Microstructure Evolution in the Near-Surface Region During Homogenization of a Twin-Roll Cast AlFeMnSi Alloy

作者：Wang Junjie; Zhou Xiaorong^*; Thompson George E; Hunter John A; Yuan Yudie

来源：Metallurgical and Materials Transactions A-Physical Metallurgy and Materials Science, 2016, 47A(8): 4268-4275.

DOI：10.1007/s11661-016-3568-6

A near-surface deformed layer, comprising ultrafine grains of 50-500 nm diameters with the grain boundaries being decorated by a high population density of fine cubic alpha-Al-15(FeMn)(3)Si-2 dispersoids and oxide/lubricant particles, was generated in a foil stock AlFeMnSi alloy during twin-roll casting due to severe shear deformation within the near-surface region. During a subsequent multi-step homogenization treatment at temperatures in the range of 713 K and 853 K (440 A degrees C and 580 A degrees C), the fine cubic alpha-Al-15(FeMn)(3)Si-2 dispersoids within the near-surface layer were dissolved, while sparse, large lath-shaped Al3Fe particles formed in the same region. Significant grain growth took place within the near-surface layer due to the loss of grain boundary pinning by the dispersoids, leading to the removal of the ultrafine-grained microstructure within the near-surface region. However, at local regions where the population density of oxide particles was sufficiently high to provide grain boundary pinning, the ultrafine-grained microstructure was preserved within the near-surface layer.

• 出版日期2016-8