Papers by Keyword: Phase Equilibria

Paper TitlePage

Authors: Kazutaka Sasaki, Ludwig J. Gauckler
Authors: M. Kurzawa, I. Rychlowska-Himmel, M. Bosacka, G. Dabrowska
Authors: S.M. Bokoch, Valentin A. Tatarenko
Abstract: Using both the statistical-thermodynamics methods within the scope of the selfconsistent field approximation and the diffraction data on coherent (or diffuse) scattering of X-rays (or thermal neutrons) from (dis)ordered f.c.c.-Ni–Fe alloys of various compositions, the estimation of interatomic interactions (including their magnetic contribution) and their temperature– concentration dependences were obtained. Based on the static concentration-wave representation, the expressions for configuration free energies of L12-Ni3Fe-type permalloy, L10-NiFe-type elinvar and L12-Fe3Ni-type invar were analyzed, considering explicit expressions for configuration entropies of atomic and magnetic subsystems with their configuration internal energies. Phase diagram of a system at issue was plotted within the field of the presence of f.c.c.-Ni–Fe alloys; their phase boundaries, equilibrium (static) properties near critical points (order parameter, etc.), and possible microstructures developed by composition-controlled magnetic transitions and/or order–disorder constant-composition solid–solid phase transformations were discussed. The obtained results were compared with available experimental data.
Authors: E.R. Andrievskaya, V.P. Red'ko, V.P. Smirnov, L.M. Lopato
Authors: Мaksim Morozov, Aleksandr I. Potekaev, Anatolii A. Klopotov, Valentina Kulagina, Тatyana Markova, Vladimir D. Klopotov
Abstract: The results of the analysis of phase equilibria ordered phases in binary systems based on palladium Pd-Me (Me = Co, Rh, Ir, Cu, Ag, Au, Ni, Pt) are set out to search for correlations and crystal-chemical and crystal geometric factors. It is found that the packing factor in disordered solid solutions in binary systems based on Pd is close to the value of 0.74 on a background of a slight deviation from the atomic volumes Xena. It is revealed that increasing of the hydrogen permeability in Cu-Pd binary alloys correlates with significant reduction of the packing factor in B2 ordered phase in the range of 40 at.% Pd. It is found that various structural-phase states are formed in Pd-Me binary systems with certain combinations of temperature and size factors.
Authors: A.A. Kodentsov, M.R. Rijnders, F.J.J. van Loo
Authors: W. Kowalski, B. Grushko, Włodzimierz Bogdanowicz, M. Surowiec
Abstract: The Al-Pd-Cr alloy system was investigated at 680 to 990°C in the compositional range above 60 at.% Al. The binary Al-Cr , μ and phases dissolves up to 1 at.% of Al, the η-phase extends up to 2 at.% of Pd and the 2-phase extends up to 3 at.% of Pd, respectively. The binary Al-Pd -phases dissolves up to 3 at.% of Cr and -phase up to 4 at.% Cr. Close to the high-Pd limit of the -range a ternary phase is formed between about Al78Pd4Cr18, Al77Pd10Cr13 and Al74Pd7Cr19. Its structure is orthorhombic with lattice parameters: a = 1.47, b = 1.24 and c = 1.25 nm, resembling the lattice parameters of the high-temperature Al3Mn phase. A hexagonal structure with a = 1.77 and c = 1.25 nm resembling Al-Ni(Cu)-Cr ζ-phase [1-3] was revealed around Al81.5Pd1.5Cr27 and another hexagonal structure with very close lattice parameters around Al73Pd11Cr16. Another ternary phase was found in 970°C around the Al77.5Pd1.5Cr21 composition. It has orthorhombic structure with a = 1.24, b = 3.46 and c = 2.04 nm resembling the ternary -phase in Al-Ni-Cr. An additional orthorhombic phase with a = 2.48, b= 3.87 and c = 2.04 nm was found to be formed between about Al82Pd4Cr14, Al79Pd4Cr17 and Al79Pd9Cr12.
Authors: Yeon Ki Hong, Byung Heung Park
Abstract: A pyroprocessing technology has been developed to process spent nuclear fuels with decreased waste and increased proliferation resistance. A main process of the pyroprocessing is an electrorefining which requires a post-treatment for recovered uranium. A distillation approach is adopted to remove an electrolyte salt residue on the uranium. In this work, the vapor composition of the distillation process and the total pressure were estimated to obtain basic data for process design and integration. Six chlorides including KCl, LiCl, UCl3, PuCl3, CeCl3, and YCl3 were considered to understand the behavior of the representative components of actinides and lanthanides. It was found that small amount of the actinides and lanthanides would be accompanied by the electrolyte salts (KCl and LiCl) during the distillation under high vacuum.
Authors: Jorge A. Gordillo
Abstract: The diffusion of a B element into an A matrix was studied by the random walk theory. Considering that concentration of B element in the A matrix is very low, the jumps of diffusing atoms are independent of each other. The A matrix is a two-region material with different properties, such as a two-phase material, a single crystal with dislocations, or regions influenced by other solute and a polycrystalline material.It is assumed that material B has a penetration that allows it to cross each region of material A several times. This implies that jumps across the surface between those regions have an average frequency and, as a consequence, there is an interdiffusion coefficient between them. The interdiffusion coefficient between those regions is different than the coefficient of the diffusion in each region.Expressions were obtained that allow to delimit the ranges of validation with greater precision than the corrected Hart-Mortlock equation for solute diffusion. In addition, an original relationship was obtained between the segregation coefficient and parameters specific to the diffusion. New powerful tools were also found that can help to understand diffusion in nanocrystalline materials, diffusion in metals influenced by impurities and diffusion produced by different mechanisms.
Authors: H.-G. Hettwer, Nicolaas Stolwijk, Helmut Mehrer
Showing 1 to 10 of 50 Paper Titles