No abstract

A model is developed to describe the microstructure evolution during aging a Fe-Cu alloy. The precipitation process during aging a predeformed Fe-1.5 wt pct Cu is calculated and the kinetic details of aging are discussed. The model is satisfactorily tested by comparing with the reported experimental results. The numerical results demonstrate that the nucleation of the precipitates occurs on dislocations first. However, the maximum nucleation rate of the precipitates in the matrix is much higher than that on dislocations and it is not affected by the appearance of dislocations. Only a small fraction of precipitates locate on dislocations immediately after nucleation. The particles in the matrix dissolve preferentially during coarsening, and most of the remained precipitates locate on dislocations in an overaged sample. Dislocations have little effect on the number density and average radius of the precipitates in the late stage of aging, although they promote the beginning of precipitation in the early stage of aging. The heating rate of the specimen almost does not affect the summit of the particle number density as well as its corresponding mean particle radius.