共查询到20条相似文献,搜索用时 62 毫秒
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采用极化曲线法和循环伏安法研究了K4P2O7·3H2O+Sn2P2O7溶液体系中Sn(II)的阴极还原反应机理和动力学规律。结果表明,焦磷酸盐溶液体系电沉积Sn的表观活化能为13~14 k J/mol,即电极过程遵循扩散控制的动力学规律。Sn2+在焦磷酸盐溶液中的主要存在形式是[Sn(P2O7)2]6-,但在阴极直接放电还原的是[Sn(P2O7)]2-,电沉积锡的可能机理为:[Sn(P2O7)2]6-[Sn(P2O7)]2-+42 7P O-;[Sn(P2O7)]2-+2e-→Sn+42 7P O-。 相似文献
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以HEDTA(N-β-羟乙基乙二胺三乙酸)为主配位剂,通过极化曲线测量、电感耦合等离子体发射光谱、表面形貌分析和X射线衍射谱分析等研究了pH对Sn-Ag-Cu三元合金共沉积的影响。镀液组成及工艺参数为:Sn(CH3SO3)2110g/L,Ag2O0.0811g/L,Cu(CH3SO3)20.876g/L,HEDTA278.3g/L,硫脲4.6g/L,烷基糖苷1g/L,温度25°C,电流密度10mA/cm2。结果表明,随pH增大,Sn-Ag-Cu的沉积电位负移。pH为3.22~7.74时,Sn-Ag-Cu合金镀层结晶细致、表面平整。Sn-Ag-Cu合金镀层由Sn、Ag3Sn和Cu6Sn5组成,其结晶取向随pH改变而变。HEDTA体系电沉积Sn-Ag-Cu合金镀层的适宜pH为3.00~6.00,最优范围是5.00~6.00。 相似文献
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以HEDTA(Nβ羟乙基乙二胺三乙酸)为主配位剂,通过极化曲线测量、电感耦合等离子体发射光谱、表面形貌分析和X射线衍射谱分析等技术研究了甲基磺酸盐镀液中HEDTA含量对Sn-Ag-Cu三元合金共沉积的影响。镀液的基础组成和工艺条件为:Sn(CH3SO3)2 0.18mol/L,Ag2O 0.006mol/L,Cu(CH3SO3)2 0.0012mol/L,硫脲0.06mol/L,烷基糖苷(APG)1g/L,pH4.0~6.0,温度25°C,电流密度7mA/cm2,时间30min。结果表明,随镀液中HEDTA含量的增加,Sn-Ag-Cu的沉积电位负移;但n(HEDTA)∶n[Sn(II)]大于2.2∶1.0时,HEDTA才可满足一定的配位要求,使沉积电位产生足够大的负移。镀液中HEDTA含量为0.6~1.2mol/L,即n(HEDTA)∶n[Sn(II)]为(3.3~6.7)∶1.0时,HEDTA的含量对镀层组成影响不大,所得Sn-Ag-Cu合金镀层结晶细致,表面平整、均匀,主要由Sn、Ag3Sn和Cu6Sn5组成。此外,随镀液中HEDTA含量的变化,镀层的结晶取向发生变化。 相似文献
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采用直流电沉积法在高锰铝青铜基体上制得Cu-Ni合金镀层,镀液组成和工艺条件为:CuSO4·5H2O 20 g/L,NiSO4·6H2O 84 g/L,C6H5O7Na3·2H2O 75 g/L,十二烷基硫酸钠0.5 g/L,H3BO320 g/L,电流密度15~30 mA/cm^2,pH 7,温度55℃,搅拌速率300 r/min,时间60 min。研究了电流密度对Cu-Ni合金镀层元素成分、微观形貌和耐蚀性的影响。结果表明,在电流密度30 mA/cm^2下所得到的Cu-Ni合金镀层最厚,为25μm,耐蚀性最好,经乙酸盐雾试验168 h后表面仅有几个微小的腐蚀坑。 相似文献
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The effect of triethanolamine (TEA) and heliotropin (HT) on the cathodic polarization of weakly acidic baths and the properties of Sn-Ag-Cu alloy electrodeposits were investigated. Lead-free Sn-Ag-Cu solder alloy were electrodeposited in weakly acidic baths (pH 5.5) containing Sn(CH3SO3)2, AgI, Cu(CH3SO3)2, K4P2O7, KI, hydroquinone, TEA, HT and methylsulfonic acid (MSA). The cathodic polarization of baths and the properties of electrodeposits were evaluated by Liner sweep voltammetry (LSV), scanning electron microscopy (SEM), X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared spectrometer (FT-IR) and X-ray photoelectron spectroscopy (XPS). The results indicate that HT is a main brightening agent that increases the cathodic polarization of baths and refines the grains of electrodeposits; TEA is a complexing agent for copper ions and a brightening promoter that decreases the cathodic polarization of baths and densifies the electrodeposits. The bright, compact, and smooth Sn-Ag-Cu alloy electrodeposits contain 88-95 wt% tin, 5-10 wt% silver and 0.5-2 wt% copper. Organic compounds used in the baths neither adsorb on the electrodeposits surfaces nor are included in the electrodeposits. It can be therefore concluded that the use of both TEA and HT is better than that of them either in the process of electroplating bright Sn-Ag-Cu alloy. 相似文献
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采用氨基乙酸、抗坏血酸、硫脲和柠檬酸三钠4种配位体系镀液电沉积制备Cu–Cr合金。通过测定循环伏安曲线和线性扫描伏安曲线,研究了不同镀液的电化学行为。氨基乙酸体系镀液最适用于制备Cu–Cr合金,采用该配方制得的Cu–Cr合金中Cr含量高达18.63%,10A/dm2下电镀10min所得镀层厚度为25μm,表面平整,呈光亮的金黄色,结合力好,相对导电率达68.2%,导电性基本满足触头材料要求。 相似文献
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化学镀镍复合配位剂的研究 总被引:1,自引:0,他引:1
采用对比试验和正交试验,以镀速、孔隙率、镀液稳定性和镀层硬度为评价指标,研究了单一配位剂及复合配位剂对镀液和镀层性能的影响,得到了复合配位剂的最优组合:8.4g/L乳酸,6g/L苹果酸,9g/L柠檬酸,8g/L丁二酸,1g/L丙酸。采用该复合配位剂的工艺配方可提高镀液使用寿命,获得性能优良的镀层。 相似文献
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《Journal of Sulfur Chemistry》2013,34(4):391-396
We performed a theoretical analysis of the systems formed by Pb/PbS with one or two molecule(s) of triethanolamine as a complexing agent. Conformational analysis, geometry optimizations and frequency calculations at the MP2/LANL2DZ level of theory were performed to check the isomer stabilities. 相似文献