On the effect of ECAP and subsequent cold rolling on the microstructure and properties of electromagnetically cast Al–Fe alloys

Abstract

The application of the electromagnetic casting (EMC) to aluminum alloys is capable of producing structures, hardly obtainable by the conventional methods of casting due to the constant stirring of the crystallizing alloy and high cooling rate (∼103 K/s). For the first time we study EMC high purity binary Al-0.5Fe and Al-2.5Fe (wt.%) alloys in the as-cast state as well as after equal-channel angular pressing (ECAP) and cold rolling (CR). We demonstrate that EMC process leads to formation of metastable Al2Fe-alike intermetallic phase which does not decompose by further straining and annealing. Combined deformation by ECAP and CR results in the formation of ultrafine grained structure in which providing the increase in ultimate tensile strength up to 200 MPa in Al-0.5Fe and up to 340 MPa in Al-2.5Fe. Electrical conductivity level of Al-0.5Fe alloy increases up to 58.5% IACS, while the conductivity of Al-2.5Fe alloy decreases to 47.9% IACS. Both alloys demonstrate thermal stability of microstructure, mechanical and electrical properties under annealing up to 230 °C for 1h. These effects are discussed in terms of as-cast and strain-induced microstructures.