Effect of valence electron concentration on stability of fcc or bcc phase in high entropy alloys

Abstract

Hydrogen quantum effects in hydride LaNi5H7J. Appl. Phys. 110, 063533 (2011) Accurate determination of the Gibbs energy of Cu-Zr melts using the thermodynamic integration method in Monte Carlo simulations J. Chem. Phys. 135, 084502 (2011) Efficient calculation of -and -nitrogen free energies and coexistence conditions via overlap sampling with targeted perturbation J. Chem. Phys. 135, 044125 (2011) An incremental mean first passage analysis for a quasistatic model of polymer translocation through a nanopore J. Chem. Phys. 134, 154905 (2011) The effect of pressure on the phase transition behavior of tridecane, pentadecane, and heptadecane: A Fourier transform infrared spectroscopy study J. Chem. Phys. 134, 144503 (2011) Additional information on J. Appl. Phys. Phase stability is an important topic for high entropy alloys (HEAs), but the understanding to it is very limited. The capability to predict phase stability from fundamental properties of constituent elements would benefit the alloy design greatly. The relationship between phase stability and physicochemical/thermodynamic properties of alloying components in HEAs was studied systematically. The mixing enthalpy is found to be the key factor controlling the formation of solid solutions or compounds. The stability of fcc and bcc solid solutions is well delineated by the valance electron concentration (VEC). The revealing of the effect of the VEC on the phase stability is vitally important for alloy design and for controlling the mechanical behavior of HEAs.

Hybrid Monte Carlo/Molecular Dynamics Simulation of a Refractory Metal High Entropy Alloy

“…Atomic size drops as group number increases, and to a lesser as row number increases. Hence, we understand the sequence of atomic volumes (in units ofÅ 3 [11,12]. In this paper we will mainly refer to atomic size, but in fact both (9) cI2 (0) size and electronegativity play mutually reinforcing roles.…”

“…If every lattice site were to be occupied with equal probability by each of the four elements, a configurational entropy of k B ln 4 ∼ 1.2 × 10 −4 eV/K would result. However, atomic size, enthalpy of mixing and additional considerations surely affect stability also [3][4][5][6][7]. Indeed, decomposition into multiple phases has been observed experimentally in certain high entropy alloy families [8][9][10].…”

High-Entropy Alloys: A Critical Review

“…Notes: Fully closed symbols for sole FCC phases; fully open symbols for sole BCC phase; top-half closed symbols for mixed FCC and BCC phases. [38] weighted average VEC of the constituent components). Guo et al summarized the relationship between VEC and structure of many HEAs ( Figure 5).…”

A Novel Low-Density, High-Hardness, High-entropy Alloy with Close-packed Single-phase Nanocrystalline Structures

“…One descriptor that has been reasonably successful in predicting the lattice structure is the average valence concentration (or average periodic table group number) (VEC). [5] Fcc phases were determined to be more stable at higher values of VEC ( ≥ 8) while bcc phases were stable at lower VEC ( < 6.87). On the boundary between fcc and bcc (VEC = 8), the systems were found to be predominantly fcc but in some situations the bcc phase has been seen in minute amounts.…”