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Surface Modification of a MCFC Anode by Electrochemical Alloying 总被引:1,自引:0,他引:1
l introductionMolten carbonate fuel cell (MCFC) is believed to be one of the most promising new energy conversion device that converts chemicalenergy in fossil fuels into electricity [IM]. It isa highly efficient and environmentally cleansource of power generation. Ill MCFC technology the most frequently used anode material isporous nickel. As an anode material, the performance of porous nickel is relatively satisfactory, hilt it still needs some improvemellts, especially in its corrosion … 相似文献
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研究了Nb对燃气轮机用镍基合金时效硬化曲线的影响。结果表明,无Nb和含Nb合金均在750℃×16h时效达到最佳时效硬化效果。含Nb合金在所有温度下的时效硬化曲线都高于无Nb合金。Nb主要是通过使γ数量增加、γ颗粒尺寸增大、γ相成分复杂化以及使晶粒细化和晶界M23C6呈链状分布等起到硬化作用的。但含Nb镍基合金不宜在高温下长期使用,以避免无时效硬化作用的η相析出。 相似文献
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1 INTRODUCTIONNiTi basedshapememoryalloysarethemostimportantcommercialshapememorymaterials .InNi richNiTialloys ,some precipitatessuchasNi14 Ti11,Ni3Ti2 andNi3Ticanbeobservedduringaging[1,2 ] ,whichcanimprovethesuperelasticityofalloys[3] .Inmanycasesthealloyingorthermomechanicaltreatmentsareusedinordertochangethetempera turerangeofSMEmanifestation .TernaryadditionofniobiumtoNiTiwasreportedtosignificantlywidenthethermalhysteresisofthemartensitetransforma tion[4 ] .Asantypicalexample… 相似文献
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研究了Ni+Nb为中间层对Ti2AlNb与GH4169真空扩散连接反应动力学过程.结果发现:主要影响接头剪切强度的Ni6Nb7层厚度存在一个最佳值,通过最小二乘法拟合得最佳厚度为3.36 um.根据修正的有效生成热理论和有效吉布斯自由能理论均预测Ni6Nb7为Ni-Nb固-固界面反应的初生相,因此在连接过程中Ni6Nb7相的出现是不可避免的.由于Ni6Nb7的生长速度低于Ni3Nb,因此可以通过优化工艺参数来控制Ni6Nb7层的厚度来提高接头的力学性能.通过Ni6Nb7层最佳厚度和生长速率计算可得知最佳保温时间约为49.5 min,实验结果表明,连接温度1050℃,压力20MPa,保温时间为49.5 min时,Ni6Nb7厚度为3.37μm,接头剪切强度达到468.2MPa. 相似文献
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The electroless Ni-W-P coatings on polyoxymethylene(POM) were prepared. The POM was pretreated by hot spraying Al powder on it. Before the electroless Ni-W-P deposition, the POM with Al coating was flash plated in alkaline bath. The mechanism of Ni-W-P deposition was studied and the technology was optimized. The XRD analysis shows that the "as-deposited" Ni-W-P plating has mixed crystalline structure. The hardness value of deposits is more than HV700. The abrasion resistance of deposits is six times more than that of POM. Bending test was used to determine the cohesion between the deposits and the substrates. SEM was used to study the behavior of surface abrasion and interface bonding condition. The reason for the excellent cohesion was interpreted. 相似文献
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根据电化学加工极间间隙电势分布的拉普拉斯方程,本文提出了一种阴极设计算法:误差调整法。该算法的实现主要采用了Ansys有限元计算软件。计算结果表明:该法计算迭代次数较为适当,对于精度要求不高的电化学加工阴极设计,基于Ansys的辅助阴极设计有效可行。 相似文献
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新的阴极焙烧炉设计,改变传统的配置方式,充分利用有限空间扩大焙烧炉装炉能力;改变烟道连通方式,提高系统焙烧过程监控水平,控制挥发分的燃烧,有效地减少了制品的焙烧裂纹,产品合格率大幅上升;改进设计带来了增产、节能、改善工作环境、提高产品质量的良好效果。 相似文献
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Xinhua Wang Changyao Wang Changpin Chen Qidong Wang 《Journal of Alloys and Compounds》2006,420(1-2):107-110
In this paper, we deduced an empirical equation for predicting the stabilities of the hydrides of AB5-type compounds with the consideration of the effects of geometrical factor and electric factor. The theoretical curves derived from this equation are in good agreement with the test results of La1−xCaxNi5, Ml1−xCaxNi5 and La1−xCexNi5 compounds. With this model, we can easily interpret the phenomenon that the initial partial substitution of R by Ca in R1−xCaxNi5 (R is rare earth metal) compounds cause an increase of hydrogen desorption pressure to a maximum value, whereas in the range of larger Ca content x the hydrogen desorption pressure decreases with increasing x. 相似文献
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对不同的变形条件下Ni47Ti44Nb9合金的DSC相变曲线进行测定,分析了它们与变形量的变化规律。结果表明,变形量越大,相变热焓随之有所增加。 相似文献
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自蔓延高温合成Ti44Ni47Nb9合金过程中的燃烧界面成分与组织 总被引:4,自引:0,他引:4
采用燃烧波淬火法,获得了Ti44Ni47Nb9三元系的燃烧波熄灭界面。通过对该界面及面前后的组织形貌分析和相组成变化的分析,弄清了该三元系合金在自蔓延高温合成中的结构和形成机理。 相似文献
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采用金相显微镜、电子背散射衍射(EBSD)、维氏硬度计、差示扫描量热仪(DSC)和电阻-温度测量仪,研究了不同温度(300~900 ℃)退火1 h对Ni47Ti44Nb9合金冷轧板的微观组织、力学性能及相变行为的影响。结果表明,当热处理温度低于400 ℃时,材料硬度值变化不明显,合金未发生马氏体相变;当退火温度为400 ℃时,硬度值显著下降,合金开始发生再结晶;当退火温度在500~800 ℃时,随着温度升高,再结晶越充分,马氏体相变温度越高,相变焓增加。800 ℃退火1 h后,合金基本完成再结晶,晶粒尺寸约11 μm;当退火温度升高至900 ℃,晶粒出现长大现象,晶粒尺寸增加至20 μm。 相似文献
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仿生机器人运动稳定性的研究进展 总被引:1,自引:0,他引:1
对国内外仿生机器人运动稳定性的研究现状做了概括和总结,从研究模型的改进、非结构环境下稳定性判据、非线性系统下稳定性判据、多指标稳定性判据的研究等方面,阐述了其未来的研究重点和方向. 相似文献
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Zijun Liao Jiankai Kang Qi Luo Caifeng Pan Jiangdong Chen Xiaolong Mo Hanbo Zou Wei Yang Shengzhou Chen 《金属学报(英文版)》2022,35(6):985
Lithium-rich manganese-based oxides have the advantages of high discharge specific capacity, so they are potential candidates for advanced lithium battery cathode materials. However, they also have drawbacks to be solved such as serious irreversible loss of capacity and voltage decay in the cycling process. Surface coating method was used in this paper to modify the lithium-rich manganese-based oxide (LRMO, Li1.2Mn0.54Ni0.13Co0.13O2) to improve its electrochemical properties. Zirconium-based compounds coated LRMO materials (ZBC@LRMO) were obtained via the reaction of lithium hydroxide with zirconium n-butanol and subsequent thermal treatment at different temperatures. The results of X-ray diffraction and transmission electron microscopy confirm that the crystal structure and composition of the ZBC coating layer vary with the calcination temperature. The coating layer obtained at 600 ℃ is composed of tetragonal ZrO2 and Li2ZrO3. The ZBC@LRMO sample with tetragonal ZrO2 and Li2ZrO3 composite exhibits the best electrochemical performance: the discharge capacity of ZBC@LRMO can reach 296 mAh g-1 at 0.1 C and 120 mAh g-1 at high rate of 5 C. 相似文献
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Limin SHEN Jianming GONG Yong JIANG Luyang GENG College of Mechanical Power Engineering Nanjing University of Technology Nanjing China 《金属学报(英文版)》2011,(3):235-242
Cr25Ni35Nb and Cr35Ni45Nb alloys are usually used in the ethylene cracking furnaces.However,premature failure of furnace tubes often occurs ahead of design life due to elevated temperature exposure conditions (1050-1100 ℃) and aggressive service environment.Effects of exposure temperature and time on microstructure and mechanical properties of Cr25Ni35Nb and Cr35Ni45Nb steel at aging temperature (1200 ℃) with various exposure time were simulated different service times at 1050 ℃.Change of mechanical propert... 相似文献