title: First-principles calculations, experimental study, and thermodynamic modeling of the Al-Co-Cr system.
abstract: The phase relations and thermodynamic properties of the condensed Al-Co-Cr ternary alloy system are investigated using first-principles calculations based on density functional theory (DFT) and phase-equilibria experiments that led to X-ray diffraction (XRD) and electron probe micro-analysis (EPMA) measurements. A thermodynamic description is developed by means of the calculations of phase diagrams (CALPHAD) method using experimental and computational data from the present work and the literature. Emphasis is placed on modeling the bcc-A2, B2, fcc-γ, and tetragonal-σ phases in the temperature range of 1173 to 1623 K. Liquid, bcc-A2 and fcc-γ phases are modeled using substitutional solution descriptions. First-principles special quasirandom structures (SQS) calculations predict a large bcc-A2 (disordered)/B2 (ordered) miscibility gap, in agreement with experiments. A partitioning model is then used for the A2/B2 phase to effectively describe the order-disorder transitions. The critically assessed thermodynamic description describes all phase equilibria data well. A2/B2 transitions are also shown to agree well with previous experimental findings.
authors: Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania, 16802, United States of America.
authors: Xuan L
authors: XL
authors: Liu
authors: Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania, 15261, United States of America.
authors: Thomas
authors: T
authors: Gheno
authors: Department of Materials Science and Engineering, KTH Royal Institute of Technology, SE-100 44, Stockholm, Sweden.
authors: Bonnie B
authors: BB
authors: Lindahl
authors: Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania, 16802, United States of America.
authors: Greta
authors: G
authors: Lindwall
authors: Department of Mechanical Engineering and Materials Science, University of Pittsburgh, Pittsburgh, Pennsylvania, 15261, United States of America.
authors: Brian
authors: B
authors: Gleeson
authors: Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania, 16802, United States of America.
authors: Zi-Kui
authors: ZK
authors: Liu
mesh_terms: D000497:Alloys / Q000737:chemistry*; D000535:Aluminum / Q000737:chemistry*; D002857:Chromium / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry*; D008956:Models, Chemical; D044367:Phase Transition; D013816:Thermodynamics; D014961:X-Ray Diffraction
chemical_list: D000497:Alloys; D002857:Chromium; D003035:Cobalt; D000535:Aluminum