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在ZZn4-1锌合金中添加微量铈,能使其金属模铸造条件下的抗拉强度及布氏硬度有较在提高,并能有铲地改善其微观组织、细化晶粒。在压铸条件下,添加铈后,能使压铸件微观组织中无认是初生的η相和或共晶相均比没有添加铈的合金细小、弥散、均匀,从而使其力学性能及工艺性能得到提高,成品合格率大幅度增加。 相似文献
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研究了添加5种稀土元素对Ti0.26Zr0.07V0.24Mn0.1Ni0.33合金的微观结构和电化学性能的影响。结果表明,Ti0.26Zr0.07V0.24Mn0.1Ni0.33和Ti0.26Zr0.07V0.24Mn0.1Ni0.33RE0.01(RE=La,Ce,Pr,Nd,Gd)合金均由体心立方结构的BCC主相和少量六方结构的C14型Laves相组成;在合金中加入稀土元素,会使合金中两相的晶胞体积同时增大。添加5种稀土元素都可以改善合金电极的活化性能,而对合金电极其他性能的影响则各有不同,其中添加铈和镨可以提高合金电极的最大放电容量,而添加钕和钆能改善合金电极的循环稳定性。工作温度对合金电极的放电容量影响较大,过高的温度使其循环容量衰减加剧;而含稀土元素的合金电极在333K温度下放电容量达到最大值。稀土对合金电极的荷电保持率产生一定影响;镧、铈、镨的添加能够改善合金电极的倍率放电性能。 相似文献
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铅基稀土合金作为正极板栅的阳极膜性能 总被引:1,自引:0,他引:1
采用交流阻抗(EIS)、交流伏安(ACV)、循环伏安(CV)、腐蚀失重实验等方法研究了铅-钙-锡-铝-银合金中添加混合镧铈稀土在硫酸溶液中的阳极行为。 实验结果表明,混合镧铈稀土的添加能有效抑制阳极Pb(Ⅱ)膜的生长,降低Pb电极表面生成的Pb(Ⅱ)膜氧化膜电化学反应阻抗,改善阳极膜的导电性。 增强合金的耐腐蚀性能,并且增加析氧的过电位,抑制氧气的析出,降低电池的早期容量损失。 混合镧铈稀土的添加有利于提高电池的深循环寿命。 当镧铈混合稀土质量分数为0.5%时,各方面综合性能更优,效果更好。 相似文献
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Sc与Zr对Al-Mg-Mn合金力学性能和剥落腐蚀性能的影响 总被引:2,自引:0,他引:2
为了寻找Al-Mg-Mn合金力学性能和耐剥蚀性能的最佳组合,采用对比法探索Sc和Zr对Al-Mg-Mn合金力学性能和剥落腐蚀性能的影响,测定了含与不含微量Sc和Zr的Al-Mg-Mn合金板材在不同退火态的力学性能和剥落腐蚀性能,测量了它们的极化曲线.采用扫描电镜观察了合金的腐蚀微观形貌、用能谱仪分析了腐蚀产物的成分.采用光学显微镜和透射电子显微镜分析了合金的显微组织和力学性能、剥落腐蚀性能之间的关系.结果表明: 添加微量Sc和Zr能显著提高Al-Mg-Mn合金强度,改善合金强度和塑性的配合,而且Sc和Zr的添加没有引起合金耐剥蚀性能的明显下降.经过350 ℃/1 h退火的Al-Mg-Mn-Sc-Zr合金具有优良的力学性能和耐蚀性能组合.可通过添加微量Sc,Zr,减少Mg的含量,选择合理的退火工艺,使该类合金的力学性能和耐剥蚀性能达到理想组合. 相似文献
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AZ31和AZ61镁合金在模拟海水中的腐蚀电化学行为 总被引:2,自引:0,他引:2
应用极化曲线、电化学阻抗谱方法研究了两种Mg-Al-Zn系合金——AZ31和AZ61在模拟海水中的腐蚀电化学行为.根据两种镁合金在浸泡过程中腐蚀介质pH值的变化以及扫描电子显微镜对合金微观金相组织和腐蚀形貌的观察,讨论了镁合金的腐蚀机理及合金元素Al的含量对镁合金耐蚀性能的影响.结果表明,AZ61镁合金具有比AZ31镁合金更好的耐蚀性能,其原因主要是AZ61镁合金中Al含量较高使合金的微观组织结构更有利于耐蚀性能的提高. 相似文献
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非晶态Ni-Ce-P合金的共沉积与耐蚀性能 总被引:8,自引:0,他引:8
采用恒电位沉积、循环状安等方法研究了在水溶液中电沉积稀土合金的可能性 ,首次在含有CeCl3的弱酸性NaH2 PO2 镀液中获得了不同铈含量的Ni Ce P合金镀层 ,XPS、AES、XRD和SEM等实验技术表征了镀层的组成和结构 ,极化电阻和腐蚀电位的测试数据表明此镀层与Ni P无定形合金相比 ,具有更强的耐腐蚀能力 ,同时 ,讨论了沉积条件与镀层耐蚀性能的关系 ,结论是 :镀层中铈含量越高 ,其耐腐蚀性能越好 ,此外还对Ni Ce P的共沉积机理进行了初步探讨 ,指出在所研究的电沉积条件下 ,Ni Ce P合金共沉积可以用“诱导共沉积理论”合理解释 相似文献
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The electrochemical co-deposition of Al–Ce metallic protective coating with active inhibiting effect was performed for the first time using an ionic liquid as an electrolyte. Cerium was successfully co-deposited with aluminium on surface of Pt and AA2024 aluminium alloy forming uniform films with globular micro-structure and thickness up to 75 μm.Cerium was introduced into the aluminium coating as a potential corrosion inhibitor which can be liberated during sacrificial dissolution of the galvanic layer deposited on the alloy surface. The released inhibitor provides an additional active corrosion protection slowing down the corrosion processes in the defects. 相似文献
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用电化学方法研究了锌中掺入不同量Al、RE的锌合金在NaCl溶液中的耐蚀性能、硬度以及电化学行为的变化,并试图从合金结构上给予解释。 相似文献
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Ni-Co alloys were electroplated from sulphate electrolyte using addition agents including sodium gluconate,boric acid and cysteine on copper foil by the galvanostatic technique and ultrasound waves.The chemical composition,surface morphologies,crystalline structure and hardness of the Ni-Co alloys were studied using energy dispersive spectroscopy,scanning electron microscope,X-ray diffraction and Vickers testing method,respectively.The effect of current density and addition agents on the microstructure and morphology of Ni-Co alloys were examined.The appropriate concentration of additives and ultrasound waves were found to produce fine and smooth crystals leading to higher hardness of Ni-Co alloys.The microhardness of the Ni-Co alloys was varied between 4860–7530 HV.The surface morphology of coatings was changed from granular to fine due to using of gluconate,boric acid,cysteine and ultrasound waves.The mechanical properties of nanocrystalline Ni-Co alloys showed an increase of the hardness with the growing of Ni content in the alloy.The X-ray diffraction studies indicated that nanocrystalline structure was face-centred cubic for pure Ni and Ni-Co alloys with Co content in the range of 1–75 wt.%.A hexagonal closed-package structure was obtained for pure Co and Ni-Co alloys with the cobalt content with range of 75–99wt.%. 相似文献
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Wandong Li 《Surface and interface analysis : SIA》2022,54(6):631-641
The effects of 1 wt.% Ca or 1 wt.% Ca + 1 wt.% Ag addition and heat treatment on the corrosion behavior of Mg-7Sn (wt.%) alloy in 3.5 wt.% NaCl solution were investigated by electrochemical measurements and immersion tests. The alloys were characterized by optical microscope (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). It was found that all alloys were corroded by pitting corrosion and grain boundary corrosion and further corroded with time going. Loose layers of compounds, including Mg (OH)2, MgO, SnO2, and other compounds containing Ca and Ag elements, were calibrated on the surface of corroded Mg-7Sn-1Ca-1Ag alloy. The Ca addition improved the corrosion resistance of Mg-7Sn alloy due to the formation of relatively stable compounds containing calcium element and grains refinement. Furthermore, the solid solutioned alloys obtained a superior corrosion resistance due to the dissolve of eutectic Mg2Sn phase and homogenization treatment. However, the aging treatment is slightly detrimental to the corrosion resistance of Mg-7Sn alloys with the formation of Mg2Sn precipitates. In conclusion, the aged Mg-7Sn-1Ca-1Ag alloy exhibited a better corrosion resistance and a noticeable micro-hardness property compared with those of as-cast Mg-7Sn alloy. And this study provides an important idea for the research on the comprehensive properties of Mg-Sn alloys. 相似文献
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In this paper the effect of cerium addition in hypereutectic Al-Si alloys was studied. Casting method was used to produce Al-20Si with variation of Ce contents. The sample characterization studied was investigated by Optical Microscope, X-ray fluorescence and X-ray Diffraction. Vickers microhardness and wear test was carried out to study the influence of Ce towards the Al-20Si alloys. The addition of Ce in the Al-20Si alloys refined the Si primary phase as the Ce content increases. The results showed that the addition of 0.46 to 2.24 wt.% of cerium in Al-20Si alloys led to the formation of fine cells dispersed in the Al-matrix. These fine cells consist of a mixture of eutectic Si particles and intermetallic Al3Ce and CeAl1.2Si0.8 phase in Al matrix. The amount of rod- like intermetallic Al3Ce and CeAl1.2Si0.8 phase increases with increasing Ce content. The microhardness of Al-20Si alloys increases with the increase in Ce content. Addition of Ce up to 1.61 wt.% Ce improve the wear properties of Al-20Si alloy. 相似文献
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T. H. Muster D. Lau H. Wrubel N. Sherman A. E. Hughes T. G. Harvey T. Markley D. L. J. Alexander P. A. Corrigan P. A. White S. G. Hardin M. A. Glenn J. Mardel S. J. Garcia J. M. C. Mol 《Surface and interface analysis : SIA》2010,42(4):170-174
Rare earth (lanthanides) cations have demonstrated exceptional activity as cathodic corrosion inhibitors for aluminium alloys (AAs). While Ce is generally regarded as the most active, there have been reports of synergistic interactions between mixtures of rare earths, which show increased inhibitive activity. In this study a combinatorial experimental approach was used to evaluate the corrosion inhibition of four rare earth chlorides (Ce, La, Pr, Nd) singly and as mixtures. The estimation of corrosion currents using both potentiodynamic scans and electrochemical impedance spectroscopy (EIS) provided the quantification of corrosion inhibition. The results were then modelled to determine the best predicted inhibition activity. A partial least squares (PLS) regression indicated that the optimal response directly correlated with the amount of Ce present. From the regression analysis, Ce alone demonstrated the best inhibition activity, with the optimum mixture predicted to contain 100% Ce. The addition of La, Pr or Nd, was not observed to improve the inhibition activity. This study represents one of the first applications of combinatorial design to a fundamental question of corrosion inhibition. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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