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

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 alpha-fiber and 8 -fiber textures during cryorolling. The formation of alpha-fiber and 8 -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.