Effe-as of Ir or Ta alloying addition on interdiffusion of L1(2)-Ni3Al
Abbreviated Journal Title
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
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.
"Effe-as of Ir or Ta alloying addition on interdiffusion of L1(2)-Ni3Al" (2008). Faculty Bibliography 2000s. 353.