稀土在金属表面处理工艺中的应用技术(3)——稀土对提高酸性亮铜镀层低区走位和抗变色能力的影响

介绍了稀土在光亮酸性镀铜中应用的工艺配方和工艺条件以及镀液中各成分对工艺规范的影响;分析了不同的故障现象和相对应的原因,以便及时调整处理,着重介绍了在酸性光亮镀铜工艺中使用稀土添加剂后的三个优点:(1)能提高光亮镀铜层的抗变色性,从而提高整体镀层的结合力和抗蚀能力;(2)能扩大光亮镀铜层的光亮范围和低区走位能力;(3)提高镀液对杂质和容忍能力的稳定性,延长镀液使用时间,减少大处理的次数和成本.     

印制线路板酸性镀铜组合添加剂的工艺性能

目前,酸性镀铜难以满足高端PCB生产需要,在酸性电镀溶液中加入组合添加剂FX-203制备电镀铜层,采用霍尔槽法、电化学、SEM和XRD等研究了该添加剂对镀层质量、镀液性能的影响。结果表明：随着FX-203加入量的增大,镀层光亮区和镀液分散能力先增大后减小。该体系适宜的工艺条件：75g／L CuSO4·5H2O,180g...     

钢铁酸性直接镀铜工艺

钢铁酸性直接镀铜工艺具有节能、环保双重优点.采用250 mL赫尔槽和加热急冷等方法,研究了组合添加荆GB-93在钢铁酸性直接镀铜中对镀层光亮范围、孔隙率、阴极电流效率、镀液深镀能力和镀层与基体结合力的影响.结果表明,通过加入GB-93添加剂,可在钢铁基体上直接电镀出光亮、结合力好的酸性铜层,可用于管件、盲孔件、铸铁件,也可用于滚镀或继续加厚其他镀层.酸性直接镀铜工艺解决了钢铁在碱性无氰镀铜中因钝化而导致结合力不良的问题,亦解决了钢铁管状件在电镀酸铜时内孔易出现铜粉的难题,可以代替剧毒的氰化铜预镀工艺.试验获得最佳工艺条件:20 g/L CuSO4·5H2O,40 g/L H2SO4,15mL/LGB-93A主剂 ,15 mL/L GB-93B助光剂,阴极电流电流密度0.8 A/dm2,温度30℃,电镀时间3 min.在上述工艺条件下,可以得到较高的阴极电流效率和良好的结合力.     

CT—1型氯化钾微酸性光亮镀锌

一、前言自六十年代无氰电镀问世以来,在微酸性镀锌中主要采用铵盐镀锌.但由于镀层钝化膜容易变色,镀液冬天易结晶,夏天锌离子浓度容易升高,废水处理困难等缺点,因而阻碍了铵盐镀锌的进一步发展.七十年代国外对无铵微酸性镀锌体系进行了广泛地研究,1978年正式应用于生产;国内近两年来也开始研究和应用. 我们采用自行合成的添加剂CT-1型氯化钾微酸性光亮镀锌工艺,经过两年多的系统试验和生产应用及有关单位的试用证明,本镀液具有电流效率高、沉积速度快、镀层光亮、抗变色能力强,对铸铁件易于施镀等优点.现予介绍供参考.     

稀土在金属表面处理工艺中的应用技术(4)——稀土添加剂对提高镀镍及镍铁合金镀层耐蚀性的影响

通过在镀液中加入稀土添加剂,获得了半光亮镀镍、光亮镀镍和镍铁合金镀层,采用显微观察贴滤纸法和5%的NaCl溶液浸泡试验考察了镀层的表面形貌、孔隙率和耐蚀性能.结果表明,加入稀土添加剂的镀镍层表面细致;镀层的孔隙率明显降低,镀镍层的耐蚀能力得到提高.     

氯化物镀锌层变色的原因及其解决方法

１变色表现氯化物光亮镀锌层变色主要有以下几种：（１）工件从槽液中取出后,外观光亮,若出光或钝化,镀层变黄色甚至变黑;（２）工件钝化后,亮度很好,但短时间内镀层即失光、发黄、变暗;（３）镀层光亮不持久,特别在恶劣的运输或使用环境中,工件镀层变色严重,甚至长出白霜。２变色原因（１）镀液由于氯化物镀锌工艺对光亮剂的依赖性较强以及光亮剂原料中含硫有机物在镀层中的夹杂,使得镀层变色不可避免。有研究表明,在氯化物镀锌基础液中加入０．２ｇ／Ｌ稀土氧化物,可明显提高镀锌层的抗变色性。（２）镀液中含有…     

酸性镀铜中Cu-2O的危害及控制

酸性镀铜具有成分简单、成本低、维护方便等优点。目前 ,酸性镀铜 (特别是光亮酸性镀铜 )技术已非常成熟 ,在工业生产中占有很重要的地位 ,但在实际生产中光亮酸性镀铜溶液经常会出现各种故障 ,影响了铜镀层的质量 ,特别是铜粉 (Ｃｕ2 Ｏ)对酸性镀铜溶液影响很大 ,有效地避免铜粉在镀铜溶液中的产生 ,将有利于提高镀铜质量。1　Ｃｕ2 Ｏ对酸性镀铜的危害镀液中Ｃｕ2 Ｏ沉淀 ,在电镀过程中Ｃｕ2 Ｏ会附着在工件上形成粗糙毛刺 ,使镀层光亮度下降 ,低电流密度区不亮、镀液整平性能降低、镀层粗糙度加大等。2　原因分析2 .1　铜阳极的含磷量采…     

江苏宜兴市邮堂化工原料厂——稀土系列电镀添加剂专业生产厂

1、998Ａ稀土耐蚀薄镍电镀添加剂———节镍镀镍佳品,国内首家独产(1)适用于使用各种国产、进口光亮剂的半光亮镀镍、滚镀镍和光亮镀镍。(2)原镀镍工艺不变,只加998Ａ0.3～0.8克/升,(补加量20～40克/千安·时),滚镀和吊镀时间缩短20%～50%,自动线或时间不能缩短的镀种,可将电流降低20%～50%,镍层减薄,经测金属镍和镍盐消耗减少。(3)减薄镍层,镀镍成本明显降低,但结晶细化,孔隙率降低,稀土镍基合金镀层的耐蚀能力经测反而略有提高,光亮度不变,而分散能力、整平性及韧性明显提高,本剂对镀镍液和光亮剂及后道镀层均无不良影响。本品粉剂,1000克…     

江苏宜兴市邮堂化工原料厂——稀土系列电镀添加剂专业生产厂

1、998Ａ稀土耐蚀薄镍电镀添加剂———节镍镀镍佳品 ,国内首家独产( 1)适用于使用各种国产、进口光亮剂的半光亮镀镍、滚镀镍和光亮镀镍。( 2 )原镀镍工艺不变 ,只加 998Ａ 0 .3～ 0 .8ｇ/Ｌ(补加量 2 0～ 4 0ｇ/ｋＡ·ｈ) ,滚镀和吊镀时间缩短 2 0 %～ 50 % ,自动线或时间不能缩短的镀种 ,可将电流降低 2 0 %～ 50 % ,镍层减薄 ,经测金属镍和镍盐消耗减少。( 3)减薄镍层 ,镀镍成本明显降低 ,但结晶细化 ,孔隙率降低 ,稀土镍基合金镀层的耐蚀能力经测反而略有提高 ,光亮度不变 ,而分散能力、整平性及韧性明显提高 ,本剂对镀镍液和光亮剂及…     

江苏宜兴市邮堂化工原料厂——稀土系列电镀添加剂专业生产厂

1、998Ａ稀土耐蚀薄镍电镀添加剂———节镍镀镍佳品 ,国内首家独产( 1)适用于使用各种国产、进口光亮剂的半光亮镀镍、滚镀镍和光亮镀镍。( 2 )原镀镍工艺不变 ,只加 998Ａ 0 .3～ 0 .8ｇ/Ｌ(补加量 2 0～ 40克 /千安·时 ) ,滚镀和吊镀时间缩短 2 0 %～ 50 % ,自动线或时间不能缩短的镀种 ,可将电流降低 2 0 %～ 50 % ,镍层减薄 ,经测金属镍和镍盐消耗减少。( 3 )减薄镍层 ,镀镍成本明显降低 ,但结晶细化 ,孔隙率降低 ,稀土镍基合金镀层的耐蚀能力经测反而略有提高 ,光亮度不变 ,而分散能力、整平性及韧性明显提高 ,本剂对镀镍液和光亮剂…     

Estimation of Parameters of Universal Distribution of Moments of Failure of Products

A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling.     

Assessment of intakes of mixtures of radionuclides

Australia has several uranium mines and a large number of mineral sand mines, with associated processing facilities. Exposures resulting from these mining and processing operations usually involve intakes of mixtures of radionuclides. This work describes the development of a suite of first order, linear compartment models, based on the ICRP Publication 66 respiratory tract model, and an analytical solution to the decay equations, for assessing the consequences of such intakes. The computer programs based on these models directly compute excretion, organ retention and organ and whole-body doses for intakes of either single radionuclides or any mixture of radionuclides belonging to the same radioactive decay chain. The intake can be via inhalation, ingestion or injection, and can be acute, chronic or of limited duration. The starting concentration and degree of secular (dis)equilibrium can be specified for each radionuclide. No assumptions need to be made about the relative magnitudes of the radioactive half-lives of the different nuclides.     

卧式金属罐容量的测量结果不确定度

本文根据多年的实践检定经验 ,参照JJF1 0 59- 1 999《测量不确定度评定与表示》以及《测量不确定度表达 1 0讲》 ,对卧式金属罐容量的测量结果不确定度进行了评定。     

盐酸浓度不确定度的评估

通过对盐酸浓度标定的过程分析，找出影响结果的各个分量，进行不确定度的评定，按照计量技术规范给出标准的表示法。     

Numerical study of methods of linearization of the output characteristics of radio-frequency sensors of the level of dielectric media

Different constructions of the sensing elements of radio-frequency level sensors based on sections of long lines are numerically investigated by means of the Matlab program for the purpose of minimizing the measurement error caused by the nonlinearity of the output characteristic. It is shown that the nonlinearity is lowest for U-shaped designs. The nonlinearity factor KN may be regulated by varying the capacitance of a correcting capacitor connected to the input of the sensing element and (or) the length of one of the sections of the long line. In selecting an optimal capacitance of the correcting capacitor KN ≤ 0.15% for control media with dielectric permittivity in the range 2.2–30.     

Possibilities of Decreasing the Errors of Determination of the Height of the Pole of a Sessile Drop of Melt

We analyze the possibilities of decreasing the errors of measuring the height of the pole of a sessile drop of melt above its equator by determining the position of the equator according to the midpoints of vertical chords of the image of the drop. The optimal distance between these chords and the edge of the image of the drop is chosen within 10–20% of the radius of the equator. The proposed method guarantees the same level of errors of evaluation of the height of the pole and the radius of the equator, which enables one to substantially increase the accuracy of evaluation of the capillary constant and the surface energy of the melt according to the geometric parameters of the sessile drop.     

Analysis of the rate of propagation of the wave of change of boiling modes

An approximate analytical expression is derived for the velocity of the front of the wave of change of boiling modes on a rod and on a plate. The impact of the Thomson effect and of the heater orientation in the gravity field is included. Adequate agreement is demonstrated between the derived relations and experimental data.