Abstract
The interdiffusion coefficients, \ ildeD, in a Ni-Mn binary alloy system have been determined by the Boltzmann-Matano method in the temperature range from 1073 to 1323 K for various couples consisting of pure nickel and Ni-(10∼40 at%)Mn alloys. Logarithm of \ ildeD increased linearly with the manganese content up to 35 at%Mn which was the upper limit of this experiment, while the activation energies and the frequency factors for interdiffusion decreased monotonously with manganese content. On the other hand the intrinsic diffusion coefficients, DMn and DNi, have been determined mainly by using Darken’s relation, showing that the diffusion of manganese atoms was twice or three times as fast as that of nickel atoms at the composition of 19.7±0.4 at%Mn. Furthermore, the intrinsic diffusion coefficients of them have been determined for reference by using Dayananda’s thermodynamical analysis, showing that the results according to his method were a little smaller than those of the above mentioned Darken’s analysis.
