Cu-Fe-Co合金双結晶の粒界に析出したBCC Fe-Co粒子の成長

抄録

The growth of BCC Fe-Co boundary particles has been examined for various [011] symmetric tilt and twist boundaries in Cu-Fe-Co bicrystals aged at 723, 748 and 773 K. Except for some specific tilt and twist boundaries in bicrystals aged at 773 K, the particle growth obeys a relationship of the form \barrⁿ=Kt (where \barr is the mean radius, K is a constant and t is the aging temperature) with n=4, as predicted by growth theories of boundary particles. For the special boundaries, n has a value between 3 and 4. The result can be interpreted by considering the relative amount of solute movement along the boundary by grain-boundary diffusion and through the matrix by bulk diffusion. It is found that, for the two types of grain boundary, the activation energy for the particle growth on a boundary shows a good correlation with the energy of the boundary. That is, a lower-energy boundary has a lower diffusivity.