Ternary interdiffusion in L12–Ni3Al with ternary alloying additions of Ir and Ta was investigated at 1473K using solid/solid diffusion couples. Average ternary interdiffusion coefficients were deduced from an integration of the interdiffusion fluxes calculated directly from experimental concentration profiles. The magnitudes of the DNiNi and DAlAl coefficients (table 3) were found to be much larger than those of DIrIr and DTaTa (table 4). Iridium which substituted on Ni-sites significantly influenced the interdiffusion of Ni, and the DNiIrAl coefficients were found to be large and positive (table 5). However, Ta substituting for Al significantly influenced the interdiffusion of Al, and the DAlTiNi coefficients were determined to be large and positive. Excellent agreement was found with ternary interdiffusion coefficients determined by Boltzmann–Matano analysis. Profiles of concentrations and interdiffusion fluxes indicated binary interdiffusion coefficients and tracer diffusion coefficients of Ir (14.7 x 10−16m2/s) and Ta (2.6 x 10−16m2/s).
Effects of Ir or Ta Alloying Addition on Interdiffusion of L12–Ni3Al. Garimella, N., Ode, M., Ikeda, M., Murakami, H., Sohn, Y.H.: Intermetallics, 2008, 16[9], 1095-103
Table 4
DIrIr Interdiffusion coefficients in Ni-Al-Ir alloys at 1473K
Couples | Coefficient | Value (m2/s) |
Ni-25Al/Ni-23Al-3Ir + Ni-24Al/Ni-24Al-2Ir | DIrIrNi | 1.25 x 10-15 |
Ni-25Al/Ni-23Al-3Ir + Ni-24Al/Ni-24Al-2Ir | DIrIrAl | 5.24 x 10-15 |
Ni-25Al/Ni-23Al-2Ir + Ni-25Al/Ni-23Al-3Ir | DIrIrNi | 1.72 x 10-15 |
Ni-25Al/Ni-23Al-2Ir + Ni-25Al/Ni-23Al-3Ir | DIrIrAl | 1.88 x 10-15 |
Ni-26Al/Ni-23Al-2Ir + Ni-25Al/Ni-23Al-3Ir | DIrIrNi | 1.73 x 10-15 |
Ni-26Al/Ni-23Al-2Ir + Ni-25Al/Ni-23Al-3Ir | DIrIrAl | 1.73 x 10-15 |
Ni-24Al/Ni-24Al-2Ir + Ni-25Al/Ni-23.5Al-1Ir | DIrIrNi | 1.15 x 10-15 |
Ni-24Al/Ni-24Al-2Ir + Ni-25Al/Ni-23.5Al-1Ir | DIrIrAl | 1.16 x 10-15 |
Ni-24Al/Ni-24Al-2Ir + Ni-25Al/Ni-23Al-2Ir | DIrIrNi | 2.59 x 10-15 |
Ni-24Al/Ni-24Al-2Ir + Ni-25Al/Ni-23Al-2Ir | DIrIrAl | 2.59 x 10-15 |
Ni-25Al/Ni-23Al-2Ir + Ni-24.5Al/Ni-24.5Al-1Ir | DIrIrNi | 1.10 x 10-15 |
Ni-25Al/Ni-23Al-2Ir + Ni-24.5Al/Ni-24.5Al-1Ir | DIrIrAl | 2.60 x 10-15 |
Ni-25Al/Ni-23Al-2Ir + Ni-24.5Al/Ni-24.5Al-1Ir | DIrIrNi | 1.52 x 10-15 |
Ni-25Al/Ni-23Al-2Ir + Ni-24.5Al/Ni-24.5Al-1Ir | DIrIrAl | 1.52 x 10-15 |
Ni-25Al/Ni-23Al-3Ir + Ni-25Al/Ni-23.5Al-1Ir | DIrIrNi | 1.37 x 10-15 |
Ni-25Al/Ni-23Al-3Ir + Ni-25Al/Ni-23.5Al-1Ir | DIrIrAl | 1.37 x 10-15 |
Ni-25Al/Ni-23.5Al-1Ir + Ni-24.5Al/Ni-24.5Al-1Ir | DIrIrNi | 1.20 x 10-15 |
Ni-25Al/Ni-23.5Al-1Ir + Ni-24.5Al/Ni-24.5Al-1Ir | DIrIrAl | 1.21 x 10-15 |
Table 5
DNiIrAl Interdiffusion coefficients in Ni-Al-Ir alloys at 1473K
Couples | DNiIrAl (m2/s) |
Ni-25Al/Ni-23Al-3Ir + Ni-24Al/Ni-24Al-2Ir | 9.839 x 10-14 |
Ni-25Al/Ni-23Al-2Ir + Ni-25Al/Ni-23Al-3Ir | 5.122 x 10-14 |
Ni-26Al/Ni-23Al-2Ir + Ni-25Al/Ni-23Al-3Ir | 5.800 x 10-14 |
Ni-24Al/Ni-24Al-2Ir + Ni-25Al/Ni-23.5Al-1Ir | 6.264 x 10-14 |
Ni-24Al/Ni-24Al-2Ir + Ni-25Al/Ni-23Al-2Ir | 5.110 x 10-14 |
Ni-25Al/Ni-23Al-2Ir + Ni-24.5Al/Ni-24.5Al-1Ir | 6.066 x 10-14 |
Ni-25Al/Ni-23Al-2Ir + Ni-24.5Al/Ni-24.5Al-1Ir | 7.841 x 10-14 |
Ni-25Al/Ni-23Al-3Ir + Ni-25Al/Ni-23.5Al-1Ir | 6.362 x 10-14 |
Ni-25Al/Ni-23.5Al-1Ir + Ni-24.5Al/Ni-24.5Al-1Ir | 7.056 x 10-14 |