Abstract—

The evolution of the structure and phase composition of the Al–Zn–Mg–Fe–Ni alloy (nikalin) during severe plastic deformation by high pressure torsion and annealing has been investigated using high-resolution TEM techniques. The deformation of the quenched alloy has been found to result in a submicron composite comprising an Al matrix and various fine aluminides. The severe structural refinement takes place along with phase transformations, which dissolve the metastable Al₃Zr-phase particles and cause the nanosized strengthening phases Т (Al₂Mg₃Zn₃) and η' (MgZn₂) to precipitate from the Al solid solution which has been supersaturated in result of quenching and deformation. Nikalin has been determined to retain its submicrocrystalline state during low-temperature annealing (200°C, 4 h) due to the barrier effect of fine hardening phase particles, fixing grain boundaries. High-temperature heating to 400°C for four hours transfers nikalin to the overaged state, in which it is characterized to consist of a recrystallized matrix with grains 2–3 µm in size, eutectic micron-sized aluminides, and stable Al₂Mg₃Zn₃ and MgZn₂-phase particles with sizes of no more or equal to 500 nm.

中文翻译：

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严重塑性变形和退火过程中淬火的Al-Zn-Mg-Fe-Ni合金的组织演变

摘要—

使用高分辨率TEM技术研究了Al-Zn-Mg-Fe-Ni合金（尼克兰）在高压扭转和退火导致的严重塑性变形过程中的结构和相组成的演变。已经发现，淬火合金的变形导致包含铝基体和各种细铝化物的亚微米复合物。伴随相变进行了严重的结构细化，这些相变溶解了亚稳的Al ₃ Zr相颗粒，并导致了纳米级强化相Т（Al ₂ Mg ₃ Zn ₃）和η'（MgZn ₂）从因淬火和变形而过饱和的Al固溶体中沉淀出来。由于精细硬化相颗粒的阻挡作用，固定了晶界，尼古丁已被确定在低温退火（200°C，4 h）期间保持其亚微晶态。高温加热到400°C持续4小时，尼基林会转变为过时状态，其特征在于它由晶粒大小为2-3 µm的重结晶基质，低共熔微米级铝化物和稳定的Al ₂ Mg _3组成。尺寸不大于或等于500 nm的Zn ₃和MgZn ₂相颗粒。