Ternary diffusion in Cu-Ni-Zn alloys at 1133 K

AbstractThe interdiffusion coefficients in the α fcc phase of Cu-Ni-Zn alloys DZnZnCu, DZnNiCu, DNiNiCu and DNiZiCu at 1133 K have been determined by an extended Boltzmann-Matano method. The major coefficients DZnZnCu and DNiNiCu are positive, and the crosscoefficients DZnNiCuand DNiZnCu are negative. A pronounced concentration dependence of the four interdiffusion coefficients is observed, DZnZnCu being particularly sensitive to composition. From the estimated, values of interaction parameters, it is considered that the interaction energy of the Ni-Zn bond at 1131 K is much larger than the values for the Cu-Zn and Cu-Ni bonds. The tracer diffusion coefficients DZu*, DNi* and DCu* calculated from the equations of Zieboldand Ogilvie are in the order DZu* > DCu* > DNi*. In addition, the calculated intrinsic diffusion coefficients DZnZnCu and DNiNiCu are positive, and the four other coefficients are negative.