Trapping of point defects in real alloys by considering the effect of short range order

Abstract

Based on the random walk of point defect in concentrated alloys, the kinetics of the annihilation of point defects in a f.c.c. alloy is studied by computer simulation. The effect of the degree of order is especially considered by using the pair model for describing the atomistic interaction. The simulations cover nearly the whole temperature range in which short range order or short range clustering exists. Due to the special treatments, the escape probability for various trap structures (0D or 1D and with different reaction radius) can be determined as a function of the annealing time. Further evaluation yields the trapping time of point defects for broad variation of relevant parameters including the composition of alloy and the mobility ratio of the components. Empirical functions are developed for expressing these dependences.

Compared to the random alloy simplification reported in the preceding paper [1], there is no change in the essential form of the trapping kinetics. The relation between the activation energy for the annihilation of point defects and that for the self-diffusion of atoms in real alloys is revealed, which yields the background for studying the diffusion properties through the investigation of point defect annihilation.