Electrochemical Study on Electroless Nickel Plating Using Sodium Borohydride as the Reductant

Corresponding author. Email: [email protected]; Tel: +86-592-2180738.[中文文摘]采用线性电位扫描伏安法研究了以硼氢化钠为还原剂的化学镀镍体系,考查了镀液组成及工艺条件对化学镀镍硼阴、阳极过程的影响,结果表明:乙酸镍和硼氢化钠含量的提高分别促进了Ni2+的还原反应和BH-4的氧化反应;乙二胺、氢氧化钠以及添加剂硫脲、糖精钠对阴、阳极反应均有不同程度的抑制作用,同时添加剂中的硫元素加速了镍的氧化;升高温度有利于阴、阳极反应的进行.[英文文摘]We studied electroless Ni-B plating with sodium borohydride as the reductant by linear sweep voltammetry.The effects of bath solution composition and operating conditions on the cathodic reduction and anodic oxidation were studied.Increases in the concentrations of nickel acetate and sodium borohydride accelerated the reduction of Ni2+ and the oxidation of BH4,respectively.Ethylenediamine,sodium hydroxide,thiourea and saccharin sodium inhibited both the cathodic and anodic reactions to varying degrees.Additionally, sulfur in the additives promoted the dissolution of nickel. High temperature was beneficial to both the cathodic reduction and anodic oxidation.国家自然科学基金(20573086)资助项

Research progress of the additives to organic electrolytes for secondary Li-ion batteries

锂蓄电池有机电解液添加剂因其有用量少且功效大等特点日益引起人们的关注,根据作用功能,添加剂主要可分为五大类:过充电保护添加剂、SEI膜优化剂、阻燃添加剂、提高电解液导电率的添加剂、控制电解液中H2O和HF含量的添加剂。综述了这些添加剂的研究现状,阐述了各类添加剂的作用机理,并对其研究方向进行了展望。Electrolyte additives used in secondary Li-ion batteries were reviewed.According to their functions,the additives can be divided into 5 types,they are:overcharge protect additives,SEI film additives,anti-combustion additives,enhancing the conductivity of the electrolyte,additives for controlling the content of acid and water in the electrolyte.The research status of these additives were overviewed,functions and mechanisms of the additives were summarized and discussed.国家“973”项目(2007CB209702

New Developing of Pretreatment Process for Electroless Plating of Ceramics

[中文文摘]综述了非金属表面化学镀前处理工艺的现状和发展,对陶瓷化学镀的粗化和活化工艺的新进展进行了评述,侧重讨论了离子型、胶体钯型、浆料型、分子自组装吸附钯型、贱金属型活化工艺特点和进展,并展望了今后发展方向。[英文文摘]The new developing of pretreatment processes for electroless plating of nonmetallic materials were reviewed, especially for the chemical roughen and activating processes of electroless plating on ceramic surface. The technical characteristics of several activating processes were discussed, and the developing of pretreatment process was prospected

Research Progress in the Fabrication of Metal Matrix Composites by Electrochemical Methods

［中文文摘］金属基复合材料具有高比强度、高比模量、高硬度、耐高温等一系列优点,在现代航空、航天及武器装备等领域具有广阔的应用前景。综述了近年来电化学方法制备金属基复合材料的研究进展,具体介绍了电化学渗浸、连续分步电沉积和复合电沉积3种不同的电化学工艺过程。［英文文摘］Metal matrix composites have excellent properties including high specific strength, modulus, hardness and heat resistance and have abroad application prospect in the production of modern aircraft and weapon. This article reviews the recent research progress in the fabrication of metal matrix composites by electrochemical methods. Three kinds of methods including electrochemical infiltration, continuous stepped electrodeposition and coelectrodeposition are introduced in detail.国家自然科学基金资助项目(20573086

FABRICATION OF HYDROXYAPATITE/ALUMINUM OXIDE COMPOSITE COATINGS BY THE COMBINATION OF ELECTROPHORETIC DEPOSITION AND REACTION BONDING PROCESS

在金属表面用电泳沉积(electrophoretic deposition,EPD)法制备羟基磷灰石(hydroxyapatite,HA)涂层的主要问题是结合强度较低。为了提高HA涂层与基体的结合强度,先采用EPD在钛表面制得羟基磷灰石/铝(hydroxyapatite/aluminum,HA/Al)复合涂层,然后采用反应结合方法(reaction bonding process)制备羟基磷灰石/氧化铝(hydroxyapatite/aluminum oxide,HA/Al2O3)复合涂层,并与相同条件下制备的HA单一涂层进行比较研究。用扫描电镜表征涂层的表面和横截面形貌。用能量散射X射线衍射(X-ray diffraction,XRD)谱分析HA/Al2O3复合涂层的化学组成。用XRD仪研究涂层的物相组成和热稳定性。通过黏结–拉伸实验测定HA涂层与基体的结合强度。结果表明:通过850℃热处理,HA/Al复合涂层中的Al粉发生氧化反应生成Al2O3,经反应结合得到HA/Al2O3复合涂层;反应结合提高了HA涂层的致密化程度且降低了基底钛表面的氧化程度;与单一HA涂层相比,HA/Al2O3复合涂层与基底间的结合强度得到明显提高。The major problem in fabricating hydroxyapatite (HA) coating on metal substrate by electrophoretic deposition is the low bonding strength between the coating and substrate. In order to improve the bonding strength,hydroxyapatite/aluminum oxide (HA/Al2O3) composite coating was fabricated on titanium substrate using the combination of electrophoretic deposition and reaction bonding process. The HA single coating was prepared in the same conditions for comparison. Scanning electronic microscope was employed to characterize the surface and cross-sectional morphologies of the as-prepared coatings. The chemical compositions of the composite coating were analyzed through energy dispersive X-ray spectroscopy. X-ray diffraction was used to study the phase com-position and thermal stability of the as-prepared coatings. The bonding strength between the coating and substrate was tested by a shear strength testing experiment. The results show that the Al in HA/Al green coating prepared by the EPD was oxidized to Al2O3,and HA/Al2O3 composite coating was obtained using the reaction bonding process by heat treatment at 850 ℃. The reaction bonding process promotes the coating's sintering densification and improves the substrate's oxidation resistance during the heat treatment. In comparison with the HA single coating,the HA/Al2O3 composite coating exhibits much higher bonding strength.国家自然科学基金(20573086);; 国家科技支撑计划(2007BAE05B04);; 厦门市科技计划(3502Z20063005)资助项

EFFECTS OF SUSPENSION POWDER CONTENT ON THE ELECTROPHORETIC DEPOSITION OF HYDROXYAPATITE COATINGS

从不同羟基磷灰石(hydroxyapatite,HA)粉体含量的悬浮液中,在钛表面电泳沉积HA涂层。采用扫描电镜、X射线衍射表征涂层的微观形貌及物相组成,通过黏结-拉伸实验测定涂层与基底的结合强度。结果表明:提高悬浮液的HA粉体含量,有助于提高电泳沉积HA涂层的致密性,改善其烧结性能,提高烧结致密化程度;HA涂层致密性的提高,有效地抑制了钛基底表面氧化反应,改善了涂层与基底的界面结合状态,使HA涂层与钛基底的结合强度从悬浮液HA粉体含量为5 g/L时的4.54 MPa,提高到悬浮液HA粉体含量为20 g/L时的19.92 MPa。Hydroxyapatite(HA) coatings were deposited on titanium substrate by electrophoretic deposition in suspensions with dif-ferent HA powder contents.The surface and cross-sectional morphologies and phase composition of the as-prepared coatings were characterized by scanning electronic microscopy and X-ray diffraction.The bonding strength between the coating and substrate was tested by a shear strength testing experiment.The results show that suspension HA powder content has a significant effect on the mi-crostructure of the deposited coating,and further on its sintering property and the bonding strength between the coating and substrate.The increase in suspension HA powder content is beneficial in producing dense green coating,improving the sintering process of coating and the oxidation resistance of the substrate,and consequently increasing the bonding strength.The bonding strength between the HA coating and titanium substrate can be increased from 4.54 MPa with a suspension HA powder content of 5 g/L to 19.92 MPa with a suspension HA powder content of 20 g/L.国家自然科学基金(20573086);; 国家科技支撑计划(2007BAE051304);; 厦门市科技计划(3502Z20063005)资助项

Electrochemical Study on Electroless Nickel Plating Using Sodium Borohydride as the Reductant

We studied electroless Ni-B plating with sodium borohydride as the reductant by linear sweep voltammetry. The effects of bath solution composition and operating conditions on the cathodic reduction and anodic oxidation were studied. Increases in the concentrations of nickel acetate and sodium borohydride accelerated the reduction of Ni(2+) and the oxidation of BH(4)(-), respectively. Ethylenediamine, sodium hydroxide, thiourea and saccharin sodium inhibited both the cathodic and anodic reactions to varying degrees. Additionally, sulfur in the additives promoted the dissolution of nickel. High temperature was beneficial to both the cathodic reduction and anodic oxidation.National Natural Science Foundation of China[20573086

The Effect of Ion Exchangers on the Corrosion Behavior of Carbon Steel Under Organic Coatings

[中文文摘]为探讨在离子选择性涂层中离子交换体的不同对金属腐蚀行为的影响 ,用动电位扫描极化曲线和电化学交流阻抗技术研究了A3钢表面涂装含不同离子交换体的阴离子选择性和阳离子选择性有机涂层在 3%NaCl溶液中的腐蚀和电化学行为。实验结果表明 ,同一种涂层中不同离子交换体对碳钢的腐蚀行为有不同影响 ,可以通过选择具有缓蚀作用的交换离子来改善涂层的防蚀性能。在阴离子选择性涂层中交换离子为MoO2 - 4型时对碳钢的防蚀性能比交换离子为SO2 - 4型好 ,在阳离子选择性涂层中则交换离子为Na+ 型时比交换离子为NH+ 4 型好。[英文文摘]In order to study the effect of different ion exchangers on the corrosion behavior of metal under ion-selective organic coatings potentio-dynamic and electrochemical impedance spectroscopy (EIS) techniques were employed to investigate the corrosion and electrochemical behavier of A3 steel covered with anion-selective and cation selective-organic coatings in 3% NaC1 solution. The results shows that the different ion exchangers in the same ion-selective organic coating have different effect on the corrosion behavior of carbon steel. MoO2 - 4 - type anion exchanger has better anti - corrosion performance than SO2 -4 - type anion exchanger in anion - selective organic coating , whereas N4 + 4 + type cation exchanger has better anti - corrosion performance than NH+ 4 - type cation exchanger in cation - selective organic coating. Hence the anti - corrosion perfor2 mance of ion - selective organic coating can be improved by choosing the ion exchanger possessing inhibitory effect

沉积温度对纳米ZrN涂层结构及性能的影响

利用磁控溅射方法通过改变沉积温度(Ts)制备一系列纳米ZrN涂层.采用X射线衍射、扫描电镜及CSM纳米力学综合测试系统表征了纳米ZrN涂层的物相结构、截面形貌及综合力学性能,系统研究了沉积温度对纳米ZrN涂层结构及性能的影响.实验结果表明:随着沉积温度的增加,涂层择优取向由(111)变为(200),而在600℃时结晶度很低;涂层择优取向的变化是由涂层沉积过程中原子迁移能力和不同取向表面能的差异所决定的.纳米ZrN涂层在Ts=450℃及以下温度区间为柱状结构,并随沉积温度增加柱状晶逐渐变宽,在Ts=600℃时,由于生长方式的改变使涂层变为非柱状等轴结构.纳米ZrN涂层的硬度在Ts=450℃及以下温度区间没有明显变化,但在Ts=600℃时,由于涂层结晶度以及位错密度降低导致涂层硬度下降.随沉积温度的增加,涂层与基体间结合力先减小后增大.纳米ZrN涂层的磨损率由硬度和膜基结合力共同作用决定

Preparation of Co-YSZ/HAp Nano-composite Coating on Ti Substrate by Electrochemical Method

采用复合电沉积和电泳沉积两步法在钛基体上制备了Co-YSZ/HAp纳米复合涂层,与只采用电泳沉积法在钛基体上制备纳米HAp单一涂层进行了比较研究.采用场发射扫描电镜、X射线衍射和能量散射谱对复合涂层的微观形貌,纳米HAp外层表面形貌,晶相,复合涂层的断面形貌及元素组成分布进行分析研究.通过粘结-拉伸实验测定了涂层与基体的结合强度,结果表明,Co-YSZ/HAp纳米复合涂层与钛基体的结合强度明显高于纳米HAp单一涂层与钛基体的结合强度,说明复合涂层具有更好的力学性能.Co-YSZ/HAp nano-composite coating and nano-HAp single coating were deposited on Ti substrate using the combination of electrocodeposition and electrophoretic deposition, and electrophoretic depositions, respectively. Surface and cross section morphologies of the coatings were observed by scanning electron microscope. Element distribution and crystal phase of the coatings were analyzed by energy dispersive spectrum and X-ray diffraction. The adhesive strength of the coating and Ti substrate was determined by shear strength testing. The results indicate that the adhesive strength of Co-YSZ/HAp nano-composite coating and Ti substrate is higher than that of nano-HAp single coating and Ti substrate. It shows that Co-YSZ as an interlayer reduces the mismatch of the thermal expansion coefficients between HAp and titanium and Co-YSZ/HAp nano-composite coating has better mechanical properties.国家自然科学基金(20573086,200273055);; 福建省自然科学基金(E0210004)资助项