Ternary interdiffusion in L12-Ni3Al with ternary alloying additions of Ir and Ta was investigated at 1473 K using solid-to-solid diffusion couples. Average ternary interdiffusion coefficients were determined from an integration of interdiffusion fluxes calculated directly from experimental concentration profiles. The magnitude of over(over(D, ̃), -)NiNi and over(over(D, ̃), -)AlAl coefficients was determined to be much larger than that of over(over(D, ̃), -)IrIr and over(over(D, ̃), -)TaTa coefficients. Ir substituting in Ni-site influenced the interdiffusion of Ni significantly, and over(over(D, ̃), -)NiIrAl coefficients were determined to be large and positive. On the other hand, Ta substituting for Al influenced the interdiffusion of Al significantly, and over(over(D, ̃), -)AlTaNi 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 interdiffusion fluxes were also examined to estimate binary interdiffusion coefficients in Ni3Al, and tracer diffusion coefficients of Ir (14.7 × 10-16 ± 1.4 × 10-16 m2/s) and Ta (2.6 × 10-16 ± 2.4 × 10-16 m2/s) in Ni3Al.
ASJC Scopus subject areas
- 化学 (全般)