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1.
用复合电镀方法在低碳钢基体上镀覆(Ni-P)-石墨复合镀层.研究了表面活性剂、石墨微粒的悬浮量及阴极电流密度对镀层中石墨微粒含量的影响.结果表明,当镀液中石墨微粒约为12g/L、搅拌速度120 r/min、温度为45℃、pH为4,镀层中石墨微粒含量最高.对镀层的表面形貌、耐蚀性、硬度、减摩性及耐磨性进行了测定,与Ni-P合金镀层相比,(Ni-P)-石墨复合镀层有良好的综合性能.  相似文献   

2.
Ag—MoS2共沉积过程研究   总被引:3,自引:0,他引:3  
本文采用滚镀法,由悬浮有MoS_2微粒的常规Ag(CN)_2~-镀液制备了Ag-MoS_2复合镀层。试验结果表明在Ag-MoS_2复合镀层的形成过程中,镀液中MoS_2悬浮浓度对镀层中MoS_2共沉积量有显著的影响;滚桶转速对它也有影响;而搅拌器转速几乎对它没有影响。在Ag-MoS_2共沉积过程中,第二吸附步骤——强吸附为速度控制步骤。  相似文献   

3.
本文是日本林忠夫先生在第12届世界表面精饰会议上发表的论文.从电镀镍、锌和铜溶液中可以获得红色、橙色或柠檬黄色的含蜜胺或丙烯-苯乙烯树脂萤光颜料的彩色复合镀层.当镀液中有机微粒的浓度不断增大,直至20克/升为止时,镍、锌镀层中有机粒子的含量亦随而不断增大.但当粒子浓度超过20~30克/升时,镀层中粒子的含量便持平.虽然剧烈搅拌镀液会促使粒子聚集在阴极上,但悬浮的粒子具有更高的动能,它会加速离子从阴极解吸.由于金属的沉积速度随阴极电流密度的升高而加快,而粒子同阴极表面的相互作用可以加速粒子在镀层中的共沉积.因此所得复合镀层具有荧光颜料和镀层金属组合而成的独特的色调.彩色复合镀层的耐磨性较差,为防止其脱色及提高彩色层的耐磨性,可在彩色复合镀层上再镀上一层光亮的Ni、Cr或Au层,也可涂上透明清漆.用复合镀的方法制得的含有机荧光颜料的彩色复合镀层可用于荧光金属板的生产以及作为装饰性彩色镀层.  相似文献   

4.
化学沉积新型复合材料的研究   总被引:4,自引:0,他引:4  
近年来,复合化学镀技术在开发新材料的探索中已为人们所关注。本文在酸性化学镀Ni-P合金的溶液中,加入T-稳定剂,以TiN微粒为分散剂,成功地制备出一种新型的(Ni-P)-TiN复合镀层。实验结果表明,TiN微粒在镀层中的含量与镀液中的悬浮量的关系呈Langmuir等温吸附线的形式。当维持TiN在镀液中的悬浮量不变,镀层中的TiN含量还与镀液的pH值及温度有关。经试验测定,(Ni-P)-TiN复合镀层的硬度随微粒含量的增加而增加,与化学镀Ni-P合金相比,具有更高的硬度值。经400℃热处理后,该复合镀层的硬度比硬铬镀层的硬度高。镀层耐磨性试验结果表明,(Ni-P)-TiN复合镀层比化学镀Ni-P合金镀层及硬铬镀层具有更好的耐磨损性能,极适于在高温条件下工作,这种耐高温磨损的性能,可以弥补硬铬镀层之不足。此外,本文对(Ni-P)-TiN复合镀层的耐磨性机理进行了初步的探讨。  相似文献   

5.
镶嵌镀是复合电镀的一种,镀复方法是在电镀溶液中,让高硬度的固体微粒沉降在需镀复的零件表面,通过电镀使大量的固体微粒固定在镀层表面,然后在不含微粒的溶液中进一步电镀,使微粒更牢固地在镀层之中,这样可使微粒在镀层中的含量高达50~70%。  相似文献   

6.
电沉积Ni-W-P基纳米微粒复合镀层的表面形貌和相结构分析表明:镀液pH的增大,镀层表面粗糙,但镀层较厚,稀土的加入能有效细化晶粒。(Ni-W-P)-SiO2、(Ni-W-P)-CeO2纳米微粒复合镀层在镀态时是非晶态结构,而(Ni-W-P)-CeO2-SiO2纳米微粒复合镀层在镀态时是混晶结构。热处理后的(Ni-W-P)-CeO2-SiO2复合镀层是晶态结构。Ni3P相的衍射峰加强,这说明随着热处理温度的升高,镀层的非晶态形态逐渐减弱,镀层逐渐向晶态转变。  相似文献   

7.
镍—金刚石复合电镀研究   总被引:2,自引:0,他引:2  
1 前言由于单一材料难以满足某些特殊要求,近年来迅速兴起的复合镀层,操作简单、易于控制、生产费用低、能耗少和原材料利用率比较高;与热加工法相比,复合镀层能在一定程度上赋予人们控制材料各方面性能的更大主动性。有关复合电镀研究的报导中,目前研究较多的是FeSiC,FeAl2O3,而对NiC(金刚石)研究得很少。本文报导的镍金刚石复合电镀研究主要包括:镀层内金刚石微粒含量、镀层耐磨性与镀液组成、工艺条件关系,力求为镍金刚石复合镀的应用提供实验和理论依据。2 实验2.1 镀液组成和工艺条件NiSO4·6H2O,gL280NiC…  相似文献   

8.
一、前言随着电镀技术的发展,人们正在寻找各种功能性镀层.以满足产品的不同技术要求.为了在产品表面获得功能性镀层,往往采用复合电镀方法.复合电镀是在电镀溶液中加入非水溶性的固体微粒,并使其与主体金属在镀件上共沉积的电镀工艺.本文所介绍的镍钴铬合金电镀工艺就是采用复合镀方法,在镀件表面得到具有高耐磨性和抗高温性的功能性镀层.它已在生产中取得了应用.  相似文献   

9.
陶瓷微粒的有效表面电荷密度在复合电沉积过程中的作用   总被引:1,自引:0,他引:1  
一、前言金属陶瓷镀层是国外近十几年来高速发展起来的材料科学中的一支新军,并在工程上得到了广泛的应用.它是把一种或多种不溶性的微粒均匀地悬浮于镀液中,以电镀(或化学镀)的方法使微粒与基质金属共沉积,从而形成的复合镀层.这种镀复的方法叫复合电镀.  相似文献   

10.
采用复合电镀技术制备了A u-S iO2纳米微粒复合镀层,研究了镀液中S iO2纳米粉体的浓度对A u-S iO2纳米微粒复合镀层结构与性能的影响,并用扫描电子显微镜(SEM)及能谱仪(EDX)对复合镀层进行了表面形貌和能谱分析,使用X-射线衍射仪(XRD)测试分析了粉体对金镀层组织结构的影响。结果表明,随着镀液中S iO2浓度的增加,镀层中S iO2含量与镀层硬度随之增加,在镀液中S iO2质量浓度为15 g/L时,两者出现最大值;另外S iO2粉体的加入细化了复合镀层的结晶结构。  相似文献   

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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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