Microstructural dependence of vacancy diffusion in ordered alloys
The dependence of the vacancy diffusional correlation factor on microstructure was investigated by Monte Carlo simulations (MCS). The MCS used activated state rate theory to model the vacancy diffusion. We varied the temperature, size of ordered domains, and the state of order within the domains. Correlations in the vacancy movement were found to vary widely, and numerical values are presented. Two different results were obtained, one for ordering in a homogeneous alloy and another for ordering in an alloy having domains. However, given the existence of domains, the vacancy correlation factor was observed to be independent of domain size. Oscillations in the correlation function were observed, and were attributed to pair trapping of the vacancy.
© 1994 American Institute of Physics. Received 10 June 1993; accepted 25 October 1993. The authors acknowledge stimulating conversations with Dr. L. Anthony and M. Li. This work was supported by the U. S. Department of Energy under contract DE-FG03-86ER45270.
Published - LINjap94.pdf