Co-Pt合金中L10原子间相互作用势和沉淀过程的微观相场法研究

Microscropic Phase-field study of the interatomic potential and precipitation process for L10 structure in Co-Pt alloys

摘要:

本文基于微观相场法和原子间相互作用势方程，计算出Co-Pt合金中L10结构第一近邻原子间相互作用势，计算结果得到Co-Pt合金中L10结构第一近邻原子间相互作用势随温度增大而增大，随浓度增大而增大，且计算得到的随温度和浓度变化的原子间相互作用势与之前的实验值符合较好。利用计算的原子间相互作用势模拟了Co-Pt合金沉淀过程以及最终形貌，模拟结果能得到L10和L12结构，根据序参数可以得到L10结构的沉淀转变机制特征是失稳分解，而后粗化长大且最终两相体积分数接近，合金沉淀形貌与实验结果符合。相场法计算Co-Pt合金中L10结构原子间相互作用势，拓展了相场法在含L10结构的合金设计中的应用范围。

Abstract:

Based on the Microscropic Phase-field method and the interatomic potential equation, we calculate the first near-neighbor interatomic potentials of the L10 structure in Co-Pt alloy, and the results show that the first near-neighbor interatomic potential of the L10 structure in the Co-Pt alloy increases with temperature, and increases with concentration. The first near-neighbor interatomic potential, which linearly changes with the temperature and concentration, is close to other literature result. Using the interatomic potential to simulate the Co-Pt alloy precipitation process and the final morphology, the simulation results can get L10 and L12 structure. According to the sequence parameters, we can get that the L10 structure precipitation mechanism characteristics are spinodal decomposition, and then coarsed. The final two-phase volume fraction is close and the alloy precipitation profile and experimental results are consistent. The calculation of the interatomic potential for L10 structure in Co-Pt alloy using Phase-field method can expand the application range of Phase-field method in alloy design with L10 structure.