Mechanical anisotropy and microstructural changes during cryorolling of Al–Mg–Si alloy

Abstract

Rolling was performed on Al–Mg–Si alloy sheets to true strain values of 0.69 and 1.38 at both room temperature and at cryogenic (liquid nitrogen) temperature and the influence of rolling temperature on microstructure and mechanical properties was studied. At both the reductions, cryorolled samples exhibited enhanced hardness and strength compared to room temperature rolled samples. The enhanced properties of cryorolled samples are attributed to the high dislocation density, increased microstrain and a reduced crystallite size compared to room temperature rolled samples. Besides, at high true strain condition, anisotropy behaviour was studied and correlated with X-ray bulk texture components. Evaluation of the percentage volume fraction of individual texture components revealed that cryorolled samples exhibited ~16% and ~33% increase in S and brass deformation texture components, respectively compared to room temperature rolled samples. Cryorolled samples also showed an enhanced texture index value compared to room temperature rolled samples.