Nanodispersoids of the quasicrystalline Ⅰ-phase in Mn- and Mg-bearing aluminum-based alloys

摘要

The current study compares Al-Mn and Al-Mn-Mg alloys' precipitation behavior in a temperature range of 350-450 degrees C. Mn-bearing nanodispersoids of the quasicrystalline-structured I-phase precipitate during the decomposition of supersaturated Al-based solid solution in both alloys. In the binary Al-Mn alloy, quasicrystalline-structured dispersoids precipitate only in the grain boundaries. The Mg addition does not change the dispersoids' composition but significantly accelerates the precipitation kinetics. The Mg addition provides the precipitation of high-density distributed I-phase nanodispersoids in the body of the grains. The annealing temperature increase results in the I-phase transformation to a cubic a phase, with both phases coexisting in the alloy structure. (c) 2020 Elsevier B.V. All rights reserved.