https://hdl.handle.net/11256/924 Datasets submitted in support of articles published as JPED may be archived at the NIST data repository. 2026-04-08T09:54:25Z https://hdl.handle.net/11256/944 Interdiffusion in the Ni-Re System: Evaluation of Uncertainties Boettinger, William J; Williams, Maureen E; Moon, Kil-Won; McFadden, Geoffrey B; Patrone, Paul N; Perepezko, John H Diffusion couple experiments between Ni and Re at 1200 and 1350 °C were performed. These experiments established the limits of the two-phase FCC + HCP region. No intermediate phase was observed at these temperatures. Composition-dependent interdiffusion coefficients and associated uncertainties were estimated by three methods. The first employed fitting of the penetration curves in conjunction with the Sauer-Freise (SF) method. The second method employed a numerical solution of the Boltzmann-Matano ordinary differential equation for composition-dependent interdiffusion coefficient functions whose parameters were optimized by a least squares fitting to the data. Discrepancies between the results of these methods indicate typical uncertainties in experimental determination of diffusion coefficients. To further assess such discrepancies, a third method was employed to pe form an uncertainty quantification of the diffusion coefficients via a statistical analysis based on the SF method. 2017-06-22T00:00:00Z https://hdl.handle.net/11256/943 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 https://hdl.handle.net/11256/935 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 https://hdl.handle.net/11256/718 Thermodynamic assessment of the Co-Mo system A. Davydov; U. R. Kattner Experimental thermochemical and phase diagram data for the Co-Mo system were assessed. A consistent thermodynamic description, using a Redlich-Kister model for the solution phases and sublattice and line-compound models for the intermetallics, was obtained, and it agreed well with the critically evaluated experimental data. Several variations of the sublattice model for the and phases were compared with the traditional models used for these phases in other systems. Measured data indicate an abrupt decrease of the terminal Mo solubility in the fcc (Co) phase with decreasing temperature. This behavior was reproduced well by inclusion of the magnetic contribution to the Gibbs energy of the fcc phase. Addition of the magnetic term also led to the prediction of a fcc (Co) miscibility gap, and a high-temperature stability region of the paramagnetic cph (Co) phase.