D022型Ni3(V,Al)相沉淀过程中应力取向效应的微观相场模拟

Microscopic Phase Field Simulation for 3-D Stress Orienting Effect of D022-Ni3(V,Al) in Precipitation Process

摘要:

应用耦合共格弹性畸变的微观弹性相场法研究D022型Ni3(V,Al) 相沉淀过程中的应力取向效应。结果表明，在弹性内应力作用下，D022沉淀相表现出明显的位向性：相颗粒倾向于沿应力软方向[100]生长而在[001]方向受抑制，即生长方向与长轴[001]方向垂直，D022相最终沉淀形貌呈“层”状；沉淀过程中三类D022相变体相互协调以减小共格畸变能，最终D022-variant Ⅲ消失，存留的两类中D022-variant Ⅰ体积比占优。

Abstract:

D022 phase is the main strengthening phase in Ni-Al-V alloy applied at high temperature and structure transformation from fcc to D022 during 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 D022 variants during the early stage and then the strain field of D022 and L12 particles 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.