Stability, electronic structures, and mechanical properties of Fe–Mn–Al system from first-principles

• 作 者: 刘亚会 种晓宇 蒋业华 冯晶
• 机 构: Faculty of Materials Science and Engineering, Kunming University of Science and Technology,
• 出 处: Chinese Physics B
• 发表日期: 2017年03期
• 关键词: modulus enthalpy bonding covalent anisotropic metallic Mn Stability constants an

The stability, electronic structures, and mechanical properties of the Fe–Mn–Al system were determined by firstprinciples calculations. The formation enthalpy and cohesive energy of these Fe–Mn–Al alloys are negative and show that the alloys are thermodynamically stable. Fe_3Al, with the lowest formation enthalpy, is the most stable compound in the Fe–Mn–Al system. The partial density of states, total density of states, and electron density distribution maps of the Fe–Mn–Al alloys were analyzed. The bonding characteristics of these Fe–Mn–Al alloys are mainly combinations of covalent bonding and metallic bonds. The stress-strain method and Voigt–Reuss–Hill approximation were used to calculate the elastic constants and moduli, respectively. Fe_(2.5)Mn_(0.5)Al has the highest bulk modulus, 234.5 GPa. Fe_(1.5)Mn_(1.5)Al has the highest shear modulus and Young’s modulus, with values of 98.8 GPa and 259.2 GPa, respectively. These Fe–Mn–Al alloys display disparate anisotropies due to the calculated different shape of the three-dimensional curved surface of the Young’s modulus and anisotropic index. Moreover, the anisotropic sound velocities and Debye temperatures of these Fe–Mn–Al alloys were explored.

The stability, electronic structures, and mechanical properties of the Fe-Mn-Al system were determined by firstprinciples calculations. The formation enthalpy and cohesive energy of these Fe-Mn-Al alloys are negative and show that the alloys are thermodynamically stable. Fe_3Al, with the lowest formation enthalpy, is the most stable compound in the Fe-Mn-Al system. The partial density of states, total density of states, and electron density distribution maps of the Fe-Mn-Al alloys were analyzed. The bonding characteristics of these Fe-Mn-Al alloys are mainly combinations of covalent bonding and metallic bonds. The stress-strain method and Voigt-Reuss-Hill approximation were used to calculate the elastic constants and moduli, respectively. Fe_ (2.5) Mn_ Al has the highest bulk modulus, 234.5 GPa. Fe 1.5 Mn 1.5 Al has the highest shear modulus and Young’s modulus, with values ​​of 98.8 GPa and 259.2 GPa, respectively. These Fe-Mn-Al alloys display disparate anisotropies due to the calculated different shape of the three-dimensional curved surface of the Young’s modulus and anisotropic index. Moreover, the anisotropic sound velocities and Debye temperatures of these Fe-Mn-Al alloys were explored.