论文标题
CO7MO6 MU期热膨胀路径的第一原理计算
First-principles calculations of thermal expansion path of the Co7Mo6 Mu-phase
论文作者
论文摘要
MU期是一种金属间化合物，可以在钢和超合金中形成，并显着降低其机械性能。基于第一原理的准谐波Debye-Grüneisen近似以及通过比较沿不同热膨胀路径计算的自由能，已经研究了CO7MO6 MU期的热膨胀。对从0 K到1500 K的温度进行计算，该温度低于CO7MO6的分解温度。考虑了对自由能的电子，振动和磁能的贡献。 CO7MO6的热膨胀不是各向同性的。分析了物理因素对CO7MO6稳定性的影响。报道了等同的热容量，热膨胀，弹性常数，大量模量，声波速度，Debye和Curie温度。分析了计算结果，并与可用的实验和理论数据一致。
The Mu-phase, which is an intermetallic compound, can form in steels and superalloys, and significantly degrade their mechanical properties. The thermal expansion of Co7Mo6 Mu-phase have been investigated by first-principles based quasi-harmonic Debye-Grüneisen approximation and by comparing the free energies calculated along different paths of thermal expansion. The calculations were carried out for temperatures from 0 K to 1500 K which below the decomposition temperature of Co7Mo6. The electronic, vibrational and magnetic energy contributions to the free energy were accounted. The thermal expansion of Co7Mo6 is not isotropic. The influence of physical factors on the stability of Co7Mo6 was analyzed. The isobaric heat capacity, thermal expansion, elastic constants, bulk modulus, sound wave velocities, Debye and Curie temperatures were reported. The calculated results analyzed and are in an agreement with the available experimental and theoretical data.
