X-ray Peak Profile Analysis on the Microstructure of Al-5.9Mg-0.3Sc-0.18Zr Alloy Deformed by High Pressure Torsion Straining

摘要

The microstructure of plastically deformed Al-5.9%Mg-0.3%Sc-0.18%Zr alloy has beenudinvestigated. The severe plastic deformation has been performed by high pressure torsionudstraining (HPT) up to 15 revolutions at room temperature. The microstructure as a function ofudthe number of revolutions is studied by X-ray diffraction peak profile analysis. It is concludedudthat the HPT technique results in nanostructure even after 0.5 turn with very high dislocationuddensity. The crystallite size decreases and the dislocation density increases with the number ofudrevolutions, however, after five turns they go into saturation. The edge and the dipoleudcharacter of the dislocation structure becomes stronger with the increase of the number ofudrevolutions. The value of the crystallite size determined by X-ray peak profile analysis is a bitudsmaller than the grain size obtained by transmission electron microscopy (TEM).