热镀锌钢板表面状况对漆膜性能的影响

热浸镀锌钢板表面粗糙度、无铬耐指纹钝化后锌层的均匀性及锌渣等表面状况直接影响着镀锌钢板漆膜层的各项性能;热浸镀锌钢板表面的粗糙度对钝化膜的性能有影响,进而影响耐指纹热镀锌钢板的涂漆附着力和耐蚀性能.采用SEM,EDS,EPMA等方法,对耐指纹热镀锌钢板进行分析,找出了漆膜性能与镀锌钢板表面粗糙度之间的关系,发现锌层的不...     

模拟拉延筋的镀锌薄钢板锌层粘附性试验方法的研究

基于现有拉延筋试验机，结合汽车厂冲压实际，研制、开发了测定镀锌钢板锌层粘附性的模拟拉延筋的模具，研究了试验条件对试验结果的影响。在此基础上，制定了镀锌钢板锌层粘附性试验规范，并对常用镀锌钢板的锌层粘附性进行了测定，为镀锌钢板的研究和在汽车上的应用提供了依据。     

进口彩涂钢板失效分析

借助扫描电镜(SEM)和能谱分析(EDAX)等分析手段,对彩涂钢板镀锌层的均匀性、基板进行了研究.结果表明,本批彩涂钢板的基板存在镀锌不均以及锌层严重氧化等质量问题,是导致整批彩涂钢板发生表面油漆剥离,并造成部分钢卷加工成型的构件失效的主要原因.     

电镀锌阳极的选用

我厂在锌酸盐镀锌和酸性镀锌工艺生产中 ,一直选用 1号锌锭 ,用铁锅熔融后浇铸成 70 0ｍｍ× 80ｍｍ× 4 0ｍｍ块状的锌阳极板。但经过长期的生产使用表明 ,采用这种自浇铸的锌阳极板存在以下不足 :(1)质量差　因自浇铸锌阳极板的工艺技术和铸造条件不具备而导致浇铸的锌阳极表面粗糙不均、局部杂夹着含熔渣的硬氧化层 ;温度的变化使结晶粗细不匀 ;出现冷纹 ,造成使用过程中锌阳极板的化学溶解和电化学溶解加快、锌阳极板的溶解断裂。(2 )易使电镀锌零件表面附着有锌的粗粒子　当锌阳极板挂入碱性镀液中后 ,即使通电 ,一方面发生锌阳极的化…     

合金化热镀锌无间隙原子钢板表面白色点状压印缺陷的产生原因

使用扫描电子显微镜、能谱仪、光学显微镜等设备，对合金化热镀锌无间隙原子钢板表面白色点状压印缺陷进行分析，查明了该缺陷的产生原因。结果表明：该缺陷表面合金化不充分，平整印较多，锌层局部偏厚，部分溶锌后发现有氧化铁皮；钢板表面氧化铁皮局部偏厚，酸洗时氧化铁皮未能被完全溶解，并压在钢板表面，镀锌合金化后呈白色点状压印形貌。采用降低卷取温度的方法，可有效减小钢板表面氧化铁皮的厚度，后续钢板未再发现该类缺陷。     

镀锌钢板点焊参数对熔核结晶形态的影响

分析和比较了普通冷轧钢板、电镀锌钢板和两种锌层厚度不同的热镀锌钢板在几种点焊参数下的熔核结晶形态。结果表明：镀锌层的存在对点焊熔核结晶形态很不利，增加焊接时间和焊接压力能使熔核结晶形态有所改善，但增加焊接电流会对其更不利。根据试验结果，对镀锌钢板点焊参数选择提出了建议。     

冷金属过渡条件下AZ61镁合金在两种钢板上的润湿行为

采用动态座滴法研究冷金属过渡条件下,AZ61镁合金分别在Q235钢板和镀锌钢板表面的润湿行为及其界面微观结构。结果表明:润湿行为与焊接工艺参数中的送丝速率密切相关;无论基板采用镀锌钢还是Q235钢在界面处均观察到Al-Fe金属间化合物层,其形成符合热力学形成条件;在Q235钢表面润湿时,送丝速率增加,界面反应变得剧烈,因而润湿性变好,在镀锌钢表面润湿时,送丝速率增加,加剧锌的挥发,使裸露的表面显金属性,因而润湿性变好;当送丝速率≤10.5m·min~(-1)时,镁在Q235钢板上的润湿性要好于镀锌钢板,且后者锌的挥发将导致工艺不稳定。     

快速测定热浸镀锌钢铁上的锌量

利用乌洛托品对钢铁在酸性介质中产生缓蚀效应，阻止铁基的溶介，在６ｍｏｌ／Ｌ ＨＣｌ中将热浸镀钢铁材料上的锌层溶解，称量退镀前后重量，求得镀锌量及锌层厚度。     

金属包装的涂层钢板及其涂料探密

正涂层钢板具有轻质、雅观和杰出的防腐化机能,又可直接加工,它给包装业、建筑业、造船业、车辆制造业、家具行业、电气行业等供给了一种新型原材料,起到了以钢代木、高效施工、节俭能源、防止污染等效果。利用镀锌钢板为基板的涂层钢板,锌层上的有机涂层起到隔离作用,可防止钢板生锈,使用寿命比镀锌钢板更长,因此广受消费者欢迎。     

铝合金与镀锌钢薄板熔钎焊接头组织与力学性能

为了对铝合金和镀锌钢板进行优质高效焊接,采用Fronius冷金属过渡焊接机对锻铝6061和SPCC镀锌钢板进行了熔钎焊实验。焊接实验结果表明可以采用专家系统提供的参数进行焊接获得成型良好的接头;组织分析表明接头界面可以分为边缘富锌区、铝熔化区和铝钢界面反应层三个反应区。能谱分析结果表明边缘富锌区主要组成元素是锌和铝,铝钢之间的反应层主要是Fe2Al5反应相;接头上的缺陷主要有气孔、冷隔和低熔共晶缩孔。力学性能测试结果表明:铝、钢熔钎焊接头强度达到80MPa;Fe2Al5反应相平均硬度HV410,镀锌钢母材的平均显微硬度HV130,铝熔化区的平均显微硬度HV55。     

X-ray photoelectron spectroscopy and corrosion studies of zinc phosphate coated on 7075-T6 aluminium alloy

Coated layers which formed on 7075-T6 aluminium alloy surfaces after treatment in zinc phosphate (ZPO) suspensions adjusted to different pH values (3.5, 5.0, 6.6, 10.5 and 13.0) were characterized by X-ray photoelectron spectroscopy (XPS). Comparative XPS tests were also made after the treated surfaces were exposed to a 3.5% NaCl solution for 5 h. The processes of coating from solution, oxidation, etching and bulk diffusion were all involved, although in different proportions, in the different treatments. The amounts of zinc and phosphorus in the uppermost layers were enhanced when the coating was at pH values of 5.0, 10.5 and 13.0, and in each case a mixed ZnO _x -AlO _x -ZPO structure was apparently formed. The coating prepared at pH=13.0 appeared to provide the best corrosion protection.     

Dissolution kinetics of MgO crystals in aqueous acidic salt solutions

The revelation and morphology of dislocation etch pits as well as the rates of macroscopic dissolution and selective etching on the {1 0 0} plane of MgO crystals in aqueous solutions of various inorganic salts are investigated in relation to the nature and concentration of salt in solution and the etching temperature. It is found that addition of a salt generally facilitates etch pit formation and that the rates of surface dissolution and selective etching increase with additive concentration, etchant temperature and character and ageing of dislocations, while the etch pit morphology depends on the concentration and chemical nature of an impurity, etching temperature and the ageing of the dislocations. It is also observed that some fast etching solutions produce very shallow etch pits at screw dislocations. The results are discussed from a consideration of solution pH, standard electrode potentials of metals and stability of complexes present in solution. The importance of the surface entropy factor in revealing etch pits at screw dislocations is pointed out.     

铝合金锌系磷化膜防护失效机理探讨

为加深对磷化膜防护失效机理的认识,采用电化学方法和扫描电镜(SEM)考察了铝合金锌系磷化膜在不同溶液中的腐蚀与防护特性.结果表明:磷化膜的活性溶解出现在酸性和中性溶液里;钝化出现在碱性溶液里.磷化膜的防护性能主要依靠于其机械屏障作用,化学溶解是磷化膜防护失效的主要形式.     

Formation of zinc phosphate coatings on AA6061 aluminum alloy

Conditions for forming zinc phosphate conversion coatings on AA6061 aluminum alloy have been investigated by characterizing coatings formed for different parameters of the coating bath. Morphological and compositional information on the coatings was assessed by SEM, EDX and XPS, and simple adhesion tests were undertaken to indicate the strengths of coating attachment. The emphasis was to identify conditions that give high coverage, uniform coatings of small, strongly adhered, zinc phosphate crystals. The use of low-zinc solutions (e.g. an atomic Zn/P ratio of 0.07) and normal-zinc solutions (Zn/P ratio 0.25) were compared; coatings formed by the two solution types appear comparable at pH 2, although at pH 4 the low-zinc solution is more effective. Fluoride in the concentration range 200–400 ppm is indicated to be a useful additive for the normal-zinc coating bath and in the 600–1000 ppm range for the low-zinc process. The use of acid etching in the pre-treatment appears to yield better coatings than when mechanical polishing alone is used.     

稀土铈对镀锌层三价铬彩色钝化膜的影响

为了提高镀锌层三价铬彩色钝化膜的性能,通过单因素试验和对比分析的方法研究了稀土铈盐对三价铬彩色钝化膜的影响。研究发现在三价铬彩色钝化液中添加硫酸铈1.5 g/L时,钝化膜的表面质量及耐腐蚀性能最好。对比三价铬钝化膜及含铈三价铬钝化膜的外观颜色,发现稀土铈盐的添加加深了彩色钝化膜的色泽,提高了钝化膜的亮度及均匀性。从金相显微镜和扫描电镜(SEM)分析可知,2种钝化膜膜层明显,且含铈钝化膜的表面致密度更高。通过能谱仪(EDS)分析可知,稀土铈元素参与了成膜过程。黏着力测试和电化学测试表明,含铈三价铬钝化膜有较好的耐磨性和耐蚀性。初步分析镀锌层三价铬彩色钝化膜的成膜过程可知,成膜反应和溶解膜反应形成了一个动态平衡过程,通过控制钝化浸渍时间和钝化液的p H值,控制钝化膜的溶解,可以提高钝化膜的致密性。     

The effect of alkaline etching time on the anticorrosion performance of vanadia film formed on high strength AA2024 in chloride media

Corrosion performance, morphology, and electrochemical characteristics of vanadia-based conversion coatings on high strength aluminum AA2024-T3 alloy were examined as a function of alkaline etching time prior to vanadia treatment. Corrosion resistance and coating performance improved after etching in an alkaline solution for 10 min followed by vanadia treatment at room temperature. Electrochemical impedance spectroscopy and polarization testing correlated to macro- and microscopic surface examination and visual inspection. Proper etching of aluminum AA2024-T3 panels in alkaline solution prior to vanadia coating is a time dependent and considers a critical step for improved coating performance and materials durability. Results showed that the optimum alkaline etching time prior to vanadia treatment was 10 min which offers the best resistance to localized corrosion attack in NaCl solution. Alkaline etching for 10 min has an important role in increasing the number of OH groups on the aluminum surface, contributing to the adhesion of the vanadia-rich aluminum oxide layer by promoting covalent bonding. Based on these results, processes active during alkaline etching are kinetically dependent and strongly influenced by etching time.     

中低温磷化工艺及其效果

目前,许多常温磷化液化学成分复杂,磷化温度范围窄,磷化膜质量不高.为此,研究了一种中低温磷化技术,主要成分及工艺参数:30～45 g/L磷酸二氢锌,90～120 g/L硝酸锌,10～20 g/L硝酸锰,3～6 g/L硝酸镍;总酸80～90点,游离酸2～3点,用氧化锌调节;磷化温度30～70℃,时间15 min.结果表明...     

锌粉特性对机械镀锌层性能的影响

通过OLYMPUS-GX51型光学显微镜进行机械镀层金相组织检测和厚度测量、划线和划格试验及按GB/T 3091-2001 要求的硫酸铜溶液腐蚀试验,研究了锌粉粒度及形状对机械镀锌层性能的影响.试验表明:在相同机械镀锌工艺规范下,320目颗粒状锌粉镀层颗粒粗大且不均匀,厚度范围33～55 mm,500目颗粒状锌粉镀层不及500目片状锌粉镀层致密,厚度范围45～58 mm,500目片状锌粉镀层最致密颗粒分布也最均匀,厚度范围33～41 mm; 320目颗粒状锌粉、500目颗粒状锌粉、500目片状锌粉机械镀锌层与钢铁基体之间附着强度均达到有关国家标准;均匀性均达到GB/T 3091-2001要求;锌粉粒度越小对应其镀层耐蚀性及均匀性也越好;在相同粒度尺寸下(500目锌粉),片状锌粉比粒状锌粉的镀层具有更好的耐腐性.     

Chemical stability and antimicrobial activity of plasma sprayed bioactive Ca<Subscript>2</Subscript>ZnSi<Subscript>2</Subscript>O<Subscript>7</Subscript> coating

Calcium silicate ceramic coatings have received considerable attention in recent years due to their excellent bioactivity and bonding strength. However, their high dissolution rates limit their practical applications. In this study, zinc incorporated calcium silicate based ceramic Ca₂ZnSi₂O₇ coating was prepared on Ti-6Al-4V substrate via plasma spraying technology aiming to achieve higher chemical stability and additional antibacterial activity. Chemical stability of the coating was assessed by monitoring mass loss and ion release of the coating after immersion in the Tris–HCl buffer solution and examining pH value variation of the solution. Results showed that the chemical stability of zinc incorporated coating was improved significantly. Antimicrobial activity of the Ca₂ZnSi₂O₇ coating was evaluated, and it was found that the coating exhibited 93% antibacterial ratio against Staphylococcus aureus. In addition, in vitro bioactivity and cytocompatibility were confirmed for the Ca₂ZnSi₂O₇ coating by simulated body fluid test, MC3T3-E1 cells adhesion investigation and cytotoxicity assay.     

Untersuchung des Sputter‐Ätzens auf die Eigenschaften von PVD‐CrN Hartstoffschichten auf Magnesium AZ91hp

Investigating the Influence of the Sputter Etching Process on the Properties of PVD‐CrN Coatings on Magnesium Die Cast Alloy AZ91hp A common method prior to the PVD deposition is the sputter etching process of the substrate itself to clean the surface from adhesion products and to improve the coating adhesion. This report deals with the sputter etching of magnesium die cast alloy AZ91hp to investigate the influences on the coating‐substrate interface, the surface properties and the mechanical properties of PVD‐CrN hard coatings. The coating‐substrate interface of the Cr‐AZ91 coating systems was investigated with XPS and SIMS. Surface studies were carried out by high resolution electron microscopy and AFM. The characterization of the mechanical properties of the CrN‐AZ91 compound systems includes thickness, coating hardness and hardness depth profiles, coating adhesion, structure and residual stresses. Some properties show a strong dependency of the etching time, especially the mechanical properties and the coating roughness. Increasing etching times lead to an improvement of the coating quality.