Elastic and thermodynamic properties of zirconium- and hafnium-doped Rh$_3$V intermetallic compounds: potential aerospace material

Bulletin of Materials Science

关键词: Electronic band structure;    elastic properties;    mechanical properties;    ductility;    Debye temperature.;   

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

Structural, electronic, mechanical and thermodynamic properties of Rh$_3$Zr$_x$V$_{1−x}$ and Rh$_3$Hf$_x$V$_{1−x} ($x = 0$, 0.125, 0.25, 0.75, 0.875 and 1) combinations are investigated by means of first-principles calculations based on the density functional theory within the generalized gradient approximation. Here, Rh$_3$V is chosen as the parent binary compound and the doping elements are zirconium and hafnium with the above-mentioned concentrations. The calculated lattice parameters and elastic modulus of binary Rh$_3$Hf, Rh$_3$V and Rh$_3$Zr are in good agreement with the available experimental and other theoretical results. In this study, the following ternary materials viz., Rh$_3$Zr$_{0.75}$V$_{0.25}$, Rh$_3$Hf$_{0.25}$V$_{0.75}$ and Rh$_3$Hf$_{0.75}$V$_{0.25}$ are found to be brittle/more brittle than the parent binary compound Rh$_3$V, whereas the other ternary combinations, namelyRh$_3$Zr$_{0.125}$V$_{0.875}$, Rh$_3$Zr$_{0.25}$V$_{0.75}$, Rh$_3$Zr$_{0.875}$V$_{0.125}$, Rh$_{3}Hf$_{0.125}$V$_{0.875}$ and Rh$_3$Hf$_{0.875}$V$_{0.125}$ are found to be more ductilethanRh3V. The more brittle ternary combination, namely Rh$_3$Hf$_{0.75}$V$_{0.25}$ ($B = 229.32$ GPa) has the maximum Young’s modulus,shear modulus and hardness values; whereas the more ductile ternary Rh$_3$Zr$_{0.25}$V$_{0.75}$ combination ($B = 243.54$ GPa) is found to have the least values of Young’s modulus, shear modulus and hardness. The band structure, density of stateshistograms and charge density plots are drawn and discussed. Computed Debye temperature (θD), Grüneisen parameter ($\zeta$) and melting temperature ($T_{\rm m}$) of the parent binary compound Rh$_3$V, the more brittle Rh$_3$Hf$_{0.75}V$_{0.25}$ combination and themore ductile Rh$_3$Zr$_{0.25}$V$_{0.75}$ combination are given by (895 K, 1.3491, 2788 K), (790 K, 1.2701, 2736K) and (698 K, 1.7972, 2529 K), respectively.

【 授权许可】

CC BY