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61.
Sodium hexanoate is proposed as corrosion inhibitor for copper when the metal is situated in an aggressive aqueous or gaseous environment. The efficiency of the inhibitor, measured by electrochemical techniques in the ASTM 1384 standard solution, depends on the hexanoate concentration. Copper foils immersed in a (0.1 M) sodium hexanoate conditioning bath, and later exposed to a strongly oxidizing gliding arc plasma in humid air, yield oxide layers, the thickness and the nature of which differ from the unconditioned samples since the voltammograms show no CuO at the surface. The organic salt thus limits the oxidation process induced by the gaseous species. The organic layer remains active for at least 30 min. For longer exposures, the salt begins to degrade to carbon dioxide, which makes the plasma treatment a useful tool to clean metallic surfaces. 相似文献
62.
介绍了一种廉价、简单易行的将阵列式排列的碳纳米管从石英基底上完整地剥离下来,从而得到无基底阵列式碳纳米管膜的方法。比较了生长基底对膜转移的影响。结果表明用抛光石英玻璃生长的阵列式碳纳米管膜转移到Al基底上的转移效率为80%,而普通石英玻璃上生长的碳纳米管膜转移到Al基底上的转移率为20%。去除基底后阵列式碳纳米管的电阻值表现出各向异性。 相似文献
63.
本文给出了五极彩色荧光象素管的基本结构及工作原理,基于发光亮度和工作电压之间的关系,讨论了它的周边电路的配置方法及彩色电视图像显示的驱动方案。最后介绍了1.6m2彩色图像显示系统样机,其垂直扫描采用双栅组合译码方式,因而扫描驱动器由N个减少到N/16+16个。 相似文献
64.
该文介绍了传统的超声波、渗透和射线等绝缘体探伤方法,分析了它们的优缺点,针对其缺点,提出了用安规测试仪探伤塑料制品的方法。实验中,设置安规测试仪为拉弧停止,试验检测合格品的最高耐受电压,高压扫描塑料制品,筛选出不合格品。其过程简单、高效、快速、准确而且经济适用,可以通过改造测试探头适应不同的塑料制品,能取得不错的检测效果。 相似文献
65.
TAILORING COMPONENT SUFACES for elevatedtemperature operations has been a goal of researchersduring the last century.Process and material selectionare the key factors for this development.In particularlythe latter can be described to have started with thedevelopment of stainless steels.Ni and Co based alloys,the superalloys,attended the increasing technologicaldemands for higher service temperatures(1).Morerecently the higher operating temperatures ofequipments,such as gas turbines,r… 相似文献
66.
Manual monitoring and seam tracking through watching weld pool images in real-time, by naked eyes or by industrial TV, are experience-depended, subjective, labor intensive, and sometimes biased. So it is necessary to realize the automation of computer-aided seam tracking. A PAW (plasma arc welding) seam tracking system was developed, which senses the molten pool and the seam in one frame by a vision sensor, and then detects the seam deviation to adjust the work piece motion adaptively to the seam position sensed by vision sensor. A novel molten pool area image-processing algorithm based on machine vision was proposed. The algorithm processes each image at the speed of 20 frames/second in real-time to extract three feature variables to get the seam deviation. It is proved experimentally that the algorithm is very fast and effective. Issues related to the algorithm are also discussed. 相似文献
67.
To improve the penetrating ability and the welding quality of keyhole plasma arc welding, a novel penetration closed-loop control system was established. In the system, welding current and plasma gas flow rate were selected as adjusting variables. The wavelet method was used to detect penetration status from welding arc voltage in real-time. The control strategy of one-keyhole-per-pulse was adapted to fulfill stable and high quality welding process. Experimental results show that the developed system can apparently increase the penetrating force of plasma arc and keyhole plasma arc welding is realized successfully in stainless steel with 10 mm in thickness. Moreover,the disturbances of gradual change and break change from 3mm to 6mm in thickness are come over due to the good response property of the developed system. 相似文献
68.
Aluminum coatings were sprayed on the substrate of steel Q235 by arc spraying. The test samples of Q235, Al coatings and Al coatings with seal coat were placed in box type electric resistance furnace at 400, 500,600, 650 ℃ when their oxidation behaviors were studied. And their oxidation kinetics curves were protracted. Microstructure, microhardness, bond strength and distribution of section elements were investigated by optical microscope(OM), Vickers microhardness instrument, electric tensile test machine and EPMA. Al coatings and Al coatings with seal coat can enhance the oxidation-resistance of substrate under 500 ℃. The latter has the best corrosion resistance. The coatings can't protect the substrate against oxidation above 600 ℃. After a long time corrosion there is enriched oxygen element at interface. 相似文献
69.
分析循环流化床锅炉水冷壁失效的原因,提出对炉管进行防磨喷涂的修复方案.比较几种不同喷涂技术的性能,介绍超音速电弧喷涂技术的特点、喷涂材质的选择及工艺流程.应用超音速电弧喷涂技术修复循环流化床锅炉水冷壁,经过2个100d长周期运行后,涂层完好均匀,厚度没有减薄. 相似文献
70.
研究了高纯度Ti3AlC2块体材料载流滑动下的摩擦磨损行为.试验在盘一块式载流摩擦磨损试验机上进行,以低碳钢盘为摩擦配对物,滑动速度为20~60 m/s,法向压强为0.4~0.8 MPa,通电电流为0,50,100 A.结果表明:Ti3AlC2具有良好的载流摩擦磨损特性,但摩擦系数和磨损率都比无电流时的大,且电流密度越大,摩擦系数和磨损率越大.在滑动速度为20 m/s,通电电流为100 A,法向压强为0.4 MPa的条件下,摩擦系数达到最大值0.35.在速度为60m/s,法向压强为0.7MPa,电流为100A的条件下,磨损率达到最大值8.3×10-6mm3/(N·m).与相同速度和压强但不通电情况下的摩擦系数0.17和磨损率2×10-6mm3/(N·m)相比,分别增大了大约1.1倍和3.2倍.观察和分析的结果表明:载流条件下摩擦系数的增大与Ti3AlC2摩擦面上TiC和Fe2.25Ti0.75O4及AlFeO3结晶相的生成有关,而Ti3AlC2磨损率的增大主要归因于放电电弧的烧蚀作用. 相似文献