Nucleation and growth of second-phase precipitates under quenching and annealing

作者：Massih A R^*; Jernkvist L O

来源：Computational Materials Science, 2007, 39(2): 349-358.

DOI：10.1016/j.commatsci.2006.07.006

• non-isothermal precipitation
• zirconium alloys

The Langer-Schwartz equations for precipitation are formulated to calculate nucleation, growth and coarsening of second-phase precipitates under non-isothermal situations. A field-theoretic steady-state nucleation rate model is used in the analysis. The field-theoretic nucleation rate is compared with the classical nucleation rate relation. The results of our model calculations are compared with experiments on the precipitation of cobalt particles in Cu-Co alloys under isothermal conditions. This integrated model is then used to simulate a body-centered cubic to hexagonal closed-packed phase quenching and subsequent annealing steps in the hcp phase of a dilute zirconium alloy, where the mean precipitate size, the number density and the degree of supersaturation are calculated as a function of time. The influence of cooling rate on the aforementioned parameters is evaluated. A lower cooling rate results in larger precipitates with a smaller number density in concordance with observations.

• 出版日期2007-4