摘要
通过形变退火再结晶的方式制备了晶粒尺寸在100~200μm的铈样品,并研究了这些样品在50~200℃,初始压力为5 kPa氢气下的氢化点长大规律。结果表明,金属铈的氢化点长大速率随着反应温度的升高而增大,晶粒尺寸为100~200μm之间的铈样品在200℃的氢化点长大速率是其在50℃下的9.5~7.4倍,且氢化点长大速率与反应温度之间符合阿伦尼乌斯关系,其反应的激活能在0.18~0.21 eV。随着铈样品晶粒尺寸的减小,氢化点长大的速率加快。对氢化后样品的微观组织分析发现,晶界有利于铈样品的氢化点成核与氢的扩散,从而导致宏观上细晶样品的氢化点长大增快。由于晶粒尺寸的变化并未改变氢在铈中的扩散机制,因此晶粒尺寸变化并未改变铈的氢化点长大过程中的激活能。
Cerium samples with grain sizes of 100-200μm were prepared by deformation annealing and recrystallization.The growth of hydride points of these samples at the initial pressure of 5 kPa hydrogen at 50-200℃was studied.The results show that the growth velocity of hydride point increases with increase of reaction temperature.The hydride points growth rate of cerium samples with grain size of 100-200μm at 200°C is 9.5 to 7.4 times faster than that at 50°C,and the hydride point growth velocity is in accordance with the Arrhenius relationship vs the reaction temperature.The activation energy of the reaction is in range of 0.18-0.21 eV.As the grain size of cerium samples decreases,the growth velocity of hydride points increases.The microstructure analysis of the samples after hydrogenation showsthat the grain boundary is conducive to the hydride point nucleation and hydrogen diffusion in the cerium sample,which leads to the rapid growth of the hydrogenation point of the fine crystalline cerium samples.The change of grain size has no influence on the activation energy of the hydride points growth because the diffusion mechanism remainsthe same.
作者
黄宇
王维
叶小球
张新建
Huang Yu;Wang Wei;Ye Xiaoqiu;Zhang Xinjian(Institute of Materials,China Academy of Engineering Physics,Mianyang 621907,China;China Aerospace Technology Co.Ltd.,Chengdu 610501,China;Science and Technology on Surface Physics and Chemistry Laboratory,Mianyang 621908,China)
出处
《中国稀土学报》
北大核心
2025年第4期863-870,共8页
Journal of the Chinese Society of Rare Earths
基金
国家自然科学基金项目(22272154)
表面物理与化学重点实验室基金(TCGH070406,JBNY0601)资助。
关键词
铈
晶粒尺寸
氢化
氢化点长大速率
激活能
cerium
grain size
hydrogenate
hydride point growth velocity
activation energy
