Diffusion of Cobalt into Iron-Cobalt Alloy

Abstract

The diffusivities of CO⁶⁰ into 50–50 atomic percent iron-cobalt alloy were measured by means of the lathe sectioning method for the temperature range including f.c.c. to b.c.c. phase transformation. The experimental values were expressed by
D=1.1×10⁻⁴exp (−41800⁄RT) cm²/sec for f.c.c. structure,
D=2.6×10⁻⁶exp (−27400⁄RT) cm²/sec for f.c.c. structure.
The activation energies for diffusion in the b.c.c. and f.c.c. lattices were compared with the theoretical values calculated by the approximation of the closed shell repulsion with the Born-Mayer potential. And it is concluded that the vacancy mechanism is responsible for the diffusion in the body centered cubic metal in the same manner as in the face centered cubic metal.