锡镀层表面抗氧化剂及其使用工艺

本发明涉及一种锡镀层抗氧化剂，其主要是由有机钝化缓蚀剂、辅助缓蚀剂、pH稳定剂混合而成的透明无悬浮物液体。钝化缓蚀剂的结构必须有N—H键或至少有一个其他形式的N键，包括唑类、噻唑类；辅助缓蚀剂为无机盐，包括钠盐、钾盐；pH稳定剂为钠盐。使用pH值8—10之间添加100mL／L上述抗氧化剂，     

温度循环条件下镀层表面的Sn须生长行为

采用TO220封装的电子元件,研究了在温度循环条件下,元件Cu引脚上纯Sn镀层的Sn须生长行为.研究发现,Sn须在温度循环条件下的生长呈现出较高速率、较高密度、较一致长度的特点.随着温度循环次数的增加,Sn须密度和长度不断增加;与此同时,镀层表面Sn须的附近区域出现凹坑.研究表明,Cu-Sn金属间化合物的生长速率很快,使得镀层内部压应力增大,Sn须生长驱动力增加;同时,不同材料热失配产生的低周疲劳热应力,为Sn须的生长提供了额外的驱动力.此外,交变的热应力更容易破坏表面氧化膜促进Sn须的生长.满足应力条件和取向条件的晶粒首先发生Sn须生长,高密度的Sn须生长诱发部分晶粒发生向内的变形,在镀层表面形成大量的凹坑.     

锡钴合金镀层耐蚀性探讨

采用扫描电子显微镜、Ｘ－射线衍射仪,分析了焦磷酸钾锡钴合金电镀层的结构。比较了镀层和缎铬的性能。研究表明,锡钴合金颜色、抗蚀性和镀铬层基本相似,含钴２０％左右其效果最佳     

无铅镀层锡晶须问题的研究进展

全球电子封装行业的无铅化趋势,使得镀层锡晶须自发生长的问题变得十分突出。由于晶须的导电性可以引起高密度封装引脚之间短路,从而使电子产品失效甚至引发灾难性的事故,因此研究并阐明锡晶须生长机理、探索有效抑制锡晶须生长的手段、寻找合适的锡晶须生长加速实验方法评估电子产品的可靠性,成为当前亟需解决的问题。本文从锡晶须问题的由来,锡晶须的危害、锡晶须生长的机理、影响锡晶须生长的因素、抑制锡晶须生长的方法和锡晶须生长加速实验方法等几个方面,对锡晶须问题尤其是近年来这方面的研究进展作一简要评述,并提出一些需要研究的课题。     

移相器组件铝腔体内的锡铅镀层质量检测

锡铅合金镀层因具有低共熔点,良好的耐蚀性广泛用于电子元器件产品中,以增加元器件的焊接性能。通过对三个不同单位的用于移相器开关组件铝腔体的Sn-Pb镀层为研究对象,采用微观分析SEM-EDS的结合手段分析镀层的表面形貌和成分,评价镀层的表面孔隙情况以及成分含量,以判断产品是否符合要求。     

碳纳米管/锡铅合金复合镀层的滑动磨损特性

锡铅合金用作轴承材料减摩性能良好,但承载能力不足,引入碳纳米管改性可望改善这这种状况,以往对此研究不多。通过复合电沉积方法制备出碳纳米管/锡铅合金复合镀层,采用盘销式相对摩擦磨损试验机研究了不同工艺参数下的碳纳米管/锡铅复合镀层与普通锡铅镀层的摩擦磨损性能。结果表明:在润滑状态下,不同载荷下碳纳米管/锡铅复合镀层的摩擦系数均低于普通锡铅镀层;在同一载荷下随着碳纳米管含量的增加,复合镀层的摩擦系数出现先降低后升高的趋势,当碳纳米管含量为2 g/L时,摩擦系数出现最小值,耐磨性能最好;在不同载荷下,碳纳米管复合镀层的磨损量都小于普通锡铅镀层的磨损量,随着碳纳米管含量的增加,磨损量也出现先减小后增大的现象。     

电子和光子封装无铅钎料的研究和应用进展

对目前国内外电子和光子封装用无铅钎料研究和应用的新进展和发展趋势进行了回顾、评述和展望,重点评述了无铅钎料的种类和钎焊接头的力学性能、封装结构的可靠性和耐久性,以及目前出现的影响电子封装可靠性的一些新问题（如电迁移和锡须问题）．对光子封装钎料和相关钎焊工艺也进行了简要评述．最后,探讨了电子和光子封装无铅钎料及其可靠性和耐久性研究的发展趋势．     

钢铁表面Ni-P-SiC复合镀层的表面形貌及组成

运用SEM,AES和XPS分析了Ni-P-SiC复合镀层的表面形貌及组成,研究显示：Ni-P-SiC镀层的组成为（％）Ni51.01,P29.38,Si3.64,C3.88,O0.75和Fe10．08时,镀层腐蚀能力 较强。     

钛合金Ni-P化学镀层中磷含量对镀层形貌、组构及耐磨性能的影响

为了探讨钛合金表面Ni-P化学镀层中磷含量对镀层组构、耐磨性及机理的影响,在TC4钛合金表面制备了不同磷含量的Ni-P化学镀层。借助扫描电镜(SEM)、能谱仪(EDS)和X射线衍射仪(XRD)观察了Ni-P化学镀层的形貌和组织结构,测试了其硬度、磨损量和摩擦系数;探讨了Ni-P化学镀层中磷含量对镀层硬度和耐磨性的影响,初步分析了磨损机理。结果表明:随着Ni-P化学镀层中磷含量的增加,镀层的瘤状结构和晶界逐渐减少,晶粒尺度逐渐增大,并由晶态向非晶态转变;镀层的硬度降低,磨损量增加,摩擦系数降低;低磷Ni-P化学镀层表现出磨料磨损和轻微的黏着磨损特征,中磷和高磷Ni-P化学镀层表现出严重的黏着磨损和磨料磨损特征。     

不同锡含量Ni-Sn-P化学镀层的制备及性能

为了制备不同锡含量的Ni-Sn-P化学镀层并研究其性能,利用X射线荧光光谱等分析了主盐、还原剂、配位剂浓度对镀层锡含量的影响,考察了热处理前后锡含量对镀层耐蚀性和显微硬度的影响.结果表明:镀液中氯化锡浓度在20～40 g/L时,随着其浓度的提高,镀层中锡含量增加,继续增加其浓度时,镀层中锡含量下降;提高柠檬酸三钠和乳酸的浓度有利于锡的沉积,而提高酒石酸钾钠、次磷酸钠的浓度对锡含量的增加不利;热处理后,镀层的腐蚀速率和孔隙率提高;锡含量提高时,镀态镀层和热处理镀层的腐蚀速率和孔隙率显著下降;锡含量在2.5%～12.1%时,镀层热处理前后的显微硬度均在550～650 HV之间,且随着锡含量的增加,镀层硬度增加;镀态镀层热处理后,显微硬度有小幅提高.     

涂料附着力测定的不确定度评定

根据JJF1059-1999标准,以环氧富锌底漆与聚氨酯面漆配套样板、吸波涂料样板以及环氧云铁厚浆底漆试柱附着力的测量为例,对GB／T5210-2006标准规定的3种试验方式分别进行了不确定度评定。结果表明：不同试验方式的测量不确定度是不同的,为在实际检测时选择适合的试验方式提供了依据。     

涂料粘度（涂-4法）测量的不确定度评定

根据JJF1059-1999《测量不确定度评定与表示》的规定对GB1723-1993《涂料粘度测定法》中涂-4粘度计法的测量结果,结合检测工作中的经验分析了测量不确定度的来源及影响因素,建立了相关的数学模型,并对其不确定度进行评定。     

无铅易切削镁黄铜的组织与性能

采用熔铸、挤压、拉拔的方法生产出了以镁代铅的环保型易切削黄铜材.对易切削黄铜的微观组织进行了观察,并对其力学、化学和切削性能分别进行了研究.结果表明:镁黄铜晶内和晶间有白色和黑色的球状第二相粒子分布,该粒子为金属间化合物,具有脆而不硬的特点,对提高合金切削性能有利.半硬态镁黄铜的抗拉强度为550 MPa,屈服强度为280 MPa,延伸率为16.30%,断面收缩率为32.4%.从切削过程中切削力的大小以及切屑的形貌、大小可以判断,镁黄铜的切削性能接近于C3604铅黄铜.镁黄铜在酸中和盐中的耐蚀性均较好,比较而言耐盐性要好一些.     

Microstructure of TiB Whisker Reinforced Ti Matrix Composite

The composite of Ti matrix with TiB whisker reinforcement has been successfully fabricated. The content of TiB whisker in Ti matrix can reach about 30 vol. pct. Metallographic examination,morphology and microstructure of TiB whisker, interface structure between TiB whisker and Ti matrix were investigated using optical microscope, SEM, TEM and HREM technology. The diameter distribution of TiB whisker is from 0. 1 μm to 3.5 μm and the aspect ratio of TiB whisker is from 10 to 20. The cross-section of whisker is generally polygon. Because of good compatibility between TiB whisler and Ti matrix it is identified that there is no obvious interaction of Ti matrix with Ti B reinforcement and TiB whisker reinforced Ti matrix composites have excellent elevated properties.     

量值比对结果评价分析和风险控制

量值比对用来考察各实验室计量标准复现量值的一致的程度,考核实验室环境条件、人员水平、检测方法及数据处理等方面的实际水平和能力,量值比对通常用En值来评价参比实验室给出的测量结果.正确认识比对结论,准确评价比对结果,控制比对风险,是参加量值比对时需要引起足够重视的问题.     

B-Cr-Ti共渗层的显微组织与性能

本文用金相显微分析、电予探针和 X 射线衍射分析等方法对五种钢材的 B-Cr-Ti 共渗层进行了化学成分、相结构及显微组织分析。同时,对 B-Cr-Ti 渗层的性能进行了研究。     

Hot-Dip Coating of Lead-free Aluminum on Steel Substrates with Ultrasonic Vibration

Hot-dip coating has been practically employed in manufacturing zinc alloy coated steel sheets.However,it is difficult to coat aluminum alloy on a bulky steel substrate without sufficient preheating,because a rapidly solidified layer containing gas babbles is formed on a substrate surface.A variety of iron-aluminides are also formed at the interface of a steel and aluminum hot-dip coating system,which is the main difficulty in joining of steel with aluminum.Ultrasonic vibration was applied to a steel substrate during hot-dip coating of aluminum alloy to control a rapidly solidified layer and a brittle reaction layer.Hot dipping of columnar steel substrates into molten aluminum alloy （Al-2.7 mass fraction Si-4.6 mass fraction Sn） was carried out through the use of a Langevin oscillator with resonant frequency of 19.5 kHz.The application of ultrasonic vibration is quite effective to control a rapidly solidified layer and a surface oxide layer from a substrate surface by the sonocapillary effect based on a cavitation phenomenon,so that the intimate contact is achieved at the beginning of hot-dip coating.The application of ultrasonic vibration to hot-dipping is effective to control a reaction layer with less than 5 #m in thickness.An impact test exhibits that the good adhesive strength is approved in hot-dipped aluminum coatings with a thin reaction layer of approximately 5μm.     

Morphology and Microstructure of Sputtered Superalloy Coating

The morphology and microstructure of magnetron sputtered coating of superalloy K38G on cast al-loy K38G have been investigated by means of SEM, TEM and XRD. The results indicate that thesputtered coating is identical to the substrate in chemical composition but it is composed only of γphase without γ'. The sputtered superalloy coating presents columnar structure and the grain size isin the range of 20-100 nm. There are a great number of planar defects such as stacking faults andmicrotwins in the coating. The morphology and microstructure of the sputtered coating may haveclose relation to the remarkable increase of oxidation resistance of the coating.     

Preparation and Tribological Properties of Ni-P Electroless Composite Coating Containing Potassium Titanate Whisker

Nickel-phosphorus （Ni-P） composite coatings containing potassium titanate （K2Ti6O13） whiskers （PTWs） were prepared by electroless plating. The surface morphology and component of coatings were investigated by scanning electron microscopy （SEM） and energy dispersive X-ray spectroscopy （EDX）, respectively before and after wear test. The tribological performance was evaluated using a pin-on-disk wear tester under dry conditions. It is found that the Ni-P-PTWs composite coatings exhibit higher wear resistance than Ni-P and Ni-P-SiC electroless coatings. The favorable effects of PTWs on the tribological properties of the composite coatings are attributed to the super-strong mechanical properties and the specific tunneling structures of PTWs. The PTWs greatly reinforce the structure of the Ni-P-based composite coatings and thereby greatly reduce the adhesive and plough wear of Ni-P-PTWs composite coatings.