Deformation behaviour of iron-rich iron-aluminium alloys at high temperatures

The deformation behaviour of binary monocrystalline and polycrystalline Fe-Al alloys with Al contents up to 18 at.% and only low unavoidable impurity contents-in particular less than 100 wt.ppm C-has been studied above room temperature up to 800 degreesC. The effects of quenching and annealing treatments on the behaviour of as-cast materials were investigated in order to clarify the dependence of strength and ductility on Al content and possible short-range ordering. Besides solid-solution hardening by Al, serrated yielding and deformation twinning were observed at high temperatures. Yielding is affected by quenched-in excess vacancies. (C) 2003 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.