Investigation of Compression Resistance and Microstructure Evolution of Al–5Mg–2Si Alloys Based on Mn Alloying

This study systematically investigates the effect of Mn alloying on the microstructure and compressive properties of the Al–5Mg–2Si alloy. Microstructural characterization was performed using scanning electron microscope, transmission electron microscope, and electron backscatter diffraction, while mechanical behavior was evaluated under both quasistatic and dynamic compression via universal testing machine, and split Hopkinson pressure bar. Under static compression, the Mn‐containing alloy exhibits higher strength than the Mn‐free alloy at the same displacement. During dynamic compression testing, the peak stress and peak strain of the alloys all increased with increasing strain rate. As the strain rate increased from 900 to 2900 s −1 , the peak stress of the Al–5Mg–2Si–Mn alloy increased from 301 to 502 MPa, and the peak strain increased from 0.036 to 0.174. Compared with the Mn‐free alloy, the Mn‐containing alloy exhibited higher peak stress but lower peak strain under dynamic loading conditions. This phenomenon is attributed to the solid‐solution strengthening effect of Mn and the effective pinning of dislocations by the α‐Al(Fe, Mn)Si phase during deformation.