镀镍故障排除一例

镀镍故障排除一例重庆中国嘉陵工业股份有限公司九二二车间（６３００３２）王家中我们车间环形镀铬自动线是采用双层镍套铬工艺，即半光亮镍、光亮镍，套铬。过去一直生产较正常，后来光亮镍镀层突然出现大量气泡和爆皮。问题出现后，我们对光亮镍溶液采取一惯用的氧化吸...     

Nd-Fe-B粉末合金的多层电镀防护技术

用化学镀方法在Nd-Fe-B粉末合金多孔基体上施镀铜-镍合金或镍-磷合金底层，再电镀高硫镍和半光亮镍。研究了几类镀层对基体的封闭能力、耐蚀性，用恒电流阳极溶解法测定了多层体系的电位-时间曲线,并进行了镀层组织的金相检测。结果表明，化学镀Ni-P合金镀层对Nd-Fe-B基体有良好的封闭性能，高硫镍层的电位低于电镀半光亮Ni和Cu-Ni、Ni-P化学镀层，腐蚀可控制在高硫镍层中横向进行，Cu-Ni／Ni-P／高硫Ni／半光亮Ni体系和Ni-P／高硫Ni／半光亮Ni体系有极佳的防护性能。     

用中间体配制镀镍光亮剂初探

众所周知 ,含硫光亮镍较普通无硫光亮镍的活性大 (电位较负 )。但是 ,如果这种光亮镍镀层镀在半光亮 (用其他光亮剂得到的含硫 0 .0 0 3%或更少 )的镍底层上 ,则腐蚀往往被终止在两类镍镀层的交界面上。这是因为含硫的镀层比半光亮的底层电位负 ,于是被优先腐蚀 ,从而起到牺牲性防护作用。在钢铁基材上镀半光亮镍 高硫镍 光亮镍 ,这种三层电镀层的抗大气腐蚀的性能相当出色。镀镍用的商品光亮剂品种繁多 ,电镀厂家多根据自身要求选用。商品光亮剂也是供货厂家用中间体配制而成。笔者在工作实践中进行了镀镍光亮剂的自配试验 ,介绍如下。在…     

摩托车后减震器活塞杆电镀工艺

提出了一种适用于摩托车后减震器活塞杆的半光亮镍／高硫镍／光亮镍／硬铬电镀工艺，用该工艺电镀的活塞杆外表光亮，镀层结合力好，既耐磨又耐蚀，经３２ｈＣＡＳＳ试验，耐蚀性达９级以上。     

电镀装饰铬故障的分析及处理方法

分析了在镀半光亮镍／光亮镍／装饰铬的过程中，出现镀件下端铬层“发灰”的故障原因，并提出了解决方法。     

光亮硫酸镀铜液的维护

以硫酸、硫酸铜为基础液的光亮硫酸镀铜,具有成本低、三废处理方便、阴极电流效率高,光亮整平性好等优点,不少工厂用之取代了原有的焦磷酸盐镀铜工艺,我厂使用光亮硫酸镀铜液多年,下面简单谈谈它的日常维护要点。一、预镀光亮酸性硫酸镀铜液仅适于铅、铜、镍的直接镀铜,而不适于铁、铝,锌。在铁、铝、锌制品镀铜之前,要先在氰化镀铜液中进行预镀铜或在氰化镍溶液中预镀镍。而合金     

多层镍组合镀层试生产情况介绍

一、前言1984年3月以来,我厂对武汉材料保护研究所研制的多层镀镍工艺及其相关的添加剂进行了试验及试生产.共配制了以DN-1及冰醋酸为添加剂的半光亮镍溶液3800升;以TN-1为添加剂的高硫镍溶液400升;以BN-816及糖精为添加剂的光亮镍溶液1800升.在中试的基础上,自5月迄今,每天二班制正式用于生产.下面将我们半年多来从试验到用于生产的情况以及对该工艺的一些看法介绍如下. 二、工艺流程及工艺配方(一) 工艺流程: 化学除油→电化学除油→酸洗→低氰镀铜(也可不镀)→活化→镀半光亮镍→镀高硫镍→镀光亮镍→活化→镀铬.     

超弹性镍钛合金电镀前处理研究

研究了超弹性镍钛合金的电化学性质，镍钛合金表面存在的纯化膜而导致的镀层与基体结合力不良的问题，采用具有溶解和活化作用的浸蚀液以及合适的预镀层，并且选用具有整平能力的镀怪作用为中间镀层，从而得到结合力良好、外观平滑光亮的镀金层，解决了镍钛合金产品的装饰性问题。     

多层镍镀硬铬爆皮产生之因及消除法

多层镍镀硬铬是近年兴起的镀种，它具有多层镍层的高耐蚀性，又具有硬铬层的高硬度和高耐磨性，是性能优良的功能性镀层，常用于条件恶劣，硬度、耐磨性要求高的产品，如汽车、摩托车的减震器。这种镀层结构为总镍层厚度１５～２０μｍ，硬铬层１０～１５μｍ，半光亮镍层和光亮镍层之间的电位差在１２０ｍＶ以上，高硫镍层含硫量在０．１５％左右，硬铬层硬度达８００ＨＶ以上。和普通多层镍铬工艺相比，它的要求要高得多。普通多层镍铬电镀线上镀硬铬会出现大面积爆皮现象（既出现在基体同镀层之间，也出现在镍层和硬铬层之间）。试验认为…     

多层镍“过渡性镀层”对防护性能的影响

杭州自行车总厂自1984年3月引进武汉材料保护研究所的三层镍镀镍工艺以来,取得了较好的效果,尤其是对产品的抗腐蚀性能有突破性提高,是一种具有推广应用价值的先进电镀工艺。通过生产实践及测试,我们体会到要使多层镍具有优良的抗烛性能,必须具备三个条件: 1.镀层的总厚度应在20微米以上; 2.半光亮镍层与光亮镍层之间的电位差应大于125毫伏。高硫镍层的电位应比光亮镍层电位更负;     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.     

Study on Bond Ability of Arc-Spraying Coatings with Different Surface Pretreatment on Cast-Iron

Arc spraying coatings are widely used in various applications, but uncommon in cast iron substrate. Different surface pretreatment technology is tested on substrates of gray cast iron. Surface roughness and residual stress were measured by TR200 and X-ray diffraction analyzer. Influence of different surface pretreatment methods ( dry blasting and fusebond) on roughness and residual stress was analyzed. The arc-sprayed coatings of wire 3Cr13 (φ2mm) on gray cast iron substrate is studied. The microstructure and interface of bonding layer were observed by SEM. The bond strength was taken by tensile test. Results show that bond strength with grit blasting is higher than fuse-bond; it is feasible to make wire 3Cr13 coating with arc spraying on cast iron substrate roughened by grit blasting.     

Structural Characteristics of TiO2 Ceramic Coating by Micro-Plasma Oxidation

TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.     

Evaluation of fatigue life of steel using steel grain size

The insightful discussion of the relationship between the construction of metallographic and fatigue life and proposition of mathematical relationships describing this relationship was conducted in the paper. This paper presents a method for estimating the fatigue life, based on the construction of the microstructural material taking into account the grain size and the participation of ferrite and pearlite phase.