共查询到19条相似文献,搜索用时 421 毫秒
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采用循环伏安法研究了氯化物体系中锌-钴合金电镀的电沉积过程,采用X-射线厚度和成分分析仪测量了锌-钴合金镀层的厚度和钴金属质量分数.试验表明,在氯化钾锌-钴合金电镀槽液可以电镀钴质量分数为0.2%~0.4%的锌-钴合金,钴添加剂的加入,能够使氢的析出电位负移,扩大了锌-钴合金沉积的电位区间范围. 相似文献
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采用脉冲电沉积法在Q235钢表面制备了Ni-Sn-Mn合金镀层,并研究了糖精钠的质量浓度对镀层的成分、沉积速率、表面形貌及耐蚀性的影响。结果表明:随着糖精钠的质量浓度的增加,阴极极化曲线负移,阴极极化作用增强;镀层中Ni和Sn的质量分数降低,而Mn的质量分数升高;沉积速率和阴极电流效率均减小;镀层的耐蚀性先增强后减弱。当糖精钠的质量浓度为3g/L时,制备的Ni-Sn-Mn合金镀层均匀致密,在3.5%的NaCl溶液中具有最正的自腐蚀电位、最低的自腐蚀电流密度和最大的电荷转移电阻,耐蚀性最好。 相似文献
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采用直流(DC)、脉冲(PC)和超声脉冲(UPC)电沉积方式在Q235钢表面制备Ni-Sn-Mn合金镀层,利用扫描电子显微镜(SEM)、辉光放电光谱仪(GDS)、X射线衍射仪(XRD)、Tafel曲线和电化学阻抗谱(EIS)研究了不同电沉积方式对镀层表面形貌、元素含量、沉积速率、相结构和耐蚀性的影响。结果表明,分别采用直流、脉冲、超声脉冲电沉积方式制备的镀层,Ni和Sn质量分数依次减小,Mn质量分数依次增大,沉积速率依次提高;直流电沉积镀层晶粒粗大,存在裂纹和孔隙,耐蚀性较差;脉冲电沉积镀层晶粒细化,无明显缺陷,耐蚀性较高;超声脉冲电沉积镀层均匀致密,呈非晶结构,在3.5%Na Cl溶液中具有最正的自腐蚀电位(-0.346 V)、最低的自腐蚀电流密度(3.162×10~(-8)A/cm~2)和最大的电荷转移电阻(9 143Ω·cm~2),镀层耐蚀性最好。 相似文献
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The electrodeposition of Zn-Co alloy deposits was studied by means of pulse-plating technique. The surface morphologies of Zn-Co alloy deposits were examined using scanning electron microscopy (SEM), and an attendant energy dispersive X-ray analyser (EDA) was used to analyse the composition of Zn-Co alloy deposits. Results obtained showed that the average current density and reverse current density amongst all the variables investigated had very strong effects on the cobalt content in the Zn-Co alloy deposits. It is possible to electrodeposit Zn-Co alloy coatings with a very wide cobalt content range of 10-90 wt.% by modulating pulse parameters. Grain size, surface appearance and internal stress in the deposits were also improved significantly by introducing reverse current. 相似文献
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脉冲电镀镍及其性能的研究 总被引:3,自引:0,他引:3
采用瓦特镀镍液,研究了脉冲占空比、平均电流密度、温度对电沉积速率,镀层光亮度和镀层在w=3.5%的NaCl溶液中耐蚀性的影响.用扫描电镜研究了直流和脉冲镍镀层的表面形貌.结果表明:电沉积速率随脉冲占空比、平均电流密度及温度的增大而加快;镀层耐蚀性,光亮度随脉冲占空比增大而变差,随温度、平均电流密度的增大先变好后变差.较佳脉冲电镀条件为:平均电流密度0.75 A/dm~2,脉冲占空比5%,温度45~50 ℃,pH 2.5~3.0.X射线衍射分析结果表明,与直流镀镍相比,脉冲镍镀层在(111)晶面存在择优取向,镀层更致密,性能更好. 相似文献
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以次磷酸钠为磷元素来源,研究了磷对锌-镍合金的电化学过程、成分、表面形貌和耐蚀性的影响。实验发现:磷需要在镍表面的催化作用下才能析出,镍和磷的沉积过程属于协同效应。磷的质量分数提高,有利于增大锌-镍合金中镍的质量分数,改善锌-镍合金的耐蚀性。然而,次磷酸钠过量会使得镀液的稳定性下降,锌-镍合金表面疏松、发黑,耐蚀性变差。 相似文献
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G. Roventi 《Electrochimica acta》2006,51(13):2691-2697
Zn-Co alloy electrodeposition from chloride baths containing different Zn2+/Co2+ ratios was investigated by cyclic voltammetry and anodic linear sweep voltammetry using a Pt electrode. The peaks were attributed by means of EDX analysis, SEM and TEM observations performed on some alloys potentiostatically deposited. In the range of potential where zinc deposits underpotential, cyclic voltammetry showed a complex cathodic peak with one maximum and two shoulders, correlated with the deposition of different cobalt rich alloys. Up to four anodic peaks, two correlated with zinc oxidation from η and γ phases and two correlated with oxidation of solid solutions of zinc in cobalt, were observed. ALSV and TEM indicated that the remarkable increase in Zn content of the alloy, which occurs with a strong inhibition of the process at potentials more negative than that of the cathodic peak and more positive than the bulk deposition potential of zinc, is due to the deposition of γ phase. No inhibition of the alloy deposition process was observed with very low concentrations of zinc (<0.015 M) in the bath containing 0.19 M Co2+. 相似文献
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Alloys of Zn-Co were deposited from sulphate electrolytes containing various additives to study their influence on the anomalous behaviour of the reactions. The effects of antimony, germanium and arsenic on the Zn-Co alloy composition and structure were examined. The results showed that the composition and structure of Zn-Co alloys deposited could be dramatically changed by antimony, and to a lesser extent by germanium and arsenic. A concentration of Sb(III) as low as 5 mg dm–3 increased the cobalt content by a factor of approximately 3; however, the deposit morphology was very dendritic. Germanium additions nearly doubled the cobalt content and the morphology was somewhat improved. The effects of process parameters such as agitation and current density in the presence of the additives were also investigated. 相似文献
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研究了电流密度对镍-铁薄膜的电化学过程、成分、表面形貌、耐蚀性和磁性能的影响。通过实验发现,镍-铁薄膜的电沉积属于一种"异常共沉积"现象。低电流密度下,镍-铁薄膜中铁的质量分数较高;高电流密度下,镍-铁薄膜中镍的质量分数较高。镍-铁薄膜属于一种典型的颗粒膜层,在4A/dm2下制得的镍-铁薄膜表面致密、颗粒细致、耐蚀性较好。随着电流密度的增大,镍-铁薄膜的矫顽力逐渐升高,而比饱和磁化强度逐渐降低。 相似文献
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研究了NaF和KIO3对Q235钢表面电沉积Ni-P合金层沉积速率的影响,并通过浸泡实验考察了Ni-P合金镀层在质量分数分别为3.5%的NaCl,10%的NaOH和5%的HCl等三种溶液中的耐蚀性.结果表明:NaF并没有提高镀层的沉积速率,而加入KIO3则提高了镀层的沉积速率.同时,加入NaF或KIO3后均能明显改善Ni-P合金镀层的耐蚀性. 相似文献
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Meenu Srivastava V. K. William Grips K. S. Rajam 《Journal of Applied Electrochemistry》2008,38(5):669-677
The aim is to develop an economical composite coating with high thermal stability. Ni–Co alloys are found to possess better
thermal, physical and mechanical properties compared to Ni. Also, oxide particles as distributed phase can impart better thermal
stability. Hence, particulates of composite Yttria stabilised zirconia, a commonly used high temperature material and alumina
(YZA) were reinforced in various Ni–Co alloy matrices through electrodeposition. The influence of YZA on the microhardness,
tribology and corrosion behaviour of Ni–Co alloys with Co contents of 0 wt.%, 17 wt.%, 38 wt.% and 85 wt.% was evaluated.
Optical and Scanning Electron Microscopy (SEM) confirmed the presence of YZA particles and Energy Dispersive X-ray Analysis
(EDX) revealed the composition. Tribology testing showed that composite containing 38 wt.% Co displayed better wear resistance.
It was found from the immersion corrosion studies that Ni–17Co–YZA coating displayed improved corrosion resistance. Thermal
stability studies showed that Ni–85Co–YZA coating retained its microhardness at temperatures of 600 °C. Thus, these coatings
can be tailored for various applications by varying the cobalt content. 相似文献
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电镀不同钨合金抽油杆的耐盐水腐蚀性及力学性能 总被引:1,自引:0,他引:1
采用电沉积法,在35CrMo抽油杆表面制备了Ni-W-P和Fe-Ni-W合金镀层,研究了钨合金镀层及其热处理对抽油杆的耐蚀性和室温静态力学性能的影响.采用X射线衍射法表征了钨合金镀层及其热处理后的结构.采用失重法、阳极极化曲线测量和电化学阻抗谱,研究了电镀钨合金抽油杆在质量分数为3.5%的氯化钠水溶液中的耐蚀性.采用扫描电子显微镜分析了电镀钨合金抽油杆拉伸断裂后的断口组织形貌.结果表明:35CrMo抽油杆电镀钨合金后,其耐蚀性明显增强;热处理使镀层的耐蚀性进一步提高;各项力学性能均达到标准要求.电镀钨合金抽油杆可以应用于油田的采油设备中. 相似文献