代铬酸盐钝化膜的潜力。     

镀锌层三价铬钝化膜的制备工艺及性能研究

为了提高镀锌钢板的耐蚀性,采用三价铬钝化液对镀锌层进行了钝化处理。研究了钝化工艺参数对钝化膜外观和耐蚀性的影响,确定了三价铬钝化最佳工艺。测试表明:制备的钝化膜的耐蚀性与六价铬钝化膜相当。通过SEM,EDS,XRD和极化曲线分析了膜层的形貌、成分及耐腐蚀性能。结果显示,钝化膜主要含有ZnO,FeCr,ZnCrxOy等物质,这些物质构成了平整致密的膜层保护金属基体,从而提高了金属的耐蚀性。     

镀锌层钼酸盐钝化膜腐蚀行为的研究

钼酸盐钝化能够显著提高镀锌层的耐腐蚀能力。一定工艺下获得的钼酸盐钝化膜的耐蚀性与铬酸盐钝化膜的耐蚀性相当,在酸性腐蚀介质下甚至可优于铬酸盐钝化。钼酸盐钝化中存在裂纹会降低钝化膜在中性盐雾腐蚀或盐水浸泡腐蚀中的耐蚀能力,而在酸性盐雾腐蚀下钝化膜的耐蚀能力则主要取决于钝化膜厚度。钼酸盐钝化膜能阻滞锌层在5％NaCl水溶液中腐蚀的阴极过程,使腐蚀电流显著减小。     

铝合金环保型钝化及其与漆膜的配套性能

为了进一步提高三价铬钝化膜的耐蚀性及其与漆膜的配套性能,以2024铝合金为基材,筛选出钝化液中的配位剂和缓蚀剂,并确定其工艺条件,开发了一种性能优良的环保型三价铬钝化液。结果表明：经硅溶胶封闭处理后的三价铬钝化膜结构致密,电化学性能优良,耐中性盐雾试验可达168h,其耐蚀性与Alodine1200六价铬钝化工艺相当;与环氧底漆和聚氨酯面漆的配套性好。     

铝上低电阻铬酸盐转化膜工艺研究

在工作中,采用三种铬酸盐化溶液,对几种牌号铝材进行了铬酸盐化处理,得到低电阻—耐蚀性铬酸盐膜。用盐雾试验和电化学方法评价了铬酸盐膜的耐蚀性;用凯尔文电桥测量了表面膜接触电阻。结果表明用1~#和2~#溶液得到的铬酸盐膜,在耐蚀性和导电性能方面都能满足使用要求。     

镀锌层上有机物无铬钝化涂层的耐蚀性

选择了一种无毒的水溶性丙烯酸树脂（AC）加入至钼酸盐、磷酸盐中（M）得到一种钝化液（ACM），对镀锌层进行钝化处理以代替有毒的铬酸盐钝化。通过盐雾试验、扫描电镜、电化学测试等手段，研究了该纯化膜的耐蚀性及耐蚀机理。结果表明，热浸镀锌层采用该无毒钝化液进行钝化，可以推迟镀锌层出现白锈的时间，其抗蚀性已接近铬酸盐钝化水平；ACM钝化膜耐蚀性的提高是由于钝化膜中的钼酸盐与丙烯酸树脂产生交联作用，抑制钝化膜裂纹的扩展，同时由于膜层中钼酸盐的缓蚀作用，提高了镀锌层的抗蚀性。     

热浸镀55%铝锌合金镀层钢板的铬酸盐钝化试验

对热浸镀５５％铝锌合金镀层钢板进行了铬酸盐钝化，研究了钝化膜的组成、耐蚀性及耐高温性能的影响。     

锌镀层硅酸盐钝化膜的耐腐蚀性能

为了考察锌镀层硅酸盐钝化膜的耐腐蚀性能,通过中性盐雾试验、3%CuSO4点滴试验对比研究了锌镀层、硅酸盐钝化膜及低铬酸盐钝化膜的耐腐蚀性能,并用极化曲线电化学测试方法研究了硅酸盐钝化膜的电化学性能。结果表明:硅酸盐钝化膜明显提高了锌镀层的耐腐蚀性能,其耐蚀性优于低铬酸盐钝化膜;硅酸盐钝化膜也明显提高了锌镀层的自腐蚀电位,有效地控制了其腐蚀的电化学过程,属阳极控制型。锌镀层硅酸盐钝化膜具有较高的耐蚀性能。     

家用电器热镀锌钢板的无铬耐指纹钝化

传统热镀锌钢板钝化工艺以铬酸盐体系为主,污染严重.以有机硅为主开发出了有机无机复合钝化剂,通过调整工艺参数在热镀锌钢板表面获得了较理想的钝化膜.考察了钝化膜膜厚、均匀性与各工艺参数之间的关系;探讨了不同钝化膜厚度对热镀锌钢板耐蚀性、耐指纹性、导电性及耐高温黄变性的影响.结果表明:无铬钝化膜的性能与铬酸盐转化膜基本一致,...     

镀锌层钛溶胶钝化及其耐蚀性

为了进一步提高镀锌层的耐蚀性而又利于环保,配制了钛溶胶,并在镀锌层表面涂覆成膜。分析了钛溶胶钝化成膜机理,研究了钛酸四丁酯含量、钝化液pH值、钝化时间及钝化后热处理温度对钝化膜耐蚀性的影响,用扫描电镜(SEM)观察了钝化膜的微观形貌。结果表明:当钛酸四丁酯含量为12.5 mL/L,钝化液pH值1.3,钝化时间15 s,热处理温度40℃时,钝化膜具有较好的防护性能;镀锌层经钛溶胶钝化处理后,表面趋于致密,同时更加平整,有利于进一步提高镀锌层的防护性能。     

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…     

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。     

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.     

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。     

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.     

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.     

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。     

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%.     

Preparation of isotopic Zn and Cd targets

^nat,68Zn and ^natCd have been reduced from their oxides with high yields (about 90%) using carbon as reductant. A water-cooled copper pin collector was used resulting in higher yield and better reproducibility. ^natZn and ^{nat, 113, 116}Cd targets of 20–3000 μg/cm² on carbon backings of 20 μg/cm² have been deposited by focused ion beam sputtering. ^{67, 68, 70}Zn targets of 200–400 μg/cm² on iron backings of about 1.3 mg/cm² have been prepared using a rotating substrate setup to improve target homogeneity. Using a special rolling technique, ^{64, 66, 68, 70}Zn and ^{110, 114, 116}Cd have also been rolled to thin foils.