Effe-as of Ir or Ta alloying addition on interdiffusion of L1(2)-Ni3Al

    Authors

    N. Garimella; M. Ode; M. Ikeda; H. Murakami;Y. H. Sohn

    Comments

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    Abbreviated Journal Title

    Intermetallics

    Keywords

    nickel aluminides, based on Ni3Al; diffusion; site occupancy; electron; microprobe; ZERO-FLUX PLANES; MULTICOMPONENT DIFFUSION COUPLES; MODIFIED ALUMINIDE; COATINGS; CRYSTAL SUPERALLOY TMS-82+; NI-AL SYSTEM; CONCENTRATION-DEPENDENCE; IRREVERSIBLE-PROCESSES; RECIPROCAL RELATIONS; OXIDATION BEHAVIOR; TERNARY ADDITIONS; Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy &; Metallurgical Engineering

    Abstract

    Ternary intercliffusion in L1(2)-Ni3Al with ternary alloying additions of Ir and Ta was investigated at 1473 K using solid-to-solid diffusion couples. Average ternary intercliffusion coefficients were determined from an integration of interdiffusion fluxes calculated directly from experimental concentration profiles. The magnitude of (D) over cap (NiNi) and (D) over cap AlAl coefficients was determined to be much larger than that of (D) over cap IrIr and (D) over cap TaTa coefficients. Ir substituting in Ni-site influenced the intercliffusion of Ni significantly, and (D) over cap (Al)(NiIr) coefficients were determined to be large and positive. On the other hand, Ta substituting for A] influenced the interdiffusion of Al significantly, and (D) over cap (Ni)(AlTa) coefficients were determined to be large and positive. An excellent agreement was found with ternary interdiffusion coefficients determined by Boltzmann-Matano analysis. Profiles of concentrations and intercliffusion fluxes were also examined to estimate binary intercliffusion coefficients in Ni3Al, and tracer diffusion coefficients of IF (14.7 x 10(-16) 1.4 x 10(-16) m(2)/s) and Ta (2.6 x 10(-16) 2.4 x 10(-16) m(2)/s) in Ni3Al. (C) 2008 Elsevier Ltd. All rights reserved.

    Journal Title

    Intermetallics

    Volume

    16

    Issue/Number

    9

    Publication Date

    1-1-2008

    Document Type

    Article

    Language

    English

    First Page

    1095

    Last Page

    1103

    WOS Identifier

    WOS:000259847900008

    ISSN

    0966-9795

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