首页 | 官方网站   微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 77 毫秒
1.
为提高深海电机密封罩的耐蚀性,采用电镀方法在其表面镀覆掺杂耐蚀纳米微粒的增强镍基复合薄膜。制定了电镀方案,剖析了其中涵盖的工艺要点,并考察了经镀膜防护处理的密封罩在模拟海水环境中的耐蚀性。结果表明:镀膜密封罩表现出较优的抑蚀阻蚀性能,表面腐蚀程度轻微。  相似文献   

2.
用高频脉冲复合电镀方法制备了(Ni-Co)-SiC复合镀层。研究了脉冲频率对镀层硬度及耐蚀性的影响。结果表明:随着脉冲频率的增加,复合镀层表面更加致密、均匀,硬度提高。在3.5%NaCl溶液和15%H2SO4溶液中,(Ni-Co)-SiC复合镀层的自腐蚀电位均发生正移,腐蚀质量损失速率变慢。与Ni-Co合金镀层相比,复合镀层具有较高的硬度和耐蚀性。  相似文献   

3.
AZ91D镁合金磁控溅射镀铝膜及其化学转化后的耐蚀性   总被引:2,自引:0,他引:2  
采用磁控溅射镀铝与化学转化复合处理的方法对AZ91D镁合金表面进行处理,制得复合处理膜层,并与单纯磁控溅射镀铝膜层的耐蚀性进行了比较。结果表明,磁控溅射所得铝膜层结构致密,铝膜层与镁合金基体界面形成混合过渡层。沉积铝膜后再进行阿洛丁化学转化所得膜层表面存在裂纹,化学转化膜与铝膜之间结合良好。磁控溅射铝膜层使镁合金的腐蚀速率加快。镀铝与化学转化复合处理所得膜层的腐蚀电流密度比镁合金基体低1个数量级以上,表明镀铝与化学转化复合处理可明显提高镁合金的耐蚀性。中性盐雾试验4h后,铝膜表面腐蚀严重;而复合处理膜层在试验24h后表面只出现少量的腐蚀,48h后只有5%的面积被腐蚀。  相似文献   

4.
以蒸馏装置常压塔顶冷凝器为对象,概述电镀工艺在石化设备腐蚀防护方面的应用。介绍电镀工艺原理及工艺流程,并对电镀工艺效果进行实验评价。结果表明:电镀Ni-Al复合镀层的蒸馏装置常压塔顶冷凝器内表面总体平整,表面状况良好,防腐性能较优。这反映出电镀工艺在增强石化设备表面防护效果方面具有优势且展现出美好的应用前景。  相似文献   

5.
高频脉冲电沉积镍-钴合金镀层的耐蚀性   总被引:3,自引:0,他引:3  
用电化学的方法研究了高频脉冲电镀镍钴复合镀层在NaOH溶液中的耐蚀性,采用扫描电镜观察了碱蚀前后镍-钴合金镀层的表面形貌,并测定了镀层在NaOH溶液中的极化曲线.结果表明:随着频率的增加,沉积速率提高,沉积层表面更加致密、均匀,在10%NaOH溶液中镍-钴合金镀层的腐蚀质量损失明显减小,腐蚀速率变慢;高频和直流电镀镍-钴合金镀层的极化曲线形状相似,高频脉冲电镀相比于直流电镀,更能提高镀层的耐腐蚀性.高频率对沉积层的细化可能有重要影响,并使镀层的耐蚀性提高.  相似文献   

6.
采用不同浓度的硫酸、磷酸溶液为腐蚀介质,研究了RE—Ni—W—P—SiC—PTFE复合电镀层于镀态下及经不同温度热处理后的腐蚀速率与阳极极化曲线,并与RE—Ni—W—P—SiC复合电镀层的阳极极化曲线进行了比较。结果显示,RE—Ni—W—P—PT—FE—SiC复合镀层在硫酸、磷酸溶液中的腐蚀规律基本一致,即在镀态或热处理条件下,随着硫酸或磷酸浓度的增加,其腐蚀速率上升,当硫酸浓度达到lO%~20%或磷酸浓度达到40%时,腐蚀速率最高;继续增加硫酸或磷酸浓度,复合镀层的腐蚀速率又降低。阳极极化曲线表明:200℃或500℃热处理后复合镀层具有较好的耐蚀性;该镀层热处理后耐蚀性要优于镀态下及热处理后的RE—Ni—W—P—SiC镀层。  相似文献   

7.
Q345钢材耐蚀性较差,在其表面电镀致密的Al2O3-Ni镀层可有效提高其耐蚀性,研究了电镀的电流密度对Q345钢镀层试样的耐蚀性影响。结果表明:电镀制备的Al2O3掺杂的Ni镀层可显著提高Q345钢的耐蚀性,电镀的电流密度最优值为2.5 A/dm2。基体的腐蚀电流密度为1.845×10-5 A/cm2。制备Al2O3-Ni镀层后,试样的腐蚀电流密度均显著下降。电流密度在2.5 A/dm2时,Al2O3-Ni复合镀层试样的腐蚀电流密度最小,为9.747×10-8 A/cm2。在盐雾腐蚀实验中,基体腐蚀速率最快,为12.081 g/cm2·h;电流密度为2.5 A/dm2时,Al2O3-Ni复合镀层...  相似文献   

8.
鉴于海工装备用Q390E钢的耐蚀性不理想,对其进行表面处理,在其表面制备Ni-SiO2纳米复合镀层。对Ni-SiO2纳米复合镀层的表面形貌、耐蚀性及腐蚀形貌进行了测试与分析。结果表明:与Q390E钢相比,Ni-SiO2纳米复合镀层表面更为平整,表面粗糙度降低21.2%,相同实验条件下腐蚀率明显降低,表面发生均匀腐蚀,腐蚀程度轻。Ni-SiO2纳米复合镀层的耐蚀性优于Q390E钢的耐蚀性,能起到腐蚀防护作用,提高Q390E钢的耐蚀性。  相似文献   

9.
采用不同浓度的盐酸、FeCl3溶液为腐蚀介质,研究了RE-Ni-W-P-SiC-PTFE复合电镀层于镀态下及经不同温度热处理后的腐蚀速率与阳极极化曲线,并与RE-Ni-W-P-SiC复合电镀层的阳极极化曲线进行了比较.结果显示,RE-Ni-W-P-PT-FE-SiC复合镀层于镀态下或经200、300、400、500℃热处理后,随着盐酸浓度的升高,其腐蚀速率先升高,当盐酸质量分数达到15%时,腐蚀速率达到极大值,进一步提高盐酸浓度,复合镀层的腐蚀速率有所下降;RE-Ni-W-P-PTFE-SiC复合镀层在镀态或200、300、400℃热处理后,随着氯化铁浓度的增加,腐蚀速率先增加,而后有下降的趋势,最后又有所上升,而在500℃热处理温度下,镀层腐蚀速率随FeCl3浓度的增加而一直缓慢增加.阳极极化曲线表明:200℃或500℃热处理后复合镀层具有较好的耐蚀性.  相似文献   

10.
为了提高X100管线钢的耐蚀性,在其表面进行Ni-WS2复合电镀.考察了电镀前后X100钢在60°C的饱和CO2模拟油田采出水中浸泡24 h内的腐蚀行为.通过扫描电子显微镜(SEM)观察了镀层腐蚀前后的表面形貌及厚度,通过X射线衍射仪(XRD)分析了镀层腐蚀前后的相组成,通过动电位极化曲线(PDP)和电化学阻抗谱(EIS)测试了有无镀层的X100管线钢的耐蚀性.结果表明:Ni-WS2复合镀层被腐蚀后表面依旧均匀、致密,腐蚀产物主要由Fe3C和FeOOH组成.有Ni-WS2镀层的X100管线钢浸泡在饱和CO2油田采出水中24 h内表现出比基体更强的耐腐蚀性能.  相似文献   

11.
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   

12.
13.
14.
15.
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   

16.
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   

17.
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   

18.
Inorganic/organic hybrid materials have considerable promise and are beginning to become a major area of research for many coating usages, including abrasion and corrosion resistance. Our primary approach is to prepare the inorganic phase in situ within the film formation process of the organic phase. The inorganic phase is introduced via sol-gel chemistry into a thermosetting organic phase. By this method, the size, periodicity, spatial positioning, and density of the inorganic phase can be controlled. An important aspect of the inorganic/organic hybrid materials is the coupling agent. The initial task of the coupling agent is to provide uniform mixing of the oligomeric organic phase with the sol-gel precursors, which are otherwise immiscible. UV-curable inorganic/organic hybrid systems have the advantages of a rapid cure and the ability to be used on heat sensitive substrates such as molded plastics. Also, it is possible to have better control of the growth of the inorganic phase using UV curing. It is our ultimate goal to completely separate the curing of inorganic and organic phases to gain complete control over the morphology, and hence optimization of “all” the coating properties. Thus far, it has been found that concomitant UV curing of the inorganic and organic phases using titanium sol-gel precursors afforded nanocomposite coatings which completely block the substrate from UV light while maintaining a transparent to visible light. Also, it has been found that the morphology of the inorganic phase is highly dependent on the concentration and reactivity of the coupling agent. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago, IL.  相似文献   

19.
20.
Ethanol and α-pinene were tested as attractants for large wood-boring pine beetles in Alabama, Florida, Georgia, North Carolina, and South Carolina in 2002–2004. Multiple-funnel traps baited with (−)-α-pinene (released at about 2 g/d at 25–28°C) were attractive to the following Cerambycidae: Acanthocinus nodosus, A. obsoletus, Arhopalus rusticus nubilus, Asemum striatum, Monochamus titillator, Prionus pocularis, Xylotrechus integer, and X. sagittatus sagittatus. Buprestis lineata (Buprestidae), Alaus myops (Elateridae), and Hylobius pales and Pachylobius picivorus (Curculionidae) were also attracted to traps baited with (−)-α-pinene. In many locations, ethanol synergized attraction of the cerambycids Acanthocinus nodosus, A. obsoletus, Arhopalus r. nubilus, Monochamus titillator, and Xylotrechus s. sagittatus (but not Asemum striatum, Prionus pocularis, or Xylotrechus integer) to traps baited with (−)-α-pinene. Similarly, attraction of Alaus myops, Hylobius pales, and Pachylobius picivorus (but not Buprestis lineata) to traps baited with (−)-α-pinene was synergized by ethanol. These results provide support for the use of traps baited with ethanol and (−)-α-pinene to detect and monitor common large wood-boring beetles from the southeastern region of the USA at ports-of-entry in other countries, as well as forested areas in the USA.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号