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

The contributions of the grain boundary and dislocation mechanisms to the experimentally established strengthening of pure Al samples obtained by the consolidation of thin foils by the high-pressure-torsion technique are 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 the deformed and aged samples is found, and possible reasons for their differences in the initial foils are 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 rapidly quenched Al_95.8Mn_3.8Fe_0.4 ribbons is determined. The structural features of samples processed by high-pressure torsion and the relationship between the structural parameters and mechanical properties are discussed.