锌钴合金镀层结构与耐蚀性研究

通过Ｘ射线衍射和Ｘ光电子能谱对钴的质量分数为０．００６￣０．００８的Ｚｎ－Ｃｏ合金镀层的组成、结构及腐蚀产物进行了分析，并与锌镀层进行比较，指出在Ｚｎ－Ｃｏ合金镀层中，钴使腐蚀产物致密稳定，并在腐蚀过程中形成富钴层，抑制了腐蚀过程。     

锌镍合金镀层盐雾腐蚀行为的研究

研究了锌镍合金电层的盐雾腐蚀行为，结果表明，１２％－１６％Ｎｉ镀层不仅５％红锈出现时间长，红锈扩展慢，而出现腐蚀增重。ＳＥＭ、ＥＰＭＡ、ＡＥＳ和ＸＲＤ分析表明，锌镍合镀层的高耐蚀性和腐蚀增重与生成粘附力强、绝缘性好的腐蚀产物ＺｎＣｌ２．４Ｚｎ（ＯＨ）２和２ＺｎＣＯ３．３Ｚｎ（ＯＨ）２有关，腐蚀产物还密积堵塞了镀层在腐蚀过程生成的大量微裂纹。     

锌—铁合金镀层耐蚀性探讨

采用扫描电子显微镜，Ｘ－射线衍射仪，分析了酸性氯化钾Ｚｎ－Ｆｅ合金电镀层的结构。讨论了纯化膜、镀层结构及镀层含铁量对镀层耐蚀性的影响。研究表明，由于钝化膜中微量铁的存在，使Ｚｎ－Ｆｅ合金镀层的耐蚀性优于纯锌镀层，而含（０．２￣０．３）％Ｆｅ的Ｚｎ－Ｆｅ合金耐蚀性最佳。     

电镀Ni-P合金镀层工艺研究

探讨了添加剂及工艺条件对镀层性能及镀层中磷含量的影响。根据实验结果,确定了电镀Ｎｉ－Ｐ合金镀液配方及工艺条件。在所规定的镀液配方及工艺条件范围内,可获得低磷（５％以下）镀层,中磷（６％－８％）镀层和高磷（９％￣１３％）镀层。     

银锑合金镀层中锑的分析

介绍了一种用溴酸钾氧化还原滴定法测定银锑合金镀层中锑含量的方法。结果表明这种方法操作简便，相对误差小，具有较强的实用性。     

沉降法电铸Ni—PSZ复全镀层

对究了沉降法电铸Ｎｉ－ＰＳＺ复合镀层工艺，对表面活性剂、阴极电流密度、搅掸间闲时间等工艺条件进行了摸索，结果表明，通过选择 表面活性剂和控制一定的工艺条件，可获得不同ＰＳＺ含量的均匀致密的复合镀层，镀层的硬度和高温氧化性能随着ＰＳＺ微粒复合量的增加而提高。     

化学镀Ni-P-B合金溶液的稳定性及镀层结构的研究

研究了化学镀Ｎｉ－Ｐ－Ｂ合金溶液的稳定性和镀层的结构。结果表明,增大镀液中硫酸镍、硼氢化钠、次亚磷酸钠浓度及溶液的ｐＨ值,会降低镀液的稳定性,而甲酸浓度增大则会显著改善镀液的稳定性。镀层中硼含量增加使磷含曦下降,且镀层结构由非晶向微晶转变。镀层硬度随硼含量增加而增大,４００℃热处理后镀层硬度具有最大值。     

电沉积非晶态铬—铁合金镀镀层研究

研究了从三价铬的硫酸盐体系中电沉积Ｃｒ－Ｆｅ合金镀层的工艺以及镀层的形貌、结构和性能。利用该工艺获得了厚度３０μｍ以上、铁含量（２０－３０）％的Ｃｒ－Ｆｅ合金镀层。实验结果表明，该镀层表面结瘤状，含有大量微裂纹，为非晶态结构，具有可热处理性。在６００℃下热处理１ｈ后硬度最高可达１４００ＨＶ以上，因此，可作为经济、耐磨性镀层使用。     

Solderability and its measurement

The ease with which molten solder wets and spreads on the appropriate metallic surfaces of electronic component assemblies during the manufacturing process is referred to broadly as the solderability of the component or printed circuit board. Two needs are evident: a traceable solderability measurement method giving reproducible data that predict process performance, and an agreed level of solderability which, for a given manufacturing process, will deliver an acceptably robust solder joint. This paper describes briefly present understanding of the mechanisms that govern solderability and the measurement methods most likely to prove acceptable to the electronics assembly industry     

Mechanical properties of the Sn-Zn eutectic alloys

The structure and mechanical properties of Sn-Zn unidirectionally frozen eutectic alloys have been examined over the growth range 5 to 4000mm h^–1. The structure is predominantly broken-lamellar below 750mm h^–1 but becomes increasingly fibrous at higher growth rates. The yield and ultimate strengths when tested in tension and compression were found to increase monotonically with growth rates up to 1000 mm h^–1 above which they assumed near constant values. This behaviour is attributed to some loss of axial growth at higher growth rates. The hardness measured on transverse sections increased over the entire growth rate range. Annealing at near eutectic temperatures followed by quenching increased the strength of alloys grown at less than 750 mm h^–1 and decreased that of those grown at higher rates. Similar behaviour was observed in selected Cd-Zn eutectic alloys. The increase in strength is attributed to solid solution hardening and the reduction to structural degradation during annealing. The Sn-rich matrix in this broken-lamellar eutectic appears to contribute significant strengthening to the composite.     

Solderability of Electrodeposited Fe-Ni Alloys with Eutectic SnAgCu Solder

Solderabilities of electrodeposited Fe-Ni alloys with SnAgCu solder were examined by wetting balance measurements and compared to those of pure Ni and pure Fe platings. Excellent solderability was found on the Ni-52Fe plating as both the wetting force and kinetics approached or exceeded those on the pure Ni. However, upon further increase in Fe content to 75 at. pct, the solderability of the alloy was severely degraded even though it was still better than that of the pure Fe plating. X-ray photoelectron spectroscopy showed that such a strong dependence of solderability on Fe content is related to the much thinner, incomplete oxide coverage of Ni-rich plating surface.     

Structure and properties of rapidly solidified Sn-Zn foils

We have studied the phase composition, chemical homogeneity, surface morphology, aging behavior, thermal stability, and grain structure of rapidly solidified Sn-Zn foils. The surface of the foils is found to have a cellular structure. The effect of solidification rate on the properties of the foils is examined. Data are presented on the microhardness of the foils as a function of zinc content. The microhardness data are interpreted in relation to the microstructure of the foils.     

Sn-Zn系无铅焊料的研究和发展

综述了Sn-Zn系无铅焊料的特性,以及工艺性能和服役性能等方面的研究进展,反映了当前研究中存在的问题及今后需做的努力.从熔点、毒性、资源和价格来看,Sn-Zn系无铅焊料是最佳选择.目前针对其润湿性、耐蚀性及疲劳性差等问题的研究已取得了很大进步.Sn-Zn系列仍是现在正在研制的各种无铅焊料中最有前途的一种.     

合金化元素对Sn-Zn钎料性能的影响

Sn-Zn无铅钎料因其低廉的成本、适合的熔点和良好的机械性能而受到众多研究者的高度关注.综述了Sn-Zn基无铅钎料的研究现状与存在的关键技术问题,分析了添加Bi、Ag、Cu、Al及稀土Re对Sn-Zn钎料熔点、润湿性、力学性能、抗氧化腐蚀及接头组织的影响,指出必须同时进行钎料的合金化、新型钎荆及改进钎焊工艺的研究,才能完成Sn-Zn基无铅钎科的工业实用化.     

锡锌系无铅钎料用免清洗助焊剂的润湿性评价

简要介绍了锡锌系无铅钎料的研究背景,针对锡锌系钎料容易氧化和润湿性差的缺点,研制了一种无松香无卤素的新型免清洗助焊剂.并且选用一种无机盐助焊剂和一种松香型助焊剂作为对比,进行了扩展率试验和润湿力试验以评价3种助焊剂的润湿性.试验结果表明,这种新型免清洗助焊剂能够提高Sn-9Zn共晶钎料的润湿性,并且助焊剂残留物少,无腐蚀,可免除焊后清洗工艺,符合环保要求,有利于促进Sn-9Zn无铅钎料在电子工业中的实际应用.     

Solderability of SnBi-nano Cu solder pastes and microstructure of the solder joints

The solderability of the Sn58Bi (SnBi)-nano Cu solder pastes and the microstructure of the solder joints were investigated. Experimental results indicated that the addition of the nano Cu particles in the SnBi solder paste shows limited effect on the solidus. The liquidus of the SnBi-3nano Cu solder paste was 1 °C higher than the SnBi solder paste. Solid Cu₆Sn₅ intermetallic particles formed in the SnBi-3nano Cu solder paste during the heating process. The Cu₆Sn₅ intermetallic particles decreased the mobility and wettability of the molten solder. Meanwhile, the Cu₆Sn₅ nano particles worked as nucleation sites for the formation of Bi grains and Sn–Bi eutectic phase during the cooling process and led to the grain refinement of the solder bulk. The SnBi-1nano Cu solder paste showed the smallest grain size in this research. Additionally, the SnBi-3nano Cu/Cu solder joint showed a eutectic microstructure of Sn–Bi system at the center of the solder bulk but a hypereutectic microstructure with polygon Bi grains near the margin in the solder bulk.     

铝及铝合金电镀高可焊性锡基合金工艺

重点对比了用浸锌、浸镍和磷酸阳极氧化两种铝及铝合金电镀前处理方法得到的锡基镀层的孔隙率，结合力、抗高温高湿性能、抗中性盐雾试验性能，分析了铝及铝合金锡基镀层在长期贮存过程中易变色、生霉、泛黑的原因，推荐了一种在铝及铝合金上电镀高抗变色性、高结合力、高可焊性的锡基镀层工艺。