Diffusion of carbon in cobalt

Abstract

Diffusion coefficients of carbon in cobalt have been determined by the residual activity method with radioactive tracer 14C in the temperature range between 976 and 1673 K. Above the Curie temperature (1396 K), the diffusion coefficient shows a linear Arrhenius relationship. Below the Curie temperature, temperature dependence of the diffusion coefficient deviates from the linear Arrhenius relationship owing to the magnetic spin ordering. Taking into account the influence of the magnetic transformation on diffusion, the temperature dependence of the diffusion coefficient, D, in the whole temperature range across the Curie temperature can be expressed by (Formula omitted.) m2 s−1, where s is the ratio of the spontaneous magnetization in cobalt at T K to that at 0 K. © 1989, The Japan Institute of Metals. All rights reserved.