Evolution of microstructure, mechanical properties, and corrosion behavior of Al-xMg-Mn alloy plates by rolling treatment

This article presents a systematic study on the synergistic effects of Mg element and rolling on the microstructure, mechanical properties, and corrosion resistance of Al-Mg-Mn alloy. The presence of Mg element leads to the formation of the β-phase (Al3Mg2). In the as-rolled alloy with high Mg content, the continuity of β-phase distributed at grain boundaries or fiber texture boundaries is weakened and its size is refined. This refinement is beneficial for improving the hardness and tensile properties of the alloy. However, it slightly reduces the electrical conductivity, elongation, and corrosion resistance of the alloy. The reasons for these changes in properties are analyzed from the perspective of dislocation motion. Comparing the hot-rolled state alloy with the cold-rolled state alloy, it is found that the corrosion resistance of the latter is improved. This improvement can be attributed to the difficulty of forming a continuous network of β-phase at grain boundaries, which significantly reduces the alloy's corrosion sensitivity. Additionally, the higher strength of the alloy can be attributed to dispersion strengthening and grain boundary strengthening. The objective of this work is to provide a strategy for obtaining Al-Mg-Mn alloy sheets with excellent performance