[1]罗群,周国治,陈双林,等.基于热力学和动力学计算的Mg-Ni-RE(La,Nd,Ce,Y)-H多元系设计及应用[J].中国材料进展,2016,(01):036-40.[doi:10.7502/j.issn.1674-3962.2016.01.07]
 LUO Qun,CHOU Kuochih,CHEN Shuanglin,et al.Material Design of Mg-Ni-RE (La,Nd,Ce,Y)-H System Based on Thermodynamics and Kinetics Calculation[J].MATERIALS CHINA,2016,(01):036-40.[doi:10.7502/j.issn.1674-3962.2016.01.07]
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基于热力学和动力学计算的Mg-Ni-RE(La,Nd,Ce,Y)-H多元系设计及应用()
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中国材料进展[ISSN:1674-3962/CN:61-1473/TG]

卷:
期数:
2016年第01期
页码:
036-40
栏目:
特约研究论文
出版日期:
2016-01-30

文章信息/Info

Title:
Material Design of Mg-Ni-RE (La,Nd,Ce,Y)-H System Based on Thermodynamics and Kinetics Calculation
作者:
 罗群1周国治1陈双林1李谦1 2 张捷宇 1
 (1. 上海大学,省部共建高品质特殊钢冶金与制备国家重点实验室
(2. 上海大学,材料基因组工程研究院
Author(s):
LUO Qun 1 CHOU Kuochih 1 CHEN Shuanglin 1 LI Qian 1 2 ZHANG Jieyue 1
 (1. State Key Laboratory of Advanced Special Steels, Shanghai University
(2. Institute of Genomic Material, Shanghai University
关键词:
稀土-镁基合金Mg-Ni-RE (LaNdCeY)-H热力学动力学材料设计
DOI:
10.7502/j.issn.1674-3962.2016.01.07
文献标志码:
A
摘要:
稀土因性质活泼被以单质或者中间合金的方式添加到镁基储氢合金中形成稀土-镁基体系储氢合金,该合金由于具有优良的储氢性能而备受关注。但是目前缺少多元系稀土-镁基合金相图的指导,难免在设计材料配方时出现盲区,继而陷入“炒菜”式的摸索之中,缺乏针对性。储氢材料的吸放氢反应动力学研究,目前绝大多数的实验反复测定恒温条件下的反应分数与时间的关系上,很少研究各种因数,诸如温度、气相分压、颗粒大小等对反应速率的影响,更谈不上颗粒分布、变温变速等对反应速率的影响。基于热力学和动力学计算,研究了Mg-Ni-RE(La, Nd, Ce, Y)-H多元系,通过引入氢组元对比说明清楚相关储氢合金与金属氢化物的热力学稳定性的差别,利用CALPHAD技术预报多元系的压力-组成-温度(PCT)曲线,结合原位高温XRD和高分辨透射电镜(HR-TEM)结果,阐释了储氢合金吸放氢的热力学机制。同时,通过研究恒温和变温条件下氢化还原反应动力学模型,将吸放氢反应分数表达为温度、压力、颗粒大小、颗粒形貌等因素的函数,不但简化了计算,而且还便于从理论上对各种物理量进行讨论。引进了一个“特征时间”的新概念,它将在储氢材料的研究中发挥重要的作用。
Abstract:
Rare earth (RE) elements have been added into Mg-based hydrogen storage alloys to form Mg-based RE-Mg hydrogen storage alloys due to their active properties. These alloys have attracted extensive attention owning to their good hydrogen storage performance. However, because of the lack of the guidance by phase diagrams in the RE-Mg system, the material design is aimlessly and would fall into a “cooking” exploration. For the study of hydriding and dehydriding kinetics, the current experimental measurement mainly repeated on determining the relationship between reaction fraction and time at isothermal condition. Few research focused on the effect of temperature, pressure, particle size… on the reaction rate, much less the particle size distribution, heating rate and other factors. This work investigates the Mg-Ni-RE(La,Nd,Ce,Y)-H quarternary system based on the thermodynamic and kinetic calculations. The calculation based on thermodynamic database reveals the thermodynamic stability of hydrogen storage alloys and hydrides. The Pressure-Composition-Temperature (PCT) curves are predicted through CALPHAD method. The thermodynamic calculation and experimental results of in situ X-ray diffraction (XRD) and high resolution transmission electron microscopy (HR-TEM) indicate the thermodynamic mechanism of hydriding and dehydriding. Meanwhile, the isothermal and non-isothermal hydriding/dehydriding kinetics are investigated and the reacted fraction is expressed as a function of temperature, pressure, particle size, particle morphology etc. This method not only simplifies the calculation, but also makes the physical quantities easy to discuss theoretically. A new concept “characteristic time” is introduced, which will act an important role in the research of hydrogen storage materials.
更新日期/Last Update: 2016-01-28