Morphological evolution and strengthening behavior of α-Al(Fe, Mn) Si in Al-6Si-2Fe-xMn alloys

beta-Al5FeSi is preferred to form in Al-Si-Fe alloys, normally exhibiting needlelike, which is harmful for the mechanical properties. In this paper, with the addition of 1%, 1.5% and 3% Mn into an Al-6Si-2Fe alloy, b-Al5FeSi phase was found to transform to skeleton, flower-like and coarse dendritic alpha-Al(Fe, Mn) Si, respectively. The novel flower-like alpha-Al(Fe, Mn) Si crystals contain developed branches with the average diameter of similar to 200 nm, performing strengthening effect on the tensile property. Detailed morphologies of alpha-Al(Fe, Mn) Si phase and the formation mechanism were discussed. (C) 2017 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license.