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梅钢电镀锡机组采用了目前世界上最新的MSA环保镀液体系,是世界上第一条MSA环保镀液与氧化铱不溶性阳极结合的电镀锡生产线.为满足产线连续运行,机组配备了离线制锡系统、镀液在线蒸发回收系统等.分析可溶性阳极和氧化铱不溶性阳极在MSA镀液中的应用差异,特别是不同应用环境中产生的差异化缺陷.重点介绍了梅钢镀锡生产线上的典型缺陷如酸斑、不润湿、低电流密度缺陷、高电流密度缺陷产生及消除方法. 相似文献
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针对某电镀锡机组最终成品板面铅含量影响因素进行了研究,围绕MSA镀液体系本身的极化能力、酸洗极板、锡粒中铅含量、Sn2+浓度等方面进行了量化的分析、探讨,并得出MSA镀液体系下批量稳定生产符合板面铅含量≤100 mg/kg的关键工艺参数控制点,即镀锡板表面铅含量的控制核心是减少镀液中铅元素的带入,对铅含量较高的原料进行管控可大幅减少镀液中铅含量;电镀液本身的极化能力对最终板面铅含量值的高低有着重大影响. 相似文献
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铬镀层具有优异的机械和抗腐蚀性能,传统六价铬电镀存在高毒、高污染等问题,三价铬绿色电镀工艺受到普遍关注,但铬镀层不能持续增厚和镀液稳定性差是关键瓶颈.文中研究了脉冲电流和镀液流动对铬电沉积的影响规律,发现两者均可促进电镀过程中生成的副产物向镀液主体的传递.然而,脉冲电镀会降低铬电沉积效率,镀液流动可以提高铬电沉积效率,并能促进铬镀层的持续增厚.在50 mL/min的镀液流动条件下,直流电镀60 min,可获得41 μm的厚铬镀层,沉积速率为0.68 μm/min,镀层表面平整致密. 相似文献
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Kinetics of solution hardening 总被引:3,自引:0,他引:3
U. F. Kocks 《Metallurgical and Materials Transactions A》1985,16(12):2109-2129
The flow stress of solution hardened single crystals and polycrystals is analyzed with respect to its dependence on temperature
and strain rate. An evaluation of literature data, especially at low temperatures and low concentrations in fcc alloys, reveals
that the interaction between dislocations and discrete, atomic-sized obstacles (or fixed clusters of them) cannot be responsible
for solution hardening. A “trough” model is favored in which the effect of the solutes is postulated to be equivalent to a
continuous locking of the dislocations along their entire length, during every waiting period. The macroscopic features of
this model are similar to Suzuki’s chemical-hardening model. It can also explain the strong interaction of solution hardening
and strain hardening at elevated temperatures, as well as basic features of dynamic strain-aging, in particular its strain
dependence.
This paper is based on a presentation made at the symposium “50th Anniversary of the Introduction of Dislocations” held at
the fall meeting of the TMS-AIME in Detroit, Michigan in October 1984 under the TMS-AIME Mechanical Metallurgy and Physical
Metallurgy Committees. 相似文献
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EJ Valente EC Lingafelter WR Porter WF Trager 《Canadian Metallurgical Quarterly》1977,20(11):1489-1493
Warfarin in solution is shown to consist of three interconverting tautomeric structures, two of which are cyclic diastereomeric hemiketals, while the third and minor component is the open-chain intermediate form. The configurations of all the tautomers as well as the major conformations of the cyclic tautomers are assigned. The assignments are supported by comparison with the chemical shift and coupling constant parameters of structurally fixed model compounds. 相似文献
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R Haydock 《Canadian Metallurgical Quarterly》1993,48(3):2172-2177
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Suggests that J. Platt's (see record 1974-20763-001) article on the Skinnerian approach to human problems poses a solution, setting up a superordinate authority, seen by G. Hardin (1968) as incongruous with a free society. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Comments on the article by P. R. Sackett, N. Schmitt, J. E. Ellingson, and M. B. Kabin (see record 2001-00625-002) which posed the dilemma of how to use tests to select for performance without excluding minority group members. The current author argues that society should challenge the premise that elite American universities should select students on the basis of promise of academic performance. It is maintained that psychologists should develop valid tests that accurately predict the qualities of creativity, good citizenship, participation in extracurricular activities, athletics, political correctness, and social activism. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献