化学镀铜的应用与发展

化学镀铜现已广泛地应用于国防工业、机械制造、化学工业等领域。本文在叙述了化学镀铜技术及发展趋势的基础上,还对化学镀铜的常用方法和主要应用范围进行了说明。     

镁合金化学复合镀(Ni-P)-SiC纳米颗粒

研究了镁合金化学复合镀(Ni-P)-SiC纳米颗粒的制备工艺,并对复合镀层的性能进行测试,揭示了影响镀层性能的主要因素及变化规律。     

泡沫镍的制备工艺与性能

探讨了在聚氨酯泡沫塑料上用化学镀镍法制备泡沫镍的工艺和性能。经化学镀镍的可导电泡沫的电阻率越大 ,电铸时电流增加速度越慢 ;电阻率的偏差越大所得泡沫镍均匀性越差 ;泡沫镍的化学成分主要受原料镍纯度影响 ;构成泡沫镍网状结构的丝均为中空体 ,其截面呈三角形 ,中空微孔部分的体积占总孔隙率的 1 5 %～3 0 % ;各条件下所得产品孔隙率均大于 95 8%。     

Preparation of Ti–Ni binary powder via electroless nickel plating of titanium powder

Abstract

In this study, Ti powder (average size: 45 μm) was plated/coated by electroless Ni with hydrazine hydrate as reductant. The Ni plating was carried out at 85°C and pH 9–10. The influence of process parameters such as plating period as well as reductant concentration was investigated. The Ni plated Ti powder was characterised by scanning electron microscopy, energy dispersive spectrometer analysis and X-ray fluorescence. It is found that a pure/uniform Ni layer may be deposited on the Ti powder particles. The deposited mass increases as plating period/reductant concentration increases.     

The effects of ultrasonic vibration on mechanical properties of tungsten particle-reinforced copper-matrix composites

W-Cu micro-powder mixtures usually have poor sinterability due to the relatively low solubility of W in both solid and liquid Cu. In fabricating W-Cu composites, an electroless copper plating process is often used to coat Cu on the W particle surface prior to the sintering process. Due to their small size W particles tend to agglomerate during the plating process, hence the individual particle may not be properly coated with Cu. In this study, ultrasonic vibration is applied in the electroless plating process to break up the agglomerations and restrain the powders from gathering, ensuring a uniform deposition of the Cu on individual W particle. W-Cu composite samples containing pure Cu and 6, 9 and 12 wt-% of Cu-coated W particles, respectively, are fabricated using a standard powder metallurgy technique. It is shown that the application of ultrasonic vibration in the activation and deposition steps of the electroless copper plating process prevents W powder agglomeration and ensures that each W particle is coated with Cu. As a result, the mechanical properties of the W-Cu composites are significantly improved. It is found that the optimal tensile strength and yield strength are obtained using a W reinforcement phase content of 9 wt-%.     

化学镀Co-Ni-P合金镀层增厚过程中结构和形貌的改变

用电子探针，透射电镜，旋转阳极Ｘ射线衍射仪和原子力显微镜分析了观察了化学镀Ｃｏ－Ｎｉ－Ｐ合金镀层的成分，结构和表面形貌。化学镀Ｃｏ－Ｎｉ－Ｐ合金开始晶态沉积，表面由“圆锥峰”组成。镀层厚度是按叠层生长方式增加的。     

高强铝合金的化学镀镍镀层性能研究

对高强铝合金进行了化学镀镍,观察了镀层形貌,对镀后试样进行了不同温度的热处理以及耐热性能试验,研究结果表明:经该工艺处理后镀层胞状形貌明显,结构致密均匀,孔隙少,镀层光亮,结合力好。400℃以下化学镀层的硬度随热处理温度的升高而增大,400℃处理后,镀层与基体的界面元素扩散现象明显。镀层在一定温度下具有保护铝基体的作用,尤其在瞬时高温的条件下镀层的保护作用更加明显。     

Effect of La2Sn2O7 content on Ag-La2Sn2O7/SnO2 arc erosion behavior and mechanism

La₂ Sn₂ O₇/SnO₂ powder was synthesized by chemical co-precipitation method,and Ag-La₂ Sn₂ O₇/SnO₂ composites were prepared by hot-pressing sintering.The electrical resistivity,density,Brinell hardness and flexural strength of Ag-La₂ Sn₂ O₇/SnO₂ composites were measured.Moreover,the effect of La₂ Sn₂ O₇ content on the arc erosion beha...     

镍钴离子浓度比对化学镀Co-Ni-P合金组织结构和性能的影响

化学镀ＣｏＮｉＰ合金层镀态下为非晶态结构，以层片状沉积，表面有胞状结构。［Ｎｉ２＋］／［Ｃｏ２＋］的比值越大，胞块越大，晶化倾向越大，镀层显微硬度越高，矫顽力越小，矩形比越大。其易磁化方向与膜面垂直。随加热温度升高，化学镀ＣｏＮｉＰ合金发生了晶化转变，析出了第二相，显微硬度在４００℃／１ｈ热处理后达到最高值。     

酸性镀铜中铜粉产生的原因及控制

着重讨论了光亮酸性镀铜过程中“铜粉”产生的原因及其控制，从而有效避免铜粉在镀液中产生，保证了遮模产品的质量．     

化学复合镀及其应用

综述了近年来化学复合镀技术的进展，主要包括耐蚀性化学复合镀和自润滑化学复合镀的制备、特性及应用。化学复合镀层的性能受涂镀条件的影响，复合颗粒不影响镀层的微结构。     

铜精炼炉渣磨矿流程优化

采用闭路磨矿—压滤干排的方式处理铜精炼炉渣,会导致球磨机的台时能力降低。通过引入高频振动脱水筛,与旋流器和压滤机一起构成新的干排系统,使粗粒、细粒级进行了单独脱水,解决了球磨机排矿的脱水问题,实现了铜精炼炉渣的开路磨矿,既提高了球磨机的处理量,又降低了矿粉水分。     

化学镀法制备镍包石墨复合粉末

采用化学镀法在石墨粉末表面镀镍制备Ni/石墨复合粉末,采用激光衍射粒度分析、扫描电镜等对Ni/石墨复合粉末的粒度和表面形貌进行表征,研究镀液中主盐硫酸镍、还原剂联氨及活化剂氯化钯的浓度对该复合粉末表面形貌的影响,并对Ni镀层在石墨表面的生长机理进行探讨.结果表明:硫酸镍质量浓度为20 g/L、联氨体积分数为2％时,化学...     

银铜粉的研制及性能的研究

采用化学沉积法在微米级铜粉上镀银,并对得到的镀银铜粉的性能进行测试,对得到的结果进行了分析．     

不同粒度钨粉化学镀铜的研究

通过化学镀可以在钨粉颗粒表面均匀包覆铜层,从而改善钨铜合金的组织和性能.本文首先确定了钨粉化学镀铜的镀液温度,在此基础上研究了钨粉粒度对钨粉表面化学镀铜工艺的影响.分别采用XRD和SEM来分析W-Cu复合粉体的相组成和钨粉镀覆前后形貌及均匀性,以施镀同样重量的铜粉所需时间来描述镀速的相对快慢.结果表明:钨粉化学镀铜的适合镀液温度为45℃,此时镀速快,镀液稳定不分解,铜镀层致密;随着钨粉粒度变粗,镀速变慢,施镀时间延长,并且过粗的钨粉在镀液中不易悬浮,镀铜不充分;不同粒度的钨粉化学镀后都包覆一层成分单一的致密铜层,化学镀包覆的铜层是晶态的.     

Particle Densimetric Froude Number for Estimating Sediment Transport

It has been established that for ratios of flow depth to bed particle diameter less than ten (flow on very rough boundaries) neither the Reynolds number of the solid loose particles at a stream bed nor the Shields parameter are adequate variables to predict critical flow conditions for the initiation of motion. A particle densimetric Froude number F? = U/[(s?1)gD]1/2 (where U=mean velocity, s=ratio of sediment and fluid densities, g=acceleration due to gravity, and D=characteristic diameter of bed particle) is here proposed as an alternative criterion to predict hydraulic conditions for the initiation of motion. Values of critical F? were computed after calibration with available experimental data sets. After the critical conditions for the initiation of particle motion were exceeded, transport of bed particles was established. In order to evaluate the performance of a transport equation that contains F? in sediment transport, a set of the most employed formulations to estimate bed material transport in steep slope macrorough flows were tested. The comparison of the results shows that F? can be used to accurately predict sediment discharge.     

小电流镀铜对阳极氧化AZ31镁合金耐蚀性的影响

研究了小电流镀铜封孔对阳极氧化AZ31镁合金耐蚀性能的影响.AZ31镁合金阳极氧化后,在传统的镀铜液中进行阴极小电流处理.SEM、EDS和XRD分析结果表明,阴极小电流处理后,在阳极氧化膜的多孔层中发生了铜的沉积.在质量分数为3.5%NaCl水溶液中测试的极化曲线表明,AZ31镁合金阳极氧化后进行小电流镀铜处理,可以提高自腐蚀电位,降低自腐蚀电流密度,使耐蚀性能得到显著提高.     

不同表面处理条件下身管烧蚀研究

通过模拟发射试验对表面镀铬、氮碳共渗两种表面处理条件下的身管进行了烧蚀模拟测试,研究在模拟工况下身管烧蚀情况.镀铬身管由于镀铬层固有的脆性,且受到高温高压火药气体的冲击作用,铬层内易产生显微裂纹,裂纹扩展至铬层与基体界面处,并沿着镀层与基体界面扩展,从而导致镀层剥落.氮碳共渗身管在烧蚀过程中,表面产生大量较深且较宽的裂纹,裂纹直接贯穿到基体使基体严重地被火药燃烧气体腐蚀,从而导致身管失效.在上述研究基础上,提出了两种不同处理方式下身管的失效模式.     

Estimating the Oil Droplet Size Distributions in Deepwater Oil Spills

Oil released in a deepwater blowout breaks up into droplets. Hence, the time it takes for oil to reach the water surface, its location, and the size of the surface slick at a given time, are all affected by oil droplet sizes. Information on oil surfacing time, its location, and slick size are essential for emergency spill response as well as contingency planning. Despite the importance of the oil droplet size on oil fate in many oil spill problems, our ability to estimate oil droplet sizes has been poor. In this paper, methods are developed for a deepwater oil spill model to estimate the oil droplet size distribution generated due to an accidental release. Models for estimating oil droplet size distribution generated by a deepwater release are developed based on the maximum entropy formalism. The quality of results depends on the constraint equations used. The paper shows results using only the mass balance and specific surface area as constraint equations. The latter case showed markedly improved results. Model results for droplet size distribution are compared with limited experimental data.     

高强焊接用盘条镀铜脱落原因分析

高强焊接用盘条适合于生产650MPaCO2气体保护镀铜焊丝,其焊接工艺性能良好,要求盘条具有良好的综合力学性能,以便于拉拔加工。高强焊接用盘条在镀铜过程中有严重的镀铜不均匀、镀铜后镀层脱落及焊接过程中飞溅等现象,实验室模拟分析认为线材的组织缺陷是晶界氧化,控制退火温度不超过690℃,可以减少晶界氧化,防止镀铜脱落。