对铁管件镀铜-镍-铬工艺的一点改进

管状零件电镀铜 -镍 -铬镀层 ,由于管内无法预镀上一层氰化镀铜层 ,在镀酸性光亮铜时 ,造成管内产生置换镀层 ,这层置换层疏松 ,与铁的结合力极差 ,极易随着管内镀液的流出而将置换铜层碎片带入镀槽 ,而严重影响以后的正常电镀 ,造成零件的严重毛刺。为解决这一问题 ,我们进行了大量的试验 ,用以下两种方法基本解决了这一问题。一年多来先后电镀出口日本 1 0 mm× 1 0 0 0 mm细铁管镀铜的避雷地桩数万支 ,出口德国镀铜 -镍 -铬铁管床架数万只 ,效果良好。1　直接浸渍法该法是在镀酸性光亮铜前 ,先浸入浸铜液 ,然后再镀光亮铜以及其它镀层…     

锌合金压铸件仿古铜电镀

经过电镀铜再镀黑镍或电镀铜层着色的方式可以使锌合金压铸件获得典雅的古铜色，但镀铜前必须预镀镍或氰化预镀铜，镀后还需调色处理、涂漆处理。     

专利集锦

自行车零件铜镍铬电镀层的退镀方法 该发明属于自行车零件的铜镍铬电镀层加工技术,尤其是一种自行车零件的铜镍铬电镀层的退镀方法。发明解决了在保证退镀质量的前提下,减少电镀废弃溶液的排放量,达到节约资源和环保生产的目的。其特点是利用电镀生产中产生的废弃电镀溶液作为退镀溶液的一种组成部分,在一定的工艺条件下,使自行车零件的铜镍铬电镀层的退镀取得表面光滑干净的退镀质量效果。该发明主要应用在用碳钢材料制造的自行车车把、钢圈、辐条和轮轴等零件需要进行铜一镍一铬金属电镀加工的生产过程中使其具有防锈、耐磨和外表美观的性能。     

毛遂自荐

求职内容：本人从事电镀工作20余年,一直在一线从事电镀工艺的开发与研制,熟练掌握不同金属底材（如铜、钢铁、锌合金、不锈钢、铝合金）等电镀与化学镀工艺,熟悉碱铜、酸铜、半光镍、冲击镍、多层镍、光镍、装饰铬、氰化物镀锌、氯化物镀锌等挂镀、滚镀工艺,能独立配制和维护镀液,能及时有效处理生产过程中出现的相关问题,     

电镀故障中的假象及其识别

关于故障中的假象问题 从下述3个实例,可了解电镀故障中的假象。实例1自行车瓦盖又称挡泥板,电镀铜、镍、铬。工艺流程：镀前处理——预镀镍——光亮硫酸盐镀铜——全光亮镀镍。在电镀过程中发现镀件从光亮镀铜槽出来后,铜镀层呈镜面光亮。经过镀光亮镍后,发现光亮镍镀层表面出现白块、白条等疵病。当时给操作者的感觉是故障出在光亮镀镍工序。经查找,光亮镀镍工序没发现问题,故障仍未解决。起初为了维持生产,镀完亮镍后只得进行抛光,但过了几天后抛光也不行了,不得不查找电镀亮铜工序。     

毛遂自荐

求职内容：本人从事电镀工作20余年,一直在一线从事电镀工艺的开发与研制,熟练掌握不同金属底材（如铜、钢铁、锌合金、不锈钢、铝合金）等电镀与化学镀工艺,熟悉碱铜、酸铜、半光镍、冲击镍、多层镍、光镍、装饰铬、氰化物镀锌、氯化物镀锌等挂镀、滚镀工艺,能独立配制和维护镀液,能及时有效处理生产过程中出现的相关问题,有近10年水暖件电镀工作经验,有很好的敬业和团队精神,有良好的组织领导能力,现在宁波一家大型电镀企业任技术主管、工程师,欲求电镀技师或相关职位。     

电镀酸铜故障的分析、预防和解决措施

正铜-镍-铬体系中,硫酸铜电镀占着极为重要的地位,酸铜电镀的好坏直接影响电镀铜层的质量和相关机械性能,并对后续加工产生一定影响,因此如何控制好酸铜是电镀中重要的一环,酸铜也是很多大厂工艺控制较难的工序之一。笔者根据多年在电镀和技术服务方面的经验,初步总结如下,希望对酸铜电镀业者有所启发。酸铜电镀常见的问题,主要有以下几点:1镀层发花或发雾镀前处理不良,零件表面有油;清洗水或镀液中有油;阳极面积太小或太短;镀液中聚二硫二丙烷磺酸钠太多;有机杂质太多;光亮剂没有搅匀或十二烷基硫酸钠太少等会造成镀层发花或发雾。     

金刚石颗粒表面均匀电镀工艺研究

介绍在金刚石颗粒表面均匀电镀金属的工艺.以镀镍为例研究金刚石表面化学镀、电镀的工艺.设计了一种新型、多用途金刚石表面电镀的装置.用此装置也可在其他导电或者不导电的小颗粒表面电镀或者复合镀金属.在金刚石表面化学镀上一层导电的金属以后,再以滚镀的方式将电镀层加厚,可获得厚度在10～200μm的均匀金属镀层.同时还介绍了电镀后金刚石表面镀膜厚度的计算方法和电镀过程中要注意的一些问题,并简介了补镀的工艺和方法.     

铝经浸镀后如何电镀

为保证电镀层有良好的附着力,铝经浸镀后,应先在接近中性或弱碱性的溶液中预镀铜或镍,以防止浸蚀性强的电镀溶液将浸镀层破坏。预镀铜可在常规的焦磷酸盐溶液中进行。入槽后应在高电流密度下闪镀1～2min。预镀铜也可在氰化溶液中进行,其工艺规范如下:42g/L50～55g/L氰化亚铜(CuCN),氰化钠总量     

铝合金电镀工艺研究

铝及铝合金性质活泼，需经预处理才能进行电镀。采取二次浸锌的方法，在铝合金表面形成了一层锌层，再电镀暗镍、亮铜及装饰铬，得到了质量较高的镀层，并对实验过程进行了分析和讨论。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Thermodynamics Study on the Decomposition of Chromite with KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

Influence of Heat Treatment on Damping Behaviour of the Magnesium Wrought Alloy AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.     

Directional Growth of Tin Crystals Controlled by Combined Solute Concentration Gradient Field and Static Magnetic Field

A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.     

电化学噪声数据处理方法概述

综述了常见的电化学噪声数据处理方法,介绍了直流趋势剔除、统计分析、快速傅立叶变换(FFT)法计算功率谱密度(PSD)以及小波变换处理电化学噪声信号的基本过程,并阐释了各种数学处理及所得参数的物理意义。