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1.
锌-铁合金电镀层的黑钝化工艺   总被引:2,自引:0,他引:2  
介绍锌-铁合金电镀的黑钝化工艺;分析了影响钝化膜质量的因素有溶液组成、温度、钝化时间、水质等。指出以普通镀锌的黑钝化方法,在锌-铁合金镀层上很难获得理想的钝化膜;试验表明,锌-铁合金镀层的黑钝化膜的耐蚀性能优异。  相似文献   

2.
0前言 锌-铁合金镀层不仅防护性能优于普通镀锌与热浸镀锌层,而且还能提高对漆膜的结合力,具有良好的焊接加工性、抗蠕变性、易磷化性及抗蚀性。锌-铁合金镀层的磷化处理,能生成一种稳定的保护膜,提高涂层与基体镀层的结合力。  相似文献   

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信息集萃     
安徽马钢集团无铬钝化锌铁合金板填补国内空白日前,由马钢自主创新研发生产的700多吨无铬钝化锌铁合金板,经彩虹集团电子股份有限公司试用后,其产品性能完全符合欧盟要求,助推了民族品牌开拓国际市场。无铬钝化锌铁合金板的成功研发,填补了国内同类产品生产空白。无铬钝化锌铁合金板属于热镀锌产品,通过合金化处理在整个镀层上形成锌铁合金层,表面无锌花,以良好的焊接性、涂装性能和绿色环保特性在国际市场上受到普遍欢迎。[2006-10-26]http://www.lgmi.com/info-www/news/detailnewsb.asp?infoNo=279732华菱涟钢成功试制出无铬钝化镀锌板…  相似文献   

4.
在不含糖精和含有1g/L糖精的镀液中,采用脉冲电镀法在黄铜基体上分别制备出纳米晶镍-铁合金镀层。采用SEM,EDS,XRD和电化学工作站对镀层的表面形貌、名义成分、结构、极化曲线和交流阻抗谱进行测试。结果表明:当镀液中不含糖精时,镀层的自腐蚀电流密度为0.281μA/cm2,沉积镀层电阻为122 800Ω.cm2,且具有较明显的钝化趋势;当镀液中含有1g/L糖精时,镀层的自腐蚀电流密度为0.778μA/cm2,沉积镀层电阻为24 450Ω.cm2,且钝化趋势不明显。糖精的加入引起镀层晶粒细化及晶界体积分数增加,是造成纳米晶镍-铁合金镀层耐蚀性下降的原因。  相似文献   

5.
镍铁合金的微观结构及其在3.5%氯化钠溶液中的腐蚀行为   总被引:2,自引:0,他引:2  
采用极化曲线、电化学阻抗谱和腐蚀失重等方法,研究了含铁50%(质量分数)以下的镍铁舍金在3.5%NaCl溶液中的腐蚀行为.结果表明,所研究的镍铁合金均出现钝化行为.随着镀层中铁含量的增加,镍铁合金的耐蚀性能先减弱后增强.含铁36%的镍铁合金具有最好的耐蚀性.  相似文献   

6.
锌-铁合金镀层三价铬黑色钝化工艺的研究   总被引:1,自引:0,他引:1  
采用正交试验法对锌一铁合金镀层三价铬黑色钝化工艺进行优化,并研究了工艺参数对钝化膜外观和耐蚀性等影响.根据实验结果优选锌一铁合金镀层三价铬黑色钝化工艺.该工艺含有氯化铬、硝酸、硼砂、镍盐和磷酸根,采用有机羧酸作配位荆.该工艺能获得外观均匀黑亮、附着力良好的膜层,中性盐雾试验出白锈时间大于96 h.  相似文献   

7.
本文研究光亮锌铁合金镀层的电镀工艺.讨论了评价合金电镀液均镀能力的合理方法.并用扫描电子显微镜和X射线衍射仪分析了镀层的结构和相组成.用电化学方法研究了沉积机理,提出了添加剂的吸附模型.按本工艺可镀取含Fe5%左右的光亮锌铁镀层.银白光亮镀层钝化后具有美丽的天蓝色或金黄色外观,耐蚀性更佳,在某些场合可望作为防护装饰镀层.  相似文献   

8.
电镀锌合金的发展   总被引:3,自引:0,他引:3  
比较了锌-镍合金、锌-铁合金及锌镀层的性能,指出锌合金钝化膜的高温抗蚀性与二次加工后的抗蚀性比锌镀层有很大提高,介绍了电镀锌-镍合金与电镀锌-铁合金的工艺,并突出介绍其工艺特点,综述了电镀锌合金及其钝化工艺在近年来的发展状况。  相似文献   

9.
为了提高Zn-Fe合金镀层耐蚀性,采用非银盐发黑剂,结合磷化工艺,并加入适当的添加剂及辅助成膜剂,研制出了一种新的Zn-Fe合金镀层黑色钝化工艺。该钝化液中铬酸含量低,污染小,且化学性能稳定,使用寿命长。详细研究了钝化液中各组分对钝化膜成膜及其耐蚀性的影响,从而确定了最佳的钝化液组成。研究结果表明,采用该种钝化液获得的钝化膜油黑发亮,色泽均匀,耐蚀性及耐磨性好,附着力强。  相似文献   

10.
向瓦特型镀镍液中添加硫酸亚铁并改变铁、镍离子的质量浓度比,在紫铜表面制备了铁的质量分数不同的镍-铁合金镀层,相应地命名为镍-14.52%铁合金镀层、镍-22.18%铁合金镀层、镍-30.70%铁合金镀层、镍-42.73%铁合金镀层。比较了四种镍-铁合金镀层的织构和性能。结果表明:铁的质量分数是影响镍-铁合金镀层的织构、热膨胀性、显微硬度和抗拉强度的重要因素;镍-30.70%铁合金镀层具有较高的显微硬度和抗拉强度;镍-42.73%铁合金镀层具有较小的平均线膨胀系数。  相似文献   

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12.
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.  相似文献   

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14.
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.  相似文献   

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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.  相似文献   

18.
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.  相似文献   

19.
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.  相似文献   

20.
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。  相似文献   

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