HIGH-PRESSURE TORSION FOR MICROSTRUCTURE CONTROL IN BINARY Al-Fe ALLOYS WITH DIFFERENT STATES OF Fe-CONTAINING PHASES

High-Pressure Torsion (HPT) is used to process Al-Fe alloys with different initial states of their Fe-containing phases and to study the capability to improve their overall mechanical properties. The samples used in this study include a bulk form of disks with 10 mm in diameter extracted from cast ingots and extruded rods with combinations of prior annealing. In addition, mixtures of high purity powders are processed by HPT to produce the bulk form of disks. Different fractions of Fe are added to control the initial states of the Fe-containing phases. Evolution of microstructures and mechanical properties with straining by HPT is examined using transmission electron microscopy (TEM), X-ray diffraction analysis (XRD), hardness measurements and tensile testing. It is shown that the hardness increases with increasing strain and Fe addition. Second phase particles are fragmented and some dissolution occurs with straining. Formation of intermetallic phases is also confirmed after large numbers of revolutions.