Ni基-Mn-Cu3元系固溶体中の相互拡散

Abstract

The interdiffusion coefficients in a Ni base-Mn-Cu ternary system have been determined by the method after A. Brunsch et al. at a constant temperature of 1173 K, and the atomic mobilities of these elements have been calculated using Dayananda’s method. The results obtained from this experiment are as follows:(1) The direct interdiffusion coefficients (DMnNiNi, DMnCuCu) and the cross interdiffusion coefficients (DMnNiCu, DMnCuNi) have shown strong concentration dependency; particulaly the interdiffusion coefficients DMnNiNi which are extrapolated to CCu→0 are consistent with those obtained from the other experiment for a Ni-Mn binary alloy system.(2) The Kirkendall effect is observed in this ternary alloy system; the marker interface always moves towards the lower nickel concentration side, and the diffusion fluxes at the marker interface containing Ni-(4.9∼20.5 at%)Mn-(5.3∼20.3 at%)Cu are related to JMn+JCu>JNi. The atomic mobilities of these elements calculated from Dayananda’s method at the above-mentioned marker position increase in the order of Cu, Ni and Mn, where it is assumed that Henry’s law is maintained in this ternary alloy system.