共查询到20条相似文献,搜索用时 140 毫秒
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通过对数控电火花线切割加工中的电极丝直径大小的分析,探讨了电极丝直径大小对线切割加工的工艺影响,以及更换电极丝大小的方法. 相似文献
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Pai-Shan Pa 《Journal of Materials Engineering and Performance》2008,17(1):37-43
This study discusses the electrochemical smoothing and electrobrightening of medium or large holes beyond traditional drilling,
boring, turning, or extruding using both inserted and feeding electrodes of borer-rib type for several common die materials.
High electrical current is not required when the electrode of borer-rib type is employed to reduce the engaged area for large
holes. Traditionally, the hole polishing of a die requires a sequence of complicated premachining or some manual skill. In
the current experiment, six types of electrode are completely inserted and connected to both continuous and pulsed direct
current, while another six types of electrode are fed into holes using continuous direct current. The design features of the
electrodes are of major interest for effective electrochemical smoothing of holes. The controlled factors include the diameter
of the electrode as well as the chemical composition and concentration of the electrolyte. The experimental parameters are
current density, current rating, electrode design, die material, rotational speed, and feed rate of electrode. For the inserted
electrodes, the single-plate electrode performs better than the double-plate electrode, and the single-plate electrode with
half borer gives the best polishing effect. Pulsed direct current can slightly improve the polishing effect but at the expense
of increased machining time and cost. For the feeding electrodes, the electrode of one-side borer tip with half borer performs
the best polishing. It was also found that the electrobrightening after precise boring takes only a short time to make the
hole bright, while the electrochemical smoothing saves the need for reaming, making the total processing time less than that
required for electrobrightening. 相似文献
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采用离子选择性透过膜对铱金属氧化物pH电极进行表面修饰,提高了氧化物pH电极对氧化/还原性阴离子的抗干扰能力;研究了离子选择性透过膜修饰对电极的E-pH关系以及响应速度的影响;利用扫描电镜观察离子选择性透过膜的表面与截面孔径分布,优化了离子选择性膜的制备工艺;利用循环伏安法研究了氧化物电极在I^-溶液中的电化学行为;利用膜电位测定方法计算了膜内阴、阳离子透过系数t+,t-,探讨了离子选择性透过机理。 相似文献
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江建军 《稀有金属材料与工程》2003,32(3):201-204
研究了应用在空气-氢化物半燃料电池上的制备配套金属氢化物厚型电极烧结技术,将贮氢合金与细镍粉和一定的添加剂形成浆料涂覆在泡沫镍基体,测试不同烧结参数对贮氢合金电极的电化学性能的影响,烧结电极合金的电化学活化特性和高倍率放电能力与传统的粘结式电极有较大的提高,为设计适合电动车用高能量密度空气-氢化物燃料电池,分别选用冲孔镍箔带,冲孔铜箔带和铜编织网作为集流体进行比较实验。结果表明,选定冲孔铜箔带是适宜于设计空气-氢化物燃料电池用厚型氢化物电极。 相似文献
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采用丝束电极研究金属的缝隙腐蚀* 总被引:6,自引:0,他引:6
钟庆东 《中国腐蚀与防护学报》1999,19(3):189-192
采用丝束电极研究了铜在5%NaCl介质中的缝隙腐蚀行为。研究表明,铜发生缝隙腐蚀的过程中,缝隙内金属的腐蚀电位分布是不均匀的,不均匀的程度相差达数十毫伏。在缝隙腐蚀的初期,缝隙内金属腐蚀电位随着缝隙腐蚀的发生逐渐正移。随着缝隙腐蚀程度的加深,缝隙内金属的腐蚀电位发生负移,且逐渐均匀分布。这一过程与经典的金属缝隙腐蚀机理相吻合。 相似文献
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研究腐植酸作为改性剂在SnO2阳极制备过程中对其电化学性能的改善作用.采用扫描电镜、180°剥离实验和纳米压痕实验考察腐植酸对电极的影响.结果表明,腐植酸的添加能提高电极中颗粒的分散性能.各组分在腐植酸的作用下粘结得更加牢固,电极涂覆层在集流体上的黏附力增强.在腐植酸的作用下电极的抗变形性得到极大的改善.普通微米尺寸S... 相似文献
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In wire drawing, the wire is drawn through a series of dies sprayed with or immersed in an emulsion lubricant. The surface
conditions of the wire play a vital part in the mechanism of lubrication, and the conditions can be affected by electrochemical
parameters.
The electrochemical behavior of copper in selected emulsions was studied, and laboratory friction as well as pilot plant tests
were performed. Reduction of friction was detected at various potentials depending on the lubricant composition. Surface quality
of the wire was improved by the electrode control. 相似文献
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热镀锌双相高强度钢是适应汽车轻量化与安全性需要而刚刚发展起来的一种新型板材,强度高,抗腐蚀性能好,但点焊时电极磨损严重,不确定性大,对焊点质量造成很大影响.首先确定了点焊强度为600 MPa的热镀锌双相钢的焊接性范围,然后根据焊接性范围确定焊接工艺参数进行电极磨损试验.研究了电极磨损时的电极表面形貌、轴向磨损、端面直径磨损的变化规律,分析了不同电极磨损阶段的轴向磨损对端面直径磨损的贡献率.结果表明初始焊接阶段电极磨损速率较大,点蚀加剧了电极磨损与失效. 相似文献
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Oxygen reduction on teflon-bonded carbon electrode 总被引:3,自引:0,他引:3
1 INTRODUCTIONOxygenreduction (OR)inconcentratedKOHsolutionisanimportantprocessinvolvedinalkalinefuelcellsandmetal airbatteries .SomefundamentalstudiesofthekineticsandmechanismsofORincon centratedalkalineelectrolytesthoughrelativelylimit ed .Inalkalineelectrolytes ,OR proceedsbytwopathwaysasfollows :1) 4electrons (4e) pathwayleadingdirectlytoOH- ;2 ) 2electronspathwaywithhydrogenperoxideasintermediateorfinalproducts ,dependingonelectrodesurfacestatesuchastheoxy genadsorption ,oxideco… 相似文献