Microscopic Phase Field Study of the Spinodal Decomposition in Fe-Mo Alloys

The spinodal decomposition in Fe-Mo alloys is studied by microscopic phase field method based on atomic scale.The results show that critical temperature of spinodal decomposition increases with the increment of Mo content,up to a maximum value of 1340 K at the Mo content of 50%.The spinodal decomposition shows a maximum rate at the Mo content of 50% for different Fe-Mo alloys.Comparing with the interconnected microstructure without considering elastic strain energy,the microstructure arrayed alternatively along the elastic soft direction of [01] and [10] is obtained under the effects of elastic strain energy,which will changes into a special "macrolattice" structure during subsequent coarsening stages.The coarsening of microstructure is restrained by elastic interaction generated by atomic-size difference,and a larger atomic-size difference induces a stronger restraining effect.