HIGH-STRENGTH AND HIGH-STIFFNESS AL-FE-MN ALLOYS FABRICATED BY DOUBLEMECHANICAL ALLOYING

High-strength and high-stiffness Al-x%Fe-4%Mn (3< x <6wt-%) alloys hav e been produced by the double mechanical alloying process (dMA) which first involves mechanical alloying (MA1) followed by heat treatment, s econdly mechanical alloying (MA2), and finally hot extrusion. The prep aration of a composite powder with finely distributed intermetallics a nd inert dispersoids by means of this process is described in detail, and the microstructural evolution during the process is also assessed. After extrusion, the alloys show an elevated strength and stiffness a t ambient as well as at high temperatures, due to the distribution of a high content of intermetallics and stabilization of the matrix by in ert dispersoids.