Microscopic phase field simulation for 3-D stress orienting effect of D0₂₂-Ni₃(V, Al) in precipitation process

D0₂₂ phase is the main strengthening phase in Ni-Al-V alloy applied at high temperature and structure transformation from fcc to D0₂₂during the ordering process has been investigated extensively. The 3-D stress orienting effect of D0₂₂-Ni₃(V, Al) was studied using microelastical phase field model in this work. The results indicate that D0₂₂ particles tend to grow along stress soft direction of [100] and be depressed along [001] which means the growing direction is perpendicular to c-axes of D0₂₂ phase, and the layer D0₂₂ microstructure is formed due to the way they grows. The fcc matrix transforms into three D0₂₂variants during the early stage and then the strain field of D0₂₂ and L1₂particles generates elastic interaction which leads to variants deletion. Different D0₂₂ variants assort and compete with each other during precipitation process, and D0₂₂-variant III disappears while D0₂₂-variantIdominates in the end.