共查询到19条相似文献,搜索用时 156 毫秒
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为丰富和发展机械镀合金化镀层沉积方法及制备工艺,在机械镀Zn-Sn合金镀层工艺过程中,采用还原沉积活化剂替代金属锡粉,在复合的活化液作用下,锌粉以吸附沉积为主,锡的添加以还原沉积为主的镀层形成环境,可以在钢铁制品表面上形成机械镀Zn-25%Sn合金镀层.镀层性能测试结果表明:由于不使用金属锡粉作为原料,镀层中无粗大锡粉颗粒;在同样的运动和冲击条件下,还原沉积工艺方法使得机械镀Zn-25%Sn合金镀层的形成过程向着致密化和平整化的方向改变,得到的镀层平整、光亮、均匀性好,同时也有利于提高有色金属的使用率,降低生产成本. 相似文献
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Fe-Mn合金镀层结合强度的研究 总被引:4,自引:1,他引:3
镀层的结合强度是修复机械零部件的关键指标,本文研究了Fe-mn合金镀前处理、施镀工艺、镀后处理等因素对镀层结合强度的影响衣其作用机理。 相似文献
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采用机械镀方法制备了锌镀层,运用X射线衍射技术分析了镀层的物相组成和锌粉颗粒的晶格参数。研究结果表明,机械镀锌层是由单质金属锌、锡和铁构成,镀层中没有辞、锡和铁之间的化合物或固溶体等合金相存在;由纳米亚晶构成的锌粉颗粒是镀层的主体,锌粉形成镀层后没有发生晶粒细化。 相似文献
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无氰高密度镀铜工艺及其在汽车轮毂中的应用 总被引:1,自引:0,他引:1
无氰碱性镀铜技术已发展多年,终因镀液不稳定、预镀层结合力不稳定等问题而不能大规模生产应用.采用无氰高密度镀铜工艺制备了SF-8639无氰高密度铜镀层,对镀液的电流效率、分散能力、覆盖能力、沉积速度以及镀层的结合力、韧性、孔隙率进行了测试,并和国外同类技术及常用的电镀预镀工艺(氰化预镀铜、预镀哑镍)进行对比.结果表明:本工艺镀液稳定,容易控制,分散能力和覆盖能力超过氰化预镀铜;镀液和镀层各项性能达到或超过进口同类无氰碱铜;镀层致密,孔隙率比进口同类无氰碱铜低,结合力好,适用于铝合金轮毂沉锌后的预镀;本工艺在实际生产中已得到了很好的应用,具有良好的发展前景. 相似文献
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主要从Ni及部分常用Ni基合金(Ni-P、Ni-W、Ni-Cr、Ni-Co等)的电沉积工艺、所得镀层组织结构及性能特点等方面,综述了不同的电沉积工艺对镀层组织结构和耐蚀性、耐磨性的影响,以及后续的处理工艺对镀层组织及性能的影响。镀液的组成、pH值及电沉积时的电流密度和温度等因素均会对电沉积的电流效率、镀层成分及组织结构造成显著影响,影响因素较为复杂,因镀液体系的不同而异。镀后热处理通常能够有效消除镀层应力,改善微观裂纹,并在一定程度上提高镀层硬度。还以Ni及其合金的电沉积机理和合金镀层的应用前景为出发点,提出了电沉积Ni基合金的未来研究方向。 相似文献
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锌粉特性对机械镀锌层性能的影响 总被引:3,自引:0,他引:3
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. 相似文献
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A.M. Al-Sabagh M.I. Abdou M.A. Migahed A.M. Fadl M.F. El-Shahat 《Advanced Powder Technology》2018,29(2):367-379
In the present work, Egyptian ilmenite nanoparticles (FeTiO3 NPs) were obtained with the average diameters of 20?nm by a direct solid-phase milling process and synthesized amorphous silica powder grains were processed to prepare a novel fabricated Egyptian nanoilmenite/amorphous silica composite (ENI/AS) particles. Flaky-like nature of ENI/AS and the spherical shape of Zn-dust particles were emphasized by scanning electron microscopic (SEM) micrographs. The nano features of ENI/AS particles were confirmed by transmission electron microscope (TEM) investigation. Various alkyd-based cold galvanizing coating formulations were modified using different uniformly dispersing amounts of the processed ENI/AS particles as a modifier to form some nanocomposite coatings. The electrochemical behavior of nanocomposite modified coated steel films in oil-wells formation water solution have been studied by both potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The mechanical properties of the coated films were studied through some coating tests as cross-cut adhesion, bend and impact to assert their application efficiency. Scanning electron microscope (SEM) technique was utilized to survey the protective film formed on the carbon steel surface by these modified coatings in formation water solution. The results of this study reinforced remarkable corrosion protection properties of ENI/AS modified cold galvanizing coating. 相似文献
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根据低碳钢热镀锌原理,分析了低碳钢钢丝焊网热镀锌工艺中存在的问题,包括工艺不完善、锌液成分不合理、镀后抹拭材料及方法不当等而导致的热镀锌层质量不稳定、锌耗高.针对上述问题,提出了相应的改进方法,包括采用复合除锈剂进行酸洗除锈,强化除锈效果;以氯化锌与氯化铵比例为1.2~1.6、总浓度为12%~15%的混合溶液代替单一的氯化铵作为助镀剂;增加助镀后的烘干工序;采用无机物和珍珠岩混合材料作为抹拭剂等改进措施.通过改进与完善工艺,所得镀锌层表面光滑,焊接点处无积锌,锌耗比工艺改进前降低2%. 相似文献
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高硅铝合金浸锌溶液性能的研究 总被引:1,自引:0,他引:1
为了在高硅铝合金上获得结合力好的镀层,通过对其浸锌过程的电化学测量、浸锌和锌合金膜在人造海水中的稳定电位、浸锌层在3.5%NaCl溶液中腐蚀速率的测试以及扫描电镜对浸锌层微观形貌的观察等的研究,选出适合于高硅铝合金的镀前预处理工艺.浸锌溶液中的多元无氰配位剂,与铁离子、镍离子、铜离子形成可溶性的配位阴离子,和铝发生微量的置换反应,形成骨架同锌离子一起沉积在工件表面.首次采用拉伸试验将高硅铝合金基体与镀层之间的结合力定量化.该工艺所获得的浸锌合金层性能稳定,与镀层结合力良好,并提高了耐蚀性. 相似文献
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Erhard Broszeit 《Thin solid films》1982,95(2):133-142
By means of chemical (autocatalytic) and electrolytic codeposition of nickel and silicon carbide particles it is possible to produce coatings with enhanced wear and corrosion resistance on metallic and plastic substrates.In the first part of the paper the basic plating technique in relation to the type, form, grain size and activation of the SiC particles will be described.The mechanical properties of the coatings depend on the amount of incorporated particles in the nickel matrix. By activation of the SiC powder the content of particles in the coating can be increased significantly. Mechanical properties such as hardness, strength and elastic modulus improve with increasing content of particles. It will be further shown that the negative influence of a pure nickel coating on fatigue is reduced with a coating of NiSiC. This result can be explained by the behaviour of the internal stresses in the coating as a function of the SiC content. The tribological properties of the coatings were tested by an abrasive wear mechanism under lubricated conditions combined with corrosion. The corrosive wear tests were performed under potentiostatically controlled conditions.The high temperature application of these coatings is limited by the thermal decomposition of the SiC particles in the nickel matrix at about 500 °C. The coatings were examined by various techniques such as differential thermal analysis, X-ray diffraction and secondary ion mass spectrometry. The influence of different temperatures on the mechanical and tribological properties of the coatings will be described. 相似文献
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羰基铁/环氧有机硅树脂涂层的吸波性能和力学性能研究 总被引:4,自引:2,他引:2
采用羰基铁为吸收荆、环氧改性有机硅树脂为基体,制备了羰基铁/树脂基涂层,研究了羰基铁用量对吸波涂层的电磁和力学性能的影响.结果表明,羰基铁经过润湿分散剂处理后,粉体与树脂间的相容性得到改善,从而提高了界面结合力,因此吸波涂层整体的力学性能得到了提高.当羰基铁含量为70%(质量分数,下同)时,复合材料的附着力为22.16MPa,冲击强度大于或等于50kg·cm.采用同轴法测试了涂层材料在2~18GHz频段内的电磁参数,并对羰基铁/环氧有机硅树脂基涂层的反射系数进行了测试,结果表明,吸波涂层的最大吸收峰随吸收剂含量的增加向低频移动.涂层厚度为2mm时,羰基铁含量为65%,涂层的最大反射率在5.12GHz时达到-32.25dB;羰基铁含量为75%,在频率为3.53GHz时材料的反射率达到最大值-36.02dB. 相似文献