Structure modification of rapidly solidified Al-11 wt% Si alloy by the addition of 2 wt% Fe

摘要

An investigation of the structure formation of as-cast Al-11wt% Si (AlSi11) and Al-11wt% Si-2wt% Fe (AlSi11Fe2) rapidly solidified (RS) ribbons is performed. Ribbon samples are examined in detail using Auger electron spectroscopy (AES) and transmission electron microscopy (TEM). A nanoscale thickness layer of Si-precipitations, at both M-grains boundary and oxide/Al-matrix interface, is found to be characteristic for "pure" AlSi11 ribbons. For Fe-doped ribbons, this layer comprises Fe-containing phase also, which appears to possess amorphous nature and is situated between the Si-grains and Al-matrix. A possible mechanism of altering the thermally activated volume diffusion of elements, due to the effect of Fe on the structure modification, is speculated based on the obtained results. (c) 2007 Elsevier Ltd. All rights reserved.