酸性锌镍合金电镀工艺参数对镀层镍含量的影响

研究了采用弱酸性氯化物体系电镀锌镍合金时镀液的镍锌比、温度、氯化铵含量,以及阴极电流密度、电镀方式等工艺参数对镀层镍含量的影响.结果表明,镀液镍锌比、温度、阴极电流密度对镀层镍含量影响较明显,氯化铵含量及磁力搅拌对镀层镍含量几乎无影响,采用脉冲电镀可以显著提高镀层镍含量.     

电子工业用镍包铜粉的工艺及性能研究

采用不同粒度的片状铜粉,以次磷酸钠作为还原剂,通过化学镀镍制备出性价比较高的、具有较好电磁屏蔽性能的镍包铜粉。讨论了铜粉粒径及镍含量对镍包铜性能的影响,结果表明,粒径大的铜粉较易进行化学镀镍,而镍包铜粉电阻随铜粉粒径减小而增大;随镍含量的减少,镍包铜粉的颜色变浅,电阻减小。SEM照片显示,镍包铜粉形貌较好,片状化程度较好。镍含量为30%时镍包铜粉磷含量较低,实际成分含量与理论相符,松装密度及导电性较好,是理想的电磁屏蔽材料。     

基于尿素中镍含量的测定探析

通常尿素中镍的含量大约在2×10^-6,用分光光度法测定镍的含量,准确率高,而且分析过程比较简单,测定速度也比较快,检测出的镍含量精密度好,这种检测方法完全可以满足工业生产需求。本文针对尿素中镍含量的测定展开探讨,分析镍元素测定过程中形成误差的原因及镍元素测定的注意事项。     

黑镍镀液中镍(Ⅱ)、锌(Ⅱ)及硫氰酸钾的快速分析

介绍了一种黑镍镀液中氯化镍、氯化锌和硫氰酸钾含量的快速分析方法:用分光光度法测定氯化镍和硫氰酸钾的含量;用标准EDTA溶液滴定法测定镍锌总量;氯化锌的含量则由镍锌总量扣除镍的含量后获得.该方法的回收率高(NiCl295.0%,KSCN 96.8%,ZnCl292.9%),操作简便,快速、准确.     

关于工业碳酸镍国家行业标准的讨论

在采用国家标准GB/T 26521-2011《工业碳酸镍》对市售的工业碱式碳酸镍测试时发现：镍的含量一直无法达标。通过与行业标准HG/T 2824-2009《工业硫酸镍》对比研究发现：两者只是待测试样不同,测试所需试剂、用量及实验条件等完全相同。但是碳酸镍中的镍含量与硫酸镍中镍含量不同。通过对盐酸和丁二酮肟用量的理论推导和实验验证,对GB/T 26521-2011提出了修订完善的方法和建议。     

溶胶-凝胶法制备油脂加氢催化剂的研究

采用溶胶－凝胶法，制备了可用于食用油脂加氢的单元镍催化剂，研究了催化剂制备方法对催化剂镍含量的影响及镍含量的变化对活性的影响。研究表明：镍含量最佳值在20％左右，催化剂的活性随镍含量增加而提高，采用乙醇代替水洗可有效提高催化剂的镍含量和催化活性。     

低速电沉积钯镍合金工艺的研究

通过极化曲线研究了钯、镍的电沉积行为.讨论了钯镍浓度比、pH值、电流密度、沉积电势等工艺参数对低速电沉积钯镍合金组成的影响.结果表明:与钯相比,镍的极化大,极化度也大;电沉积合金时,钯催化镍的沉积,而镍阻化钯的沉积.合金组成是各工艺参数的函数,镀液中钯、镍离子浓度比是影响合金成分的主要因素.随着镀液中Ni/Pd值的增大,合金中镍含量呈线性增加;pH值升高,合金中镍含量降低;电流密度增大或者沉积电势负移,合金中镍含量增加;沉积电势对合金成分的影响更显著,成分更易控制.     

丁二酮肟重量法测定镍钴铝氢氧化物中镍含量

试样经盐酸溶解,以酒石酸氨性溶液掩蔽杂质离子,以丁二酮肟乙醇溶液沉淀镍,沉淀干燥至恒重,建立了镍钴铝氢氧化物中镍含量的测定方法.结果表明:加入10 mL酒石酸溶液掩蔽干扰离子后,大量的钴、铝基体不会对测定造成干扰,滤液中镍含量约为0.04％ ～0.10％之间,无需补正滤液中镍含量,方法分析速度快、结果准确可靠,RSD不...     

碱性锌-镍合金镀液及镀层中锌、镍的测定

酸性锌-镍合金镀液中锌、镍的测定方法报道很多，而碱性镀液中锌、镍的测定报道很少。采用过硫酸铵作氧化剂，在碱性介质中，镍与丁二酮肟生成红色络合物借此比色，求出镍含量；用EDTA滴定法确定锌、镍总量，然后减去镍量从中得到锌含量。此方法也可用于镀层中的锌及镍测定。本方法测定结果准确、快速，能满足实际生产的要求。     

新型耐碱腐蚀合金铸铁的研制

本试验设计了一系列变化镍含量的Ni-Cr耐碱腐蚀合金铸铁和变化铜含量的Ni-CrCu耐碱腐蚀合金铸铁。采用光学显微镜观察合金铸铁的显微组织,用失重法测定合金铸铁在动态、高温、高浓度烧碱腐蚀溶液中的腐蚀速率,借助扫描电镜观察材料的腐蚀产物形貌并通过能谱仪进行微区元素含量分析。研究镍、铜合金元素对铸铁中石墨形态、显微组织的影响规律及其对耐碱腐蚀性能的作用规律,对比各合金铸铁的腐蚀速率,寻找镍铜当量,研制出新型铜代镍型合金铸铁,从而降低合金铸铁的成本。试验结果表明：在镍达到一定含量的基础上Ni-Cr合金铸铁中加入适量的铜,合金铸铁的耐碱腐蚀性能提高,且铜的镍当量为0.429。     

碱性锌镍合金电镀白钝化工艺的研究

研究了不同镍含量的锌镍合金镀层低铬白钝化工艺，通过中性盐雾试验。比较了不同钝化工艺对不同镍含量的锌镍合金镀层耐蚀性的影响，结果表明，不同镍含量的锌镍合金镀层需采用不同的白钝化工艺。     

Gold wire bondability of electroless gold plating using disulfiteaurate complex

Generally, contact or terminal areas are coated with nickel as a barrier layer; subsequently, gold plating is performed to maintain reliability of electrical interconnection. Treatment using dilute solutions of palladium ions have been applied to initiate electroless nickel plating on copper substrates because copper has no catalytic action for the oxidation of hypophosphite. However, trace amounts of palladium ions may remain on the unwanted areas and extraneous nickel deposits are often observed. We confirmed that nickel films without extraneous deposits can be formed using the activation solutions containing dimethyl amine borane (DMAB). Bondability on the electrolessly deposited gold was greatly influenced by the phosphorus contents of the deposited nickel films as the underlayer. Bonding strength after electroless gold plating was increased with increasing phosphorus contents in the nickel films. Stabilizers in the electroless gold plating also influenced the bonding strength. Baths containing cupferron or potassium nickel cyanide as a stabilizer showed superior bondability. Gold deposits having strong orientation with Au(220) and Au(311) indicated high bond strength.     

加氢处理温度对渣油中杂质脱除率的影响

利用渣油加氢中试装置,考察了原料渣油在不同反应温度下经级配催化剂加氢处理前后渣油性质的变化,揭示了硫、氮、镍、钒和残炭的脱除分布规律。结果表明,在恒定温度下,随催化剂活性增加,加氢处理渣油中硫、氮、镍、钒和残炭的含量降低;随反应温度升高,同一反应器得到的渣油杂质含量降低。硫、氮、镍、钒和残炭的总脱除率随反应温度增加而增加,但杂质在各反应器中的脱除率分布不同,50％的镍和60％的钒在前两个反应器中脱除,硫主要在R3和R4反应器中脱除,氮主要在R4和凡反应器中脱除,而残炭则在R5、R4和R5反应器中脱除,随温度变化杂质的脱除率分布呈现各自的变化趋势。     

镍基导电涂料微波反射性能研究

以微米镍粉和丙烯酸乳液为原料制备复合导电涂料,研究了涂料中镍粉和水的含量以及涂层厚度对涂膜微波反射率的影响,并分析了涂膜的微观结构.结果表明,当镍粉含量为40%～50%、水为20%～30%时,所得涂膜中镍粉分散均匀;当涂层厚度为(140±8)μm时,涂膜在频率为2～18 GHz范围内的微波反射率最高,达到铝板的60%～...     

Preparation and EMI shielding properties of nickel‐coated PET fiber filled epoxy composites

Electrically conductive composites were prepared using epoxy resin (EP) as matrix and nickel‐coated polyethylene teraphthalate (PET) fibers as filler. The fibers were coated with nickel by plating and ultrasonic electroless deposition techniques. The coaxial transmission line method was used to measure the electromagnetic interference (EMI) shielding effectiveness of the nickel‐coated PET fiber/EP composites. The contents of nickel and phosphorus in the coating were determined by X‐ray photoelectron spectroscopy (XPS). As a result, the ultrasonic electroless nickel‐coated PET fiber/EP composites showed excellent electrical conductive capability and better EMI shielding effectiveness due to higher content of nickel and lower content of phosphorus in the coating than conventional plated nickel‐coated PET fiber/EP composites. POLYM. COMPOS., 27:24–29, 2006. © 2005 Society of Plastics Engineers     

Wood liquefaction: Extended batch reactions using raney nickel catalyst

Extended batch reactions, in which poplar is treated at 340°C in the presence of Raney nickel, water and hydrogen, give oil in yields of 36-41% with oxygen contents of 12-17%. Methane and carbon dioxide formation, hydrogen utilisation and cracking of the oil are favoured by fresh Raney nickel. There is some competition for methane and carbon dioxide production, higher hydrogen pressures favouring the former in the presence of fresh catalyst. Efficient mass transfer increases hydrogen utilisation and lowers the oil viscosity. It is concluded that Raney nickel has no significant advantage over other more convenient forms of nickel.     

Ni-MCM-41的水热合成与稳定性

以硅酸钠(Na2SiO39H2O)、氯化镍(NiCl2·6H2O)等无机盐为原料,通过水热法合成含有不同镍含量的介孔分子筛(nickel-containing meso-porousmoleeular sieve,Ni-MCM-41).采用X射线粉末衍射、等离子发射光谱、程序升温还原,透射电子显微镜和N2吸附-脱附等技术对焙烧后的样品的物化性能进行表征,同时对所合成Ni-MCM-41的水热稳定性进行研究.结果表明:在水热条件下成功合成出4种不同镍含量的Ni-MCM-41,其比表面积在495.9～888.2 m2/g之间,平均孔径在2.43～2.92 nm之间.随着介孔分子筛中金属镍含量的增加,Ni-MCM-41的比表面积、孔体积变小和介孔有序性变差.原料摩尔比n(SiO2):n(NiO)1:0.05时,合成的Ni-MCM-41的介孔有序性最好.所合成的含Ni-MCM-41经750℃焙烧3h后仍然具有介孔结构;另一方面,经100℃水热处理5d后的样品也具有介孔结构,但介孔有序性差.     

镍催化剂的TPR研究

本文采用热导一程序升温还原法研究镍催化剂的还原性能.观察到在该体系催化剂上存在三种不同形态的氧化镍,其还原温度和还原活化能有着显著的差别.它们的相对含量与催化剂的制备方法、焙烧条件和再氧化温度等有密切的关系.适当改变这些条件,三种不同形态的氧化镍可互相转化.     

煤制合成气中羰基镍和羰基铁的测定

煤制天然气过程中产生的羰基镍、羰基铁可对甲烷化催化剂造成不可逆的中毒反应。氯化碘甲醇溶液(碘、氢碘酸、盐酸和甲醇的混合溶液)可同时吸收合成气中的羰基镍和羰基铁,再利用石墨炉原子吸收光谱仪测定羰基镍和羰基铁含量。通过该方法测定出合成气中羰基镍的含量约为0.025 mg/L,羰基铁的含量小于0.001 mg/L。吸收液中碘浓度为6.0 g/L,氢碘酸浓度为100 mL/L最宜。羰基化合物总含量较低,不会使甲烷化催化剂中毒;在取样和测定过程中应注意个人防护,防止甲醇或CO中毒。     

Trace metal contents,chemical properties and oxidative stability of capelin and herring oils produced in norwegian plants

The iron and copper contents of 14 crude capelin oils, two herring oils and one blend produced in oil meal plants in northern Norway were determined by atomic absorption spectroscopy (AAS). Their oxidative stability, peroxide (PV), benzidine (BV) and iodine values (IV), free fatty acids (FFA) and tocopherol contents were also evaluated. The oxidative stability was found to be more dependent on the tocopherol content and BV of the crude oils than on their content of trace metals. Changes in iron, copper and nickel contents were determined by AAS after refining and hydrogenation of marine oils in two Norwegian hydrogenation plants. The content of trace metals in the oils and hydrogenated products decreased as a result of alkali refining and bleaching to the lower limits of detectability by the method used, and amounted to 0.01 (oils), 0.02 and <0.3 ppm for iron, copper and nickel respectively.