Composite Plating of Ni/SiC Using a Cationic Surfactant with an Azobenzene Group
Composite Plating of Ni/SiC Using a Cationic Surfactant with an Azobenzene Group
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使用具有偶氮苯基团的阳离子表面活性剂复合镀Ni/SiC
DOI：
10.1149/1.1342176
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
T. Saji
中科院分区：
文献类型：
--
作者：
N. K. Shrestha;I. Miwa;T. Saji
通过从含有悬浮颗粒的瓦茨镀液中电沉积镍，在阳离子表面活性剂~AZTAB！的帮助下，高体积分数的碳化硅均匀地共沉积到镍基中。含有偶氮苯基的。研究表明，与已报道的其他表面活性剂相比，AZTAB能促进碳化硅的共沉积。结果表明，粒子共沉积的这种增强与沉积过程中阴极表面AZTAB的还原有关。研究了颗粒负载量、电流密度和温度对共沉积程度的影响。在最佳工艺条件下，共沉积的碳化硅在镍基中的最大体积分数为62.4%。由于具有较高的硬度和耐磨性，含碳化硅弥散相的金属基复合材料的工业性能越来越重要。然而，这些性能的大小取决于碳化硅的体积百分比。为了增加碳化硅颗粒在这种复合材料中的掺入量，许多研究人员探索了在电解槽中使用各种添加剂和表面活性剂的方法。1-4 Ehrsam 5声称，油基二甲胺氧化物表面活性剂可使约48vol%的碳化硅分散到镍基质中。然而，这需要更大的金额~600gdm 23！镀液中的碳化硅。Helle 6提出，氟碳表面活性剂可以促进高达50%的碳化硅共沉积。最近，我们证明了含有偶氮苯基团的非离子表面活性剂在还原时失去了两亲性，并将这一现象应用于贱金属表面有机颜料膜的化学镀。本文报道了一种含有偶氮苯基~AZTAB的阳离子表面活性剂在镍/碳化硅上的复合电镀，使复合材料中的碳化硅颗粒含量增加。AZTAB--阳离子表面活性剂~AZTAB！由对乙基苯胺与苯酚偶氮化，然后用1，2-二溴乙烷乙基化，再用三甲胺季铵化合成。8将AZTAB黄色粉末溶于水中过滤。在滤液中加入过量的丙酮，然后用力摇动混合物。然后，通过真空蒸馏将液体蒸发。生成的物质在空气中干燥，并在乙醇中溶解。最后在乙醚中重结晶。所有的电镀实验都是在一个直径约4厘米的烧杯中进行的，容量约为75毫升！镀液的组成和操作条件如表I所示。当镀镍液为50mL时，首先溶解AZTAB并加入碳化硅颗粒。在使用之前，将该浴液超声5分钟，然后搅拌30分钟，以确保表面活性剂在颗粒上的均匀吸附。标示为1毫米大小的a型碳化硅颗粒~清川化学，日本！在未经净化的情况下使用。没有检查镀液中颗粒大小的实际分布。然而，通过在导电胶带上喷洒碳化硅粉末来研究微量的碳化硅粉末，并在这些颗粒上覆盖一层金的薄膜。然后用扫描电子显微镜~SEM！对其进行检查。这样观察到的颗粒约为1-5毫米~图7A！以铜板为衬底，镍板为阳极。这些电极是用金属抛光剂Pikal~Nihon Maryo-Kogyo株式会社抛光的！然后用丙酮和氯仿超声5min。阴极的活性几何尺寸为0.0 3 3 1 3 1.5 cm，阳极的活性几何尺寸为0.0 5 3 2 32 cm。这些电极垂直放置，彼此平行，相距2厘米。在电解过程中，为了提高碳化硅颗粒在镀液中的分散性，用磁力搅拌器连续恒速搅拌镀液。沉淀物的分析。-电解后，沉淀物随后用蒸馏水和丙酮冲洗。在丙酮中对每个样品进行10min的超声波清洗，以去除表面疏松吸附的碳化硅颗粒。最后用丙酮漂洗，并在空气中干燥。用扫描电子显微镜观察了涂层的表面和横截面的形貌，用能量色散X射线能谱分析了共沉积层和碳化硅的含量。显微分析仪与扫描电子显微镜联用，放大100倍，加速电压15千伏。原子序数Z、吸收系数A和荧光修正系数F！校正后的EDX数据被用来根据相应的KA线的强度来确定镍和硅的原子百分比。在每个涂层的三个不同位置检查了共沉积量，并计算了这些沉积元素的平均体积百分比。由此计算的硅的体积百分比在这里被表示为涂层中的碳化硅的总含量。通过分析在相同的最佳条件下制备的涂层的10个复制品，检验了涂层的重现性。
A high volume percentage of SiC was uniformly codeposited into a nickel matrix by electrodeposition of nickel from a Watts bath containing particles in suspension which were dispersed with the aid of a cationic surfactant ~AZTAB! containing an azobenzene group. Studies show that AZTAB compared to other surfactants so far reported enhances the codeposition of SiC. It is proposed that this enhancement in the codeposition of the particles is related to the reduction of AZTAB at the cathode surface during the deposition of nickel. The effects of particle loading, current density, and temperature on the extent of codeposition were also studied. At the optimum condition, the maximum volume percentage of the codeposited SiC in the nickel matrix was 62.4%. The industrial performance of metal matrix composites with a SiC-dispersed phase is growing in importance due to the high degree of hardness and wear resistance. However, the magnitude of these properties depends on the volume percentage of SiC. In an attempt to increase the incorporation of SiC particles in such composite the use of various additives and surfactants in an electrolytic bath has been explored by many researchers. 1-4 Ehrsam 5 claimed that the oleyl dimethyl amine oxide surfactant yields a disperseion of about 48 vol % SiC into a nickel matrix. However, this required a much larger amount ~ 600 gd m 23 ! of SiC in the plating bath. Helle 6 proposed that a fluorocarbon surfactant could promote the codeposition of SiC up to 50 vol %. Recently, we demonstrated that a nonionic surfactant containing an azobenzene group loses its amphiphilic function upon reduction, and this phenomenon was applied to the electroless plating of organic pigment films on base metals. 7 In this paper, we report composite plating of Ni/SiC using a cationic surfactant containing an azobenzene group ~AZTAB, Fig. 1!, which enabled us to increase the content of SiC particles in the composite. Experimental Synthesis of AZTAB.—The cationic surfactant ~AZTAB! was synthesized by azo-coupling of n-p-ethylaniline with phenol, followed by ethylation with 1,2-dibromoethane and quaternization with trimethylamine as previously described. 8 The yellow powder of AZTAB was dissolved in water and filtered. An excess volume of acetone was added to the filtrate, and the mixture was shaken vigorously. Then, liquid was evaporated by vacuum distillation. The resultant mass was dried in air and dissolved in ethanol. Finally, it was recrystalized in diethyl ether. Plating procedure.—All plating experiments were performed in a beaker ~4 cm diam, capacity of about 75 mL!. The composition and the operating conditions of the bath are shown in Table I. To 50 mL of the nickel bath, AZTAB was first dissolved and SiC particles added. This bath was sonicated for 5 min and then stirred for 30 min prior to use to ensure uniform adsorption of the surfactant on the particles. The a-type SiC particles labeled as 1 mm particle size ~Soekawa Chemicals, Japan! were used without purification. The actual distribution of the particle size in the plating bath was not examined. However, a trace amount of the SiC powder was studied by spraying the powder on a conducting adhesive tape and a thin film of gold was coated over these particles. It was then examined using a scanning electron microscope ~SEM!. The particles thus observed were about 1-5 mm ~Fig. 7a!. The substrate was a copper plate and a nickel plate was used as the anode. These electrodes were cleaned by polishing with the metal polishing reagent Pikal ~Nihon Maryo-Kogyo Co., Ltd.! followed by sonicating with acetone and chloroform for 5 min. The active geometry of the cathode was 0.03 3 1 3 1.5 cm and that of the anode was 0.05 3 2 3 2 cm on either sides. These electrodes were held vertically at a distance of 2 cm apart, parallel to each other. During the electrolysis, the bath was continuously stirred at a constant speed with a magnetic stirrer in order to enhance the dispersion of the SiC particles in the bath. Analysis of deposits.—After electrolysis, the deposits were rinsed subsequently in distilled water and acetone. Ultrasonic cleaning in acetone was applied for 10 min on each sample in order to remove loosely adsorbed SiC particles from the surface. Finally it was rinsed with acetone and dried in air. The morphology of the surface and cross section of the coatings were examined using a SEM and the amount of codeposits and SiC was determined using an energy dispersive X-ray ~EDX! microanalyzer coupled to the SEM at a magnification of 100 times and an accelerating voltage of 15 kV. The ZAF ~factors of atomic number Z, absorption A, and fluorescence correction F ! corrected EDX data were used to determine the atomic percentages of nickel and silicon from the intensity of the respective Ka lines. The amount of codeposits was examined at three different locations of each coating and the average volume percentage of these deposited elements was calculated. The volume percentage of Si thus calculated is represented here as the total content of SiC in the coatings. The reproducibility of the coating was examined by analyzing the ten replicas of the coating prepared under the same optimum condition.