双级复相Ni_3Al-Ni_3V合金时效过程的微观相场模拟

Microscopic Phase-field Simulation of Aging Process of Dual Two-phase Ni_3Al-Ni_3V Intermetallic Alloy

利用微观相场法模拟了新型Ni3Al(L12)-Ni3V(D022)双级复相金属间化合物合金的时效过程。结果表明:高温(1370 K)时效阶段形成上级结构L12+A1(Ni基固溶体),尺度为微米级;共析温度以下(1200 K)时效阶段形成下级结构L12+D022,尺度为亚微米级,两级时效处理后形成L12+(L12+D022)双级复相微观结构。低温时效阶段,在D022相析出所产生的弹性势作用下,D022/L12相界面由{001}转向{011},{011/2}型界面在时效末期数量占优,最终下级复相组织中的D022相与L12相呈层状相间分布。

Microscopic phase field method was employed to simulate the aging process of Ni3Al （L12）-Ni3V （D0_22） dual two-phase intermetallic alloy. The results show that the upper two-phase microstructure with a micron scale consisting of the prior A1 （Ni solid solution） and L12 phases are formed through high-temperature （1370 K） aging stage; prior A1 phase is decomposed into L12＋D0_22 by a eutectoid reaction at low temperature（1200 K）, resulting in the lower two-phase microstructure with a sub-micron scale, dual two-phase microstructure of L12＋（L12＋D0_22） is formed finally. Due to the elastic potential caused by precipitation of D0_22~ phase, DO_22/L12 interfacial plane rotates from {001 } to {011 } duing low-temperature aging stage and {011/2} dominate at last, the morphology of the lower two-phase microstructurepresents a lamellar-like form composed of L12 and D0_22 phases.