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建立耦合非均匀弹性能的微观相场动力学模型,研究了Fe-Al合金匀相转变过程中微观组织演化和动力学行为。结果表明:在非均匀长程弹性交互作用能的影响下,Fe-Al合金时效过程中发生调幅分解与有序化共存相变,形成细小的调幅分解与有序化共存组织。在时效初期,合金中先迅速发生失稳有序化转变,在这个过程中长程序参数(有序度)逐渐增加,形成单一的粗大有序相并在相界上分布着少量无序相。随着时效时间增加,在有序相内部发生调幅分解,浓度起伏逐渐增大直至平衡,形成原子富集区和贫集区,呈现调幅分解与有序化共存。在这个过程中,长程序参数和浓度序参数连续增加,在时效后期趋于稳定。比较模拟结果和试验结果,发现模拟结果的调幅分解与有序化共存组织形态与试验结果相一致,尺寸略小。
The kinetic model of microscopic phase field coupling with nonuniform elastic energy was established and the microstructure evolution and kinetics behavior during the homogeneous transformation of Fe-Al alloy were studied. The results show that under the influence of the non-uniform long-range elastic interaction energy, the AM-decomposition and the ordered co-exchanging phase change during the aging process of Fe-Al alloy, and the formation of small amplitude-modulated decomposition and ordered coexistence occurs. In the early stage of aging, the instability transformation rapidly occurs rapidly in the alloy. In this process, the long program parameters (order degree) gradually increase to form a single coarse ordered phase and a small amount of disordered phase on the phase boundary. As the aging time increases, the amplitude modulation decomposition occurs within the ordered phase, and the concentration fluctuation gradually increases until the equilibrium exists, forming the atomic enrichment zone and the poor accumulation zone, presenting the coexistence of amplitude modulation decomposition and ordering. In this process, parameters of long program and concentration order continuously increase, and tend to be stable in later period of aging. Comparing the simulation results with the experimental results, it is found that the amplitude-decomposition and the ordered coexistence of the simulation results are consistent with the experimental results, and the size is slightly smaller.