Mechanisms of Strengthening Aluminum Foils Consolidated by High-Pressure Torsion Technique

The contributions of grain boundary and dislocation mechanisms to the experimentally established strengthening of pure Al samples obtained by consolidation of thin foils by high pressure torsion technique were estimated within the framework of well-known theoretical models using structural parameters (sizes of coherently scattering domains and lattice microstrains) determined by X-ray diffraction. Good agreement between the calculated values and the hardness of deformed and aged samples was found, and possible reasons for their differences for the initial foils were discussed. The influence of deformation and aging on the relative contributions of the analyzed mechanisms to the strengthening of samples consolidated from both Al foils and the rapidly quenched Al95.8Mn3.8Fe0.4 ribbons was determined. The structural features of samples processed by high pressure torsion and the relationship between structural parameters and mechanical properties were discussed.