高硅铝合金无氰浸锌及镀层性能的测试

镀镍层质量是检验无氰高硅铝合金浸锌液性能的重要手段.利用扫描电镜(SEM)观察了试片在8种不同浸锌液中浸锌后所得浸锌膜以及镀镍后的表面微观形貌;采用X射线荧光能谱(XRF)测定了浸锌膜的厚度;用腐蚀膏试验和全浸试验(3.5%NaCl溶液)测定了镀层的耐蚀性;利用拉伸试验定量测定了镀镍层和基体的结合力.结果表明,高硅铝合金浸锌后,膜层薄且细致、均匀的浸锌层所得的镀镍层也细致均匀,结合力好,耐蚀性强.     

LY12铝合金表面预先活化处理化学镀镍工艺

研究了5种铝合金表面预活化处理工艺对随后化学镀镍层的光亮性及结合力的影响.确定了一种适用于LY12铝合金的碱性活化液配方,可代替浸锌处理.通过正交试验获得了化学镀镍的最佳配方及工艺条件为:硫酸镍25g/L,次磷酸钠22 g/L,柠檬酸钠30 g/L,UDIQ561稳定剂2 mg/L,UDIQ563复合添加剂0.2 mL...     

高硅铝合金表面处理的研究

本文介绍了含硅10～13％的铝合金的表面处理方法。采用三相直流与主波脉冲叠加的电源对高硅铝合金铸件进行氧化,并着黑色,获得了外观乌黑、平滑、光泽柔和、性能符合自行车使用要求的氧化膜;采用含铜与镍的锌酸盐浸锌液对高硅铝合金进行预浸渍,然后冲击镀铜,井在特殊的镀镍液中预镀镍后,即可按常规方法进行电镀,获得良好的结合力。     

用于高硅铝合金的无氰沉锌液

采用无氰沉锌技术在高硅铝合金表面制备沉锌层.通过正交试验得到无氰沉锌的最佳工艺配方为:NiSO4·7H2O 4 g/L,CuSO4·5H2O 2 g/L,FeCl3 1 g/L,ZnO 8 g/L,NaOH 60 g/L,配位剂25 g/L,调整剂1g/L.对采用最佳配方制得的沉锌层进行了孔隙率、结合力、沉锌电位-时间...     

铝和铝合金电镀前的浸锌处理

本文对铝和铝合金电镀前的浸锌工艺进行了研究。共研究了叁种浸锌液a,Bondal溶液:硫酸锌40 g/L、硫酸镍30 g/L、氢氧化钠120 g/L、氰化钾10 g/L,b,将上述氰化钾改成氰化钠,c,无氰浸锌液。结果表明,含氰化物的浸锌液效果较好,得到的浸锌层结晶细密,复盖性好。浸锌液的温度能影响膜的厚度与成膜速率,适当的成膜速率可以改善锌沉积层的附着力。对于含高硅或其它元素的铝合金来说,采用含氰化物的浸锌液,将会大大提高镀层的结合强度。     

喷射成形硅铝合金镀覆工艺研究

研究了喷射成形硅铝合金(CE11)材料表面化学镀镍和镀金工艺,使用电子显微镜(SEM)及能谱分析仪(EDS)分析了沉积过程中CE11硅铝合金表面形貌和沉积层化学成分,采用热震、高温烘烤、焊接试验等方法检测了硅铝合金样件的镀层质量。结果发现,CE11硅铝合金经氟化氢铵和硝酸混合溶液粗化、超声波去膜、浸锌、预镀镍后化学镀镍,可以获得结合力良好的化学镀层,镀金后能耐400°C烘烤而仍然保持很好的结合力,能够满足金锗、金锡等合金的共晶焊接使用要求。     

Study of deposition technology on spray formed silicon-aluminum alloy

研究了喷射成形硅铝合金(CE11)材料表面化学镀镍和镀金工艺,使用电子显微镜(SEM)及能谱分析仪(EDS)分析了沉积过程中CE11硅铝合金表面形貌和沉积层化学成分,采用热震、高温烘烤、焊接试验等方法检测了硅铝合金样件的镀层质量.结果发现,CE11硅铝合金经氟化氢铵和硝酸混合溶液粗化、超声波去膜、浸锌、预镀镍后化学镀镍,可以获得结合力良好的化学镀层,镀金后能耐400℃烘烤而仍然保持很好的结合力,能够满足金锗、金锡等合金的共晶焊接使用要求.     

镁锂合金双配位剂浸锌溶液的研究

为实现镁锂合金室温浸锌,以硫酸锌为主盐,选用3种有机酸盐配位剂两两组合,配制双配位剂浸锌溶液.通过电化学测试和扫描电镜分析,确定了双配位剂浸锌溶液优选配方及操作条件为:葡萄糖酸钠120 g/L,酒石酸钾钠60g/L,硫酸锌30 g/L,碳酸钠5 g/L,氟化锂3 g/L,室温,浸锌时间3 min.X射线衍射分析表明,浸锌层中呈晶态结构特征的主要是晶态Zn.在浸锌层上进行电镀镍处理,镀镍层具有较好的结合力和耐蚀性.     

活化工艺对铝合金化学镀镍的影响

通过开路电位测量分析了浸锌、钯活化、银活化和增强银活化对铝合金化学镀镍引发过程造成的差异.采用扫描电镜、能谱仪和结合力测试比较了上述4种活化方式对化学镀镍层表面形貌、元素组分和结合力的影响.结果表明,浸锌、钯活化、银活化和增强银活化引发铝合金化学镀镍的诱导时间分别约为50、5、10和2 s,钯活化和银活化的引发效率比浸锌高,所有活化方法下制得的镍镀层都有良好的结合力.采用增强银活化时镍镀层的表面形貌最佳.     

铝材表面化学镀镍技术

在常规铝材化学镀镍工艺基础上，提出一种在酸性化学镀镍前增加一道碱性化学预镀镍工艺的铝材表面化学镀镍新技术。介绍了其预镀镍的工艺流程与操作要点。研制了一种中等浓度的含镍、铁的多元合金浸锌液，并通过正交实验得出了浸锌最佳方案，确定了碱性化学预镀镍的最佳配方：25g／L硫酸镍，25g/L次磷酸钠，30g／L柠檬酸三钠，10g／L焦磷酸钠，10-15mL／L三乙醇胺，30g/L氯化铵。弯曲试验表明，镀镍层与铝基体结合强度很高；镀镍层SEM照片显示，镀镍层晶粒尺寸大小均匀，各晶粒间结合紧密，孔隙率低，耐腐蚀能力强。     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料，介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比，介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序，对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.