玻璃表面的无钯活化化学镀镍

在非金属基体上化学镀镍 ,一般要先在基体上形成一层化学镀的催化剂 ,传统工艺是采用PdCl2 SnCl2 活化 敏化法[1 ] 。该工艺处理过程复杂 ,而且使用有毒的PdCl2 ,其价格昂贵。因此无钯活化法将带来巨大的经济效益和社会效益。我们曾在这方面进行了有益的尝试 ,如将玻璃表面经喷雾热解形成ZnO ,然后吸附银盐 ,活化还原 ,再化学镀[2 ] 。李兵等[3] 研究了非金属材料无钯催化活化工艺。研究了活化时间及温度对覆盖度的影响 ,但未给出具体活化液配方。本文提出了玻璃表面的一种无钯活化镀镍液配方 ,该配方由醋酸镍、甲醇、柠檬酸钠和氨组…     

低温低内应力化学镀镍工艺的研究

化学镀广泛应用于非金属的电镀、电铸前的施加导电层。化学镀沉积层质量与其在零件上的附着力有着密切的关系 ,重视对化学镀沉积层内应力的研究 ,开发一个低温、低内应力的化学镀镍工艺 ,对于化学镀沉积层的推广应用有着十分重要的意义。本文采用正交实验方法对低温、低内应力化学镀镍工艺进行了系统研究 ,开发出了一个低温、低内应力的化学镀镍工艺。在实验过程中发现沉积层内应力同其在零件上的结合力具有密切关系并对其进行了初步探讨。1　实验方法1 1　正交实验根据探索性实验结果分析 ,影响化学镀镍层内应力σ和沉积层速率ｒ的主要因…     

碳纳米管表面的无钯活化化学镀镍研究

本文提出碳纳米管表面无钯活化的化学镀镍方法.碳纳米管经硝酸氧化和碱中和后表面生成羧基,利用羧基吸附镍离子,之后吸附的镍离子被化学还原为镍的纳米微粒并成为化学镀镍的催化活性中心.红外吸收光谱和电子显微镜观察等证实了上述活化过程的机理.实验表明,新的活化方法对碳纳米管表面化学镀是切实可行的,文中同时对化学沉积层的不同形貌进行讨论.     

化学镀镍法制备碳纳米管

以PdCl2为活化液,用化学镀镍法制备了具有活性中心的镀镍硅模板,通过催化裂解在镀镍硅模板上制备了碳纳米管。讨论了化学镀工艺参数对镀镍硅模板表面活性中心的尺寸和分布的影响。最佳的工艺条件为:在0.17mol·L-1的SnCl2中敏化10min,0.4g·L-1PdCl2中活化2min,50℃施镀3min所得的镍粒子活性中心的粒径为200nm~300nm。用扫描电镜观察到碳纳米管为竹节形状,直径为100nm~110nm。     

化学镀镍诱发过程的研究 Ⅰ.金属催化活性的鉴别和反应机理

某些金属可以自发进行化学镀镍反应,它们称为“催化活性”金属;而另一些金属必须用“催化活性”金属诱发后才能进行化学镀镍反应。本文用测定稳定电位和稳定电位-时间曲线的方法确定:(1)金属的稳定电位可以作为鉴别金属有无“催化活性”的物理量。在80℃的HEDP化学镀镍液中,稳定电位负于-0.6V者有活性,正者则无。(2)诱发反应的有效性可从基体金属的稳定电位-时间曲线看出。(3)化学镀镍层的稳定电位为-0.72V,它本身具有“催化活性”,基体金属沉积上镍磷镀层后即可连续反应,若无此镍磷镀层,“催化金属”脱离接触后,稳定电位迅即回复为基体金属原来的电位。(4)稳定电位正的金属可用稳定电位负的“催化金属”诱发。诱发时两金属必须在溶液中接触或用外接导线连结。诱发HEDP化学镀镍反应必须同时满足基体金属的稳定电位负于-0.60 V和反应温度高于50℃。(5)诱发反应的机理可用两种金属在溶液中形成化学电池来解释。“催化金属”溶解时释放出的电子通过导线或短路电路流向基体金属,使它的稳定电位迅速负移,并使镍配离子和H~ 在它上面放电,析出镍和氢,再进一步促使次亚磷酸钠还原为元素磷,并与镍形成镍磷合金。     

自组装技术在电磁屏蔽织物加工中的应用

尼龙织物经功能性高分子壳聚糖(CS)预处理后,应用分子自组装技术于其表面自组装钯膜(镀镍前活化).该膜钯微粒为纳米级,比表面较大,催化活性较高.将成膜后的织物化学镀镍磷合金,即可得到屏蔽性能优异的电磁屏蔽织物.正交试验及单因素试验得出CS预处理的最佳工艺条件.SPM、SEM表征活化前后及施镀前后织物表面的形态变化.根据Schelkunoff理论,计算织物的电磁辐射屏蔽效能,其值高于30 dB,相当于屏蔽掉了96.0%以上的电磁波.     

酸性化学镀镍磷合金的动力学机理

通过极化曲线研究了3种不同溶液（阴极液、阳极液和完整镀液）的电化学行为,测定了主盐、还原剂浓度以及镀液pH和体系温度对化学镀镍沉积速率的影响. 与直接在镁合金上化学镀镍并使用重量分析法得到的沉积速率相比较发现,完整镀液体系的极化曲线才能真实地反映化学镀镍的沉积过程,其过程不能简单视为由彼此完全独立毫无关联的阴阳极半反应构成. 根据Butler-Volmer公式,本化学镀液体系的化学镀镍过程属混合控制,其表观反应活化能为42.89 kJ·mol^-1.     

钨的化学机械抛光过程中TiN-W电偶的腐蚀行为(英文)

化学机械抛光 (CMP)技术是同时利用化学和机械作用来获得固体表面亚微米尺度上平整性非常有效的方法 ,从 90年代初期起已成为制备高质量镜头和镜面及集成电路制造过程中硅片表面预处理工艺中最常用的技术之一 .钨的化学机械抛光是用钨坯获得硅片球面平整度的重要工艺 .其过程实际上是先将钨沉积到硅上已有的薄粘附层 -氮化钛上 ,然后进行化学机械抛光 .当抛光阶段接近终了时 ,氮化钛和钨表面将同时暴露在化学抛光液中形成电偶对 ,并在界面上发生腐蚀行为 ,从而影响硅片的球面平整度 ,降低半导体器件的性能与可靠性 .本文通过采用电化学直流极化技术 ,分别获得钨与氮化钛在 0 .0 1mol/LKNO3溶液中或含有三种典型的研磨剂 (H2 O2 ,KIO3,Fe(NO3) 3)溶液中的极化曲线 ,同时设计了一种特殊的电解槽以测量钨和氮化钛之间相互作用的电流 ,初步研究了 patterned硅片上钨和氮化钛界面形成电偶对时的腐蚀行为 .根据所测的钨和氮化钛电位可知 ,当钨和氮化钛表面同时暴露在抛光液中时将形成电偶对 ,氮化钛成为阴极 ,钨为阳极 ,并于界面发生电化学反应 ,表面的不均匀腐蚀将造成硅片平整度的降低 .结果表明 ,当溶液中含有H2 O2 时钨和氮化钛界面的腐蚀速度最大 ,而当溶液中含有Fe(NO3) 3时的钨和氮化钛界面则几乎不发     

电镀非晶态镍磷合金在织物上的应用

制备了一种镍磷非晶态合金电磁屏蔽材料,并对制备工艺及其性能进行了初步的研究与探讨,选择了一条较为成功的工艺流程.选用已化学镀铜导电涤纶织物,经过电镀处理,得到稳定、光亮的非晶态镍磷镀层.利用正交试验方法,研究了镀液组成、温度、时间、pH值等对镀层的K/S值与电阻值的影响,优选出了最高K/S值和最低电阻值的工艺条件,分析了各因素对电沉积过程的影响.得出工艺条件:硫酸镍250g/L、氯化镍55 g/L、次亚磷酸钠70g/L、硼酸45 g/L、时间10 min、温度65℃、pH=2.0.实验表明,此电镀镍磷非晶态合金柔性电磁屏蔽材料具有良好的导电性能及耐磨擦、耐腐蚀性能.     

化学镀镍磷镀层及其耐蚀性研究

针对工业实际对提高防护层防腐、耐磨性能的要求,对化学镀镍磷镀层的方法,镀敷液配方等进行了分析,对其腐蚀率进行了测定,并对镀层性能进行了表征;讨论了影响腐蚀率的若干重要因素;对有关工艺进行了优化,从而在多种基质上获得了抗腐蚀性较好的镍磷镀层,初步研究证明,其性能优于电镀方法所获得的镀层.     

Effect of 3-Amino-5-mercapto-1,2,4-triazole on Electroless Nickel Deposition

The effects of organic additive, 3-amino-5-mercapto-1,2,4-triazole （AMTA） on bath stability, deposition rate, reaction activation energy, and Ni-P coating composition in acidic electroless nickel plating were investigated. Polarization curve method and infrared reflection spectroscopy were used to analyze the mechanism of the effect of AMTA on electroless nickel deposition. It was observed that AMTA improved bath stability, decreased the deposition rate, and increased the reaction activation energy. It was also revealed that AMTA decreased the phosphorus content and increased the sulfur content in Ni-P coating. In addition, AMTA inhibited the anodic oxidation of hypophosphite and accelerated the cathodic reduction of Ni^2＋. Infrared reflection spectroscopy result indicates that AMTA was adsorbed on the surface of Ni-P and interacted with Ni^2＋ to form an AMTA-Ni^2＋ compound. On the basis of the results of this study, the mechanism of the effect of AMTA on electroless nickel deposition was deduced.     

Effect of 3-S isothiuronium propyl sulfonate on electroless nickel deposition

The effects of organic additive, 3-S isothiuronium propyl sulfonate (UPS) on bath stability, deposition rate, reaction activation energy, and Ni-P coating composition in acidic electroless nickel (EN) plating were investigated. The study was performed by measuring the polarization curves and X-ray fluorescence spectrometer (XRF) in combination with X-ray photoelectron spectroscopy (XPS) analysis. The results show that UPS improves bath stability and increases the reaction activation energy. At lower concentration, UPS is an effective accelerator for EN deposition; whereas, at higher concentration, it decreases deposition rate. It also reveals that UPS inhibits the anodic oxidation of hypophosphite and accelerates the cathodic reduction. In addition, UPS decreases the phosphorus content in Ni-P deposit and can be adsorbed on the deposit surface and compound with Ni²⁺. On the basis of these results, the effect mechanism of UPS on electroless nickel deposition was deduced.     

Ni-P-TiO2化学复合镀层电极的乙醇电催化氧化

于Ni-P镀液添加TiO2颗粒,用化学镀法在黄铜基底上制备不同TiO2含量的Ni-P-TiO2复合镀层电极.采用循环伏安法、线性扫描法、计时电流和交流阻抗法测定Ni-P-TiO2/Cu电极的电化学性能.结果表明:常温下Ni-P-TiO2/Cu电极在碱性溶液中对乙醇氧化有很高的电催化活性;Ni-P-TiO2电极上乙醇的电催化氧化活性随镀层TiO2量的不同而异;镀液中TiO2含量为5 g.L-1时,所得电极的电催化乙醇氧化的活性最佳.     

Optimization of zinc phosphate coating on 7075-T6 aluminum alloy

A zinc phosphate coating process on 7075-T6 aluminum alloy has been significantly improved through a combined approach of titanium colloid pretreatment, pH level adjustment, fluoride additive and ZnO/H₃PO₄ ratio adjustment. In particular, optimum phosphate coatings were formed in coating baths with a ZnO/H₃PO₄ ratio of 0.205 and 0.256. Coating morphology studied by SEM reveals that the adjustment in the coating procedure produces an improved crystalline coating layer with high coverage and small grain size. For coatings formed in a bath with a ratio of 0.205, the coverage of the crystalline patches on top of the amorphous coating base is almost complete. The chemical composition of the coating layers has been characterized by XPS and SIMS. The crystalline and amorphous coating phases formed in the bath with a ratio of 0.205 were found to have compositions given schematically as Zn_x(PO₄) and Zn_xAl_y(PO₄), respectively. In contrast, neither coating phase formed in the bath with a ratio of 0.256 shows the presence of Al.     

Electrochemical characteristics and interfacial contact resistance of Ni-P/TiN/PTFE coatings on Ti bipolar plates

The Ni-P/TiN/PTFE (poly tetra fluoroethylene) composite coatings were prepared by electroless plating method on Ti plate, which was used as bipolar plates of proton exchange membrane fuel cells (PEMFCs). The morphology, crystallographic texture, electrochemical corrosion, contact resistance, and hydrophobic property of the Ti bipolar plates with coatings were investigated. The results revealed that Ni-P/TiN/PTFE coating had a dense surface morphology, uniform distribution of composite particles. Ti with coating showed 0.48 μA cm² of corrosion current in the simulated solution of PEMFCs and 6 mΩ cm² of interfacial contact resistance (ICR). The hydrophobicity test showed that the coating interface was flat and the wetting angle was 112.4°. In conclusion, The Ni-P/TiN/PTFE composite coatings exhibit superior improvement in corrosion resistance, interface hydrophobicity, and conductivity to Ni-P, Ni-P/TiN, and Ni-P/PTFE coatings. The Ni-P/TiN/PTFE coating was suited for bipolar plate surface modification of bipolar plates.     

Microstructure and corrosion behavior of electroless deposited Ni-P/CeO2 coating

Electroless Ni-P/nano-CeO2 composite coating was prepared in acidic condition, and its microstructure and corrosive property were compared with its CeO2-free counterpart. Scanning electronic microscopy （SEM） and X-ray diffraction （XRD） spectrometer were used to examine surface morphology and structure of the as-plated coating. Differential scanning calorimeter （DSC） and transmission electronic microscopy （TEM） were used to study the coating＇s phase change at high temperature. The coating＇s corrosive behavior in 3%NaCl ＋ 5%H2SO4 solution was also investigated. The results showed that Ni-P coating had partial amorphous structure mixed with nano-crystals, while the Ni-P/CeO2 coating had perfect amorphous structure. In high-temperature condition, Ni3P precipitation and Ni crystallization took place in both coatings but at different temperatures, while the Ni-P/CeO2 coating had sintered phase of NiCe2O4 spinels. The anti-corrosion property was better in the CeO2-containing coating, and this was due to its less liability to undergo local-cell corrosion than its CeO2-free counterpart. Ni-P/CeO2 coating＇s pure amorphous structure was the result of Ni＇s hindered crystal-typed deposition and P＇s promoted deposition.     

化学沉积法制备Ni-P纳米线与纳米管有序阵列

以多孔氧化铝膜为模板, 在室温下的酸性化学镀镍槽中通过化学沉积法生长出纳米线与纳米管有序阵列. 分别用X射线衍射仪(XRD)与透射电子显微镜(TEM)对纳米线、纳米管阵列进行表征. 并通过对纳米线与纳米管的生长方式进行分析比较, 系统地研究了多孔氧化铝模板的前处理对纳米阵列生长的影响. 结果表明, 生成的纳米线与纳米管均为非晶态的镍磷合金. 室温下镍纳米管的生成主要取决于敏化、活化过程, 而当纳米管的厚度达到一定程度后就不再随时间变化.     

电沉积多孔复合Ni-P/LaNi5电极及其析氢电催化性能

采用复合电沉积制备了Ni-P/(LaNi₅+Al) 复合镀层, 然后将镀层浸泡在浓碱液中除铝, 成功得到多孔复合Ni-P/LaNi₅电极. 通过扫描电镜(SEM)、能谱分析(EDS)和X射线衍射(XRD)仪等技术表征了电极的表面形貌、组成和相结构. 运用电化学线性伏安扫描(LSV)、恒电位电解、电化学阻抗谱(EIS)等手段研究了电极在20%(w) NaOH溶液中的析氢反应(HER)电催化性和稳定性. 结果表明, 与多孔Ni-P 电极相比, 多孔复合Ni-P/LaNi₅电极具有低的析氢过电位、高的比表面积和高的稳定性能; 多孔Ni-P/LaNi₅电极的析氢反应的表观活化自由能为35.44 kJ·mol^-1, 低于多孔Ni-P 的值(50.91 kJ·mol^-1).     

On the formation of the interlayer between Ni-P coating and AZ33 magnesium alloy substrate by means of in situ SEM observation

Pre-treatment process is the key step for electroless plating. Once a suitable pre-treatment film is in place, the desired metals can be plated. In this paper, Ni-P coating was successfully prepared on AZ33 magnesium alloy with Mg（OH）2 pre-treatment film by electroless plating. To investigate the role of MgF2 in Ni-P coating, the deposition procedures between Mg（OH）2 pre-treatment film and Mg（OH）2-MgF2 pre-treatment film （a traditional process） were compared. The surface morphology variations of coatings were observed with scanning electron microscopy and the compositions were analyzed by energy dispersive spectrometry. The results showed that during the plating, both MgF2 and Ni-P deposited at the initial stage, and MgF2 distributed in the bottom of the coating, forming a transitional interlayer with Ni- P. According to the heat quench test, a poor adhesion of the coating mainly occurred between the MgF2 and Ni-P coating.     

稀土对电沉积Ni-P合金镀层耐蚀性的影响

研究了稀土对电沉积Ｎｉ－Ｐ合金度层耐蚀性及组织的影响,通过浸泡实验和极化曲线的测定。得出在镀液中添加一定量的稀土元素能显著改善镀层的耐蚀性能。ＸＲＤ,ＴＥＭ,ＥＤＳ结果表明,稀土元素具有促进Ｎｉ－Ｐ合金形成非晶组织的作用,由于稀土的加入,在远低于８％的Ｐ含量下,获得了以非晶态为主的组织。