磁场下碳化物析出的热力学机制  

Thermodynamic mechanism of carbide precipitation under magnetic field

作　　者：廖已莹 侯廷平[1,2,3] 杨雨豪 郑一航 于涛 刘伍明[5] 吴开明[1,2,3] LIAO Yi-Ying;HOU Ting-Ping;YANG Yu-Hao;ZHENG Yi-Hang;YU Tao;LIU Wu-Ming;WU Kai-Ming(College of Science,Wuhan University of Science and Technology,Wuhan 430081,China;Hubei Province Key Laboratory of Systems Science in Metallurgical Process,Wuhan 430081,China;State Key Laboratory of Refractories and Metallurgy,Wuhan 430081,China;Key Laboratory of Optoelectronic Chemical Materials and Devices of Ministry of Education,School of Optoelectronic Materials and Technology,Jianghan University,Wuhan 430056,China;Institute of Physics Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]武汉科技大学理学院,武汉430081 [2]冶金工业过程系统科学湖北省重点实验室,武汉430081 [3]省部共建耐火材料与冶金国家重点实验室,武汉430081 [4]江汉大学光电材料与技术学院光电化学材料与器件教育部重点实验室,武汉430056 [5]中国科学院物理研究所,北京100190

出　　处：《原子与分子物理学报》2025年第4期121-130,共10页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(12174296,61835013,12174461,12234012,12334012);国家重点研发计划(2021YFA1400900,2021YFA0718300,2021YFA1400243);湖北省自然科学基金一般面上项目(2022CFB474);2021年度省级大学生创新创业训练计划项目(S202110488049);江汉大学校级科研项目(2021yb026)。

摘　　要：钢中碳化物的形成主要由合金元素的种类以及含量的决定,碳化物对钢铁材料的显微组织形态和力学性能有重要影响.磁场是影响碳化物析出规律发生改变的重要因素之一.以常见的碳化物M_(6)C(M=Fe,Mo)作为研究对象,利用第一性原理计算η-Fe_(2)C、Fe_(3)C、Fe_(2)Mo_(4)C、Fe_(3)Mo_(3)C-Ⅰ、Fe_(3)Mo_(3)C-Ⅱ和Fe_(4)Mo_(2)C等合金碳化物的磁矩,计算结果表明其中Fe_(4)Mo_(2)C的磁矩最大,达到了7.04μB.磁矩不仅由碳化物晶胞中Fe原子个数有关,还与Fe Wyckoff占位紧密相关.通过模拟计算碳化物的磁致磁热熔、磁熵、磁焓和磁自由能,从热力学角度对各碳化物进行分析,结果表明磁场会使碳化物的磁致磁热熔和磁熵增加;强磁场会降低M_(6)C的磁自由能进而提高其稳定性.此工作为研究核聚变材料磁性能提供理论基础和技术参考.The formation of carbides in steel is determined by the type and quantity of alloying elements.Carbides will affect the microstructure and mechanical properties of steel materials.The magnetic field is an important factor affecting the precipitation of carbides.In this paper,the common precipitated phase M_(6)C(M=Fe,Mo)carbides are selected as the research object.The magnetic moments of η-Fe_(2)C,Fe_(3)C,Fe_(2)Mo_(4)C,Fe_(3)Mo_(3)C-Ⅰ,Fe_(3)Mo_(3)C-Ⅱ and Fe_(4)Mo_(2)C are calculated by first-principles.The magnetic moment of Fe_(4)Mo_(2)C is the largest with the value of 7.04μB.The magnetic moment is not only related to the number of Fe atoms in carbides,but also closely related to the crystallographic occupation of Fe atoms.By simulating the magnetic heat capacity,magnetic entropy,magnetic enthalpy and magnetic free energy of carbides,the carbides were analyzed from the thermodynamic point of view.The results show that the magnetic field will increase the magnetic heat capacity and magnetic entropy of carbides.The strong magnetic field will increase the magnetic free energy of M_(6)C and improve its stability.This work provides a theoretical basis and technical reference for studying the magnetic properties of nuclear fusion materials.

关 键 词：磁场 碳化物 析出相 热力学机制 

分 类 号：O56[理学—原子与分子物理]