A computational high-throughput search for new ternary superalloys

Published

Journal Article

© 2016 Acta Materialia Inc. In 2006, a novel cobalt-based superalloy was discovered [1] with mechanical properties better than some conventional nickel-based superalloys. As with conventional superalloys, its high performance arises from the precipitate-hardening effect of a coherent L12 phase, which is in two-phase equilibrium with the fcc matrix. Inspired by this unexpected discovery of an L12 ternary phase, we performed a first-principles search through 2224 ternary metallic systems for analogous precipitate-hardening phases of the form X3[A0.5,B0.5], where X = Ni, Co, or Fe, and [A,B] = Li, Be, Mg, Al, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn Ga, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, or Tl. We found 102 systems that have a smaller decomposition energy and a lower formation enthalpy than the Co3(Al, W) superalloy. They have a stable two-phase equilibrium with the host matrix within the concentration range 0 < x < 1 (X3[Ax,B1−x]) and have a relative lattice mismatch with the host matrix of less than or equal to 5%. These new candidates, narrowed from 2224 systems, suggest possible experimental exploration for identifying new superalloys. Of these 102 systems, 37 are new; they have no reported phase diagrams in standard databases. Based on cost, experimental difficulty, and toxicity, we limit these 37 to a shorter list of six promising candidates of immediate interest. Our calculations are consistent with current experimental literature where data exists.

Full Text

Duke Authors

Cited Authors

  • Nyshadham, C; Oses, C; Hansen, JE; Takeuchi, I; Curtarolo, S; Hart, GLW

Published Date

  • January 1, 2017

Published In

Volume / Issue

  • 122 /

Start / End Page

  • 438 - 447

International Standard Serial Number (ISSN)

  • 1359-6454

Digital Object Identifier (DOI)

  • 10.1016/j.actamat.2016.09.017

Citation Source

  • Scopus