EFFECTS OF DIFFERENCE IN ELASTIC-MODULI BETWEEN CONSTITUENTS ON SPINODAL DECOMPOSITION PROCESSES

Computer simulations on the spinodal decomposition processes in a bcc binary alloy with a crystal anisotropy were carried out by using a Monte Carlo method combined with a static variational method. The Johnson-type potentials were used for the interaction between the constituent elements in the alloy. We assumed that the elastic modulus of the precipitate was equal to or softer than that of the matrix. In the former case, the wave number (k(m)) corresponding to the maximum in the structure functions along [100] direction was constant during the initial stage of decomposition, while in the latter case, k(m) decreased with time and the structure functions showed a scaling behavior. Furthermore, only in the latter case, a giant cluster of solute atoms was formed and created a percolative structure at the later stages of aging of the alloy.