NIU Yan
,
F.GESMUNDO
,
WU Weitao
,
ZENG Chaoliu
,
F.VIANI
,
(State Key Laboratory for Corrosion and Protection
,
Institute of Corrosion and Protection of Metals
,
Chinese Academy of Sciences
,
Shenyang.110015
,
China)(Istituto di Chimica
,
Facolta'di Ingegneria
,
Universita'di Genova
,
Fiera del Mare
,
Pad.D
,
16129 Genova
,
Italy)Manuscript received 3 July 1995
金属学报(英文版)
The corrosion properties of a Co-15wt% Y alloy were studied in H_2-H_2S mixtures under a sulfur pressure of 10-3 Pa at 600-800℃ and of 10-2 Pa at 800℃ to examine the effect of Y on the resistance of pure cobalt to sulfur attack at high temperatures.The alloy is nearly single-phase.containing mostly the intermetallic compound Co17Y2 plus a little amount of the solid solution of Y in cobalt.At 600-700℃ and at 800℃ under 10-2 Pa of S2 the alloy forms multi-layered scales consisting of an outer region of pure cobalt sulfide,an intermediate region of a mixture of the sulfides of the two metals and finally an innermost layer of a mixture of yttrium sulfide with metal cobalt.At 800℃ under 10-3Pa of S2,below the dissociation pressure of cobalt sulfide, the alloy forms only a single layer composed of a mixture of metallic cobalt with yttrium sulfide.Pure Y produces only the oxysulfide Y2O2S, as a result of the good stability of this compound and of the presence of some impurities in the gas mixtures used The corrosion kinetics is generally rather complex and irregular except al 800℃under 10-3 Pa of S2.The addition of yttrium always reduces the sulfidation rate of cobalt, even though the formation of a continuous protective external layer of yttrium sulfide is never achieved.The internal sulfidation of Y in Co-15% Y is not associated with a depletion of Y in the alloy.This kind of diffusionless internal attack is typical of alloys with a very small solubility of the most reactive component Y in the base metal A.which restricts severely the Y flux from the alloy towards the alloy-scale interface.
关键词:
:cobalt-yttrium alloy
,
null
,
null
潘进兵
,
张士宏
,
张立文
,
刘劲松
,
张海渠
材料热处理学报
分析了TP2铜盘管在Junker炉中退火的传热过程,利用有限元软件MSC.Mare模拟了铜盘管退火过程的温度变化,研究了退火过程中铜盘管"热点"和"冷点"温度变化的规律.模拟结果表明:退火过程中铜盘管的温度分布是不均匀的,铜盘管中出现表面"热点"和中心"冷点";在退火时间上,"冷点"比"热点"要滞后一段时间.实测了TP2铜盘管在Junker炉中退火的温度场,测量结果与数值模拟结果一致.
关键词:
铜盘管
,
Junker炉
,
温度场
,
有限元
童志深
,
侯耀永
,
蒋生蕊
,
李明奇
,
吴大明
,
石玥
金属学报
<正> 本文研究温度对16MnRE钢在H_2S饱和水溶液中疲劳扩展速率的影响,是前文的继续。进一步检验以前所得的结果在不同温度下是否仍然正确;并测定腐蚀疲劳裂纹扩展的激活能,了解H_2S饱和水溶液腐蚀环境对16MnRE钢疲劳裂纹扩展影响的实质。 一、实验方法 16MARE钢热轧后,试验前未经热处理。其化学成分(wt-％)为
关键词:
Physica B-Condensed Matter
When the Schrodinger equation in quantum mechanics is replaced by the nonlinear Schrodinger equation to describe microscopic particles in nonlinear quantum systems, it has been verified that the nature of the particles differs considerably from those in quantum mechanics, where they are localized and have also wave-corpuscle duality due to the nonlinear interactions. In this case the influences of externally applied potentials in the nonlinear Schrodinger equation on the natures of the microscopic particles have been studied by a perturbation theory. The studied results show that the external potential can change the states of the microscopic particles, such as the positions, amplitude and wave forms, but cannot change the wave-corpuscle duality. In the meanwhile, we find further that the relationship between the external potential and change of positions of the particle satisfies the rule of motion of classical particles. Thus we know from this study that the kinetic energy term, ((h) over bar (2)/2m)del(2)phi, in the nonlinear Schrodinger equation can only make the microscopic particles have a wave feature, but the nonlinear interaction b vertical bar phi vertical bar(2)phi determines its corpuscle feature, their combination makes the microscopic particles have a wave-corpuscle duality, and the potential V((r) over right arrow, t)phi changes only the positions, amplitude and wave form of the particles. Therefore the nonlinear interaction plays an important role in determination of the wave-corpuscle duality of microscopic particles in quantum theory. (C) 2010 Published by Elsevier B.V.
关键词:
Microscopic particle;Schrodinger equation;External potential;wave-corpuscle duality;Nonlinear interaction;Quantum mechanics;schrodinger-equation
刘越
,
邰军超
,
丁莉
,
杨柯
复合材料学报
基于MSC.Mare软件平台,建立了含SiCP体积分数为12%的SiCP/2024A1复合材料热挤压轴对称刚-塑性热力耦合有限元分析模型.利用该模型对复合材料的热挤压过程进行模拟,分析了热挤压过程中的载荷一行程曲线和材料流动状态,讨论了模具温度及挤压速度对挤压载荷的影响.模拟结果表明,该坯料在挤压比为30:1、挤压温度为400～450℃、挤压速度为0.1～1.0 mm/s、挤压载荷为4.0×106～5.0×106N之间能够顺利挤出表面无缺陷的复合材料棒材.最后通过在700 t水压机上采用相同工艺挤出高质量的复合材料棒材验证该工艺的可行性.
关键词:
金属基复合材料
,
热挤压
,
有限元分析
,
热模拟
,
流线
