...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Surface & Coatings Technology >Isothermal oxidation kinetics of nanocrystalline and coarse grained nickel: Experimental results and theoretical approach
【24h】

Isothermal oxidation kinetics of nanocrystalline and coarse grained nickel: Experimental results and theoretical approach

机译：纳米晶和粗晶镍的等温氧化动力学：实验结果和理论方法

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

In this research, isothermal oxidation kinetics of nanocrystalline (NC) nickel prepared by electroplating as well as coarse grained (CG) nickel was investigated. Oxidation tests were carried out in static air for various durations at 700°C, 800°C and 900°C. The structure of oxidized specimens was characterized by means of SEM and XRD. Moreover, a theoretical model based on Atkinson approach as well as Maxwell Equation was proposed. The derived model was checked by fitting the theoretical curves to the experimental data using Matlab software. Good agreement between theoretical model and obtained experimental results as well as reported data was observed. The results indicated that the weight gain per unit area (w=Δm/A) of NC samples was considerably higher than the CG nickel. Moreover, the decrease in the parabolic growth rate constant (k_p) of NC nickel by increasing the oxidation time was sharper than the microcrystalline samples. In spite of the overall data of log (k_p), the logarithms of k_p values corresponding to a given w was a linear function of the reciprocal temperature resulted an activation energy of ~108kJ/mol for oxide layer growth on NC nickel as well as CG samples. In addition, the values for the activation energy for grain boundary diffusion of Ni in NiO layer which are determined from the fitting parameters for NC and CG nickel, both were close to that for the growth of NiO layer.
机译：在这项研究中，研究了通过电镀制备的纳米晶（NC）镍以及粗晶（CG）镍的等温氧化动力学。在静态空气中分别在700°C，800°C和900°C下进行氧化测试。氧化样品的结构通过SEM和XRD表征。提出了基于阿特金森方法和麦克斯韦方程的理论模型。通过使用Matlab软件将理论曲线拟合到实验数据来检查导出的模型。观察到理论模型与获得的实验结果以及报道的数据之间的良好一致性。结果表明，NC样品的单位面积重量增加（w =Δm/ A）大大高于CG镍。此外，通过增加氧化时间，NC镍的抛物线生长速率常数（k_p）的降低比微晶样品更明显。尽管有log（k_p）的整体数据，但与给定w对应的k_p值的对数是倒数温度的线性函数，导致NC镍和CG上氧化物层生长的活化能为〜108kJ / mol样品。此外，由NC和CG镍的拟合参数确定的NiO层中Ni的晶界扩散活化能的值均接近于NiO层的生长。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号