The microstructure evolution and strengthening mechanism of fine-grained Al–Mn alloy with nanoscale precipitates during cryorolling

Abstract

In this work, the fine-grained Al–Mn alloys with nanoscale precipitates was designed, and the texture evolution and strengthening mechanism for fine-grained Al–Mn alloy with nanoscale precipitates during cryorolling were investigated by EBSD and TEM analysis. The results show that the dislocation tangles gradually evolved into dislocation cells, and then into subgrains/ultrafine grains with boosting rolling reduction. The initial grains and precipitates can be significantly refined by cryorolling. Furthermore, the dominating P and M textures in the solution-treated Al–Mn alloy gradually converted to α-fiber and β-fiber textures during cryorolling. The formation of α-fiber and β-fiber textures is beneficial for improving the strength of the Al–Mn alloy. An excellent strength-ductility synchronization can be achieved in the Al–Mn alloy cryorolled at a rolling reduction of 50 %. The strengthening mechanism of Al–Mn alloy subjected to cryorolling is associated with texture strengthening, dislocation strengthening, grain refinement strengthening and precipitation strengthening.