The comparison of different approaches to the modeling of the structural properties σ-phase of Fe-Cr system

10th International School-Conference on Materials for Extreme Environment: Development, Production and Application

Udovsky, A.L.^1,2 ; Kupavtsev, M.V.^1

Federal State Budgetary Organization, Science Baikov Institute of Metallurgy and Materials Science, Russian Academy of Sciences, Russia^1

National Research Nuclear University MEPhI, Moscow Engineering Institute, Russia^2

关键词: Ab initio calculations;    Alloys composition;    Atom distribution;    Coordination number;    Energetic parameters;    Fitting procedure;    Paramagnetic state;    Temperature dependence;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/130/1/012064/pdf
DOI  :  10.1088/1757-899X/130/1/012064

来源: IOP

【 摘 要 】

The three- sub-lattice model (3SLM) for description of atom's distribution of two components with different coordination numbers (12, 14 and 15), into σ-phase structure depended on composition and temperature is depictured in this paper. Energetic parameters of 3SLM were calculated by fitting procedure fixed to results obtained by ab-initio calculations conducted for paramagnetic states of differently ordered complexes stayed at the sigma- phase's crystal structure for Fe-Cr system at 0 K. Respective algorithm and computer program have allowed to calculate an atom distribution of components upon the sub-lattices of σ-phase at 300 - 1100 K. The temperature dependences of filling atoms on the model three sub-lattices for alloys compositions 40, 50 and 60 at. % Fe was calculated. There is satisfactory agreement between calculated results and the experimental data obtained by neutron and structural research methods. The equilibrium between BCC solutions and σ- phase of Fe-Cr system was calculated. The satisfactory consent of results of calculation with experimental data for education temperature σ- phases from BCC- solution and some divergences with experiments is received at 800 K.