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用包含弹性应变能的微观相场法研究L12-Ni3Al相和D022-Ni3V相在1000K,1200K单温度时效及1000K和1200K交变温度下时效的原子占位。研究表明:从1000K单温度时效经由交变温度时效至1200K单温度时效过程中,L12相中的正位原子NiNi和AlAl及D022相中的正位原子NiNi和Vv的占位几率随时间延长而下降,两种结构中的反位缺陷NiAl,NiV,VNi和AlNi及替代缺陷AlNi,AlV和VNi的占位几率却随时间延长而上升。平衡时的L12相中的NiNi占位几率大于D022相中的NiNi,L12相中的AlAl占位几率小于D022相中的VV,反位缺陷和替代原子在L12相中的占位几率均大于D022相。在交变时效下,原子占位几率的时间演化曲线呈“长城”状,曲线顶点的占位几率值小于相应的单温度时效下的平衡值,但是曲线谷值大于相应的单温度时效下的平衡值。
The microscopic phase field method was used to study the atomic occupancy of L12-Ni3Al phase and D022-Ni3V phase at 1000K, 1200K single temperature aging and 1000K and 1200K alternating temperature. The results show that the occupancy probability of NiNi and Vv of the ortho-atom NiNi and AlAl and D022 in L12 phase increases with time from 1000 K single-temperature aging to 1200 K single-temperature aging , The occupancy odds of NiAl, NiV, VNi and AlNi and substitution defects AlNi, AlV and VNi in the two structures increase with time. The probability of NiNi occupancy in the L12 phase is greater than that in the D022 phase at equilibrium, the AlAl occupancy probability in the L12 phase is less than the VV in the D022 phase, and both the positron-enthalpy and substitutional atom occupancy in the L12 phase are greater than D022 phase. Under alternating aging, the time evolution curve of atomic occupancy probability is “Great Wall” shape. The occupancy probability value at the vertex of the curve is smaller than the corresponding equilibrium value at single temperature aging, but the valley value of the curve is greater than the corresponding single temperature aging Under the balance value.