Magnetic properties evaluation of spray formed and rolled Fe-6.5 wt.% Si-1.0 wt.% Al alloy

The Fe-6.5 wt.% Si alloy is an excellent soft magnetic material. However, it is too brittle to be hot/cold-rolled since its ordered structure induces the formation of dissociated superlattice dislocations and correlated high stress concentrations leading to premature fracture. The addition of aluminum to high silicon electrical steels, combined with high solidification rates of the spray forming process, can alter the kinetics of these ordering transformations offering the possibility to obtain thin sheets through the hot/cold rolling process. The aim of this work was to determine the magnetic properties of spray-formed Fe-6.5 wt.% Si-1.0 wt.% Al alloy in the "as-sprayed" condition and after hot/cold rolling. After annealing at 973 K for 1 h, the best magnetic properties were observed in the rolled samples. This result is due to the elimination of microstructural defects and porosity and the formation of DO3 ordered structure. (c) 2006 Elsevier B.V. All rights reserved.