A computational high-throughput search for new ternary superalloys. (1st January 2017)

• Record Type: Journal Article
• Authors: Nyshadham, Chandramouli; Oses, Corey; Hansen, Jacob E.; Takeuchi, Ichiro; Curtarolo, Stefano; Hart, Gus L.W.
• Is Part Of: Acta materialia. Volume 122(2017)
• Page Start: 438
• Page End: 447
• Publication Date: 2017-01-01
• Subjects: First-principles calculations -- Superalloys -- High-throughput -- Phase stability; Materials -- Periodicals; Materials science -- Periodicals; Materials -- Mechanical properties -- Periodicals; Metallurgy -- Periodicals; Chemistry, Inorganic -- Periodicals; 620.112
• DOI: 10.1016/j.actamat.2016.09.017
• Languages: English
• ISSNs: 1359-6454

Abstract

Abstract: 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 X 3 [ A 0.5, B 0.5 ], 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 ( X 3 [ A x, B 1− 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. Graphical abstract: