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Title: Experimental study and thermodynamic modeling of the Al–Co–Cr–Ni system

In this study, a thermodynamic database for the Al–Co–Cr–Ni system is built via the Calphad method by extrapolating re-assessed ternary subsystems. A minimum number of quaternary parameters are included, which are optimized using experimental phase equilibrium data obtained by electron probe micro-analysis and x-ray diffraction analysis of NiCoCrAlY alloys spanning a wide compositional range, after annealing at 900 °C, 1100 °C and 1200 °C, and water quenching. These temperatures are relevant to oxidation and corrosion resistant MCrAlY coatings, where M corresponds to some combination of nickel and cobalt. Comparisons of calculated and measured phase compositions show excellent agreement for the β–γ equilibrium, and good agreement for three-phase β–γ–σ and β–γ–α equilibria. An extensive comparison with existing Ni-base databases (TCNI6, TTNI8, NIST) is presented in terms of phase compositions.
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  1. Univ. of Pittsburgh, Pittsburgh, PA (United States)
  2. The Pennsylvania State Univ., University Park, PA (United States)
Publication Date:
OSTI Identifier:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Science and Technology of Advanced Materials
Additional Journal Information:
Journal Volume: 16; Journal Issue: 5; Journal ID: ISSN 1468-6996
IOP Publishing
Research Org:
Univ. of Pittsburgh, Pittsburgh, PA (United States)
Sponsoring Org:
Country of Publication:
United States
36 MATERIALS SCIENCE; bondcoat; phase compositions; phase equilibrium; Calphad; MCrAlY