Phase Equilibria Data to supplement publications in JPED https://hdl.handle.net/11256/926 2021-09-14T12:15:29Z 2021-09-14T12:15:29Z Ilatovskaia, Mariia Savinykh, Galina Fabrichnaya, Olga https://hdl.handle.net/11256/943 2017-06-13T14:34:38Z 2017-06-08T00:00:00Z

Thermodynamic Description of the Ti-Al-O System Based on Experimental Data Ilatovskaia, Mariia; Savinykh, Galina; Fabrichnaya, Olga Phase equilibria of the TiO2-Al2O3 system were investigated experimentally using XRD, SEM/EDX and DTA methods. Temperature stability limits of the aluminum titanate (Al2TiO5) were detected. The thermodynamic parameters of the liquid phase as well as solid solution phases were assessed by CALPHAD approach using obtained experimental results. The thermodynamic data for the Ti-Al, Al-O and Ti-O systems and available experimental data for the Ti-Al-O system were critically evaluated and optimized to develop database of the Ti-Al-O system.

2017-06-08T00:00:00Z Zhu, Jun Titus, Michael S Pollock, Tresa M https://hdl.handle.net/11256/935 2017-03-21T03:04:45Z 2017-03-20T00:00:00Z

Experimental Investigation and Thermodynamic Modeling of the Co-Rich Region in the Co-Al-Ni-W Quaternary System Zhu, Jun; Titus, Michael S; Pollock, Tresa M The stabilities of the γ-(Co), γ′-Co3(Al,W), μ-Co7W6, β-CoAl and α-(W) phases in the Co-Al-W and Ni-Al-W ternary systems were investigated at 900, 1000, 1100 and 1300 °C. Electron probe microanalysis was used to determine compositions of the phases. Scanning electron microscopy was used to determine area fractions of the phases present after heat treatments. Thermodynamic modeling of the Co-Al-Ni-W quaternary system, using Pandat software, was incorporated to determine relevant thermodynamic parameters for phases in the Co-rich region of the system. Phases were modeled using the substitutional solution model and compound energy formalism. Excellent agreement was found between experiments and thermodynamic modeling. This new thermodynamic database enables predictions of stable γ-γ′ compositions for a new class of high temperature, high strength Co-base superalloys.

2017-03-20T00:00:00Z Lass, Eric Maureen E. Williams Carelyn E. Campbell Kil-Won Moon Ursula R. Kattner https://hdl.handle.net/11256/96 2017-02-02T03:42:40Z 2014-09-03T00:00:00Z

Al-Co-W 900C Phase Equilibria Data Lass, Eric; Maureen E. Williams; Carelyn E. Campbell; Kil-Won Moon; Ursula R. Kattner Phase equilibria at 900 °C in the Co-rich Co-Al-W ternary system are investigated through isothermal annealing of six alloy compositions for times up to 8000 h. The volume fraction of the L12-γ′ phase co-existing with disordered FCC-γ, B2 and D019 phases is found to steadily decrease with increasing annealing time indicating that it is unstable at 900 °C. Additional heat treatments at 850 and 1000 °C further suggest it is a nonequilibrium phase at all temperatures in the ternary system. The L12-γ′ phase dissolves slowly with significant amounts remaining in some alloys after 8000 h at 900 °C. However, the present work clearly indicates the microstructure is moving toward a three-phase equilibrium between γ, D019, and B2. The collected compositional and phase equilibria information provide much needed data for improving the available thermodynamic assessments of the ternary Co-Al-W alloy system.

2014-09-03T00:00:00Z