Dislocation evolution and induced precipitation on corrosion resistance of a novel Al-Mg-Zn-Er-Zr alloy during hot compression

Al-Mg-Zn-Er-Zr alloy was compressed in temperature range from 300 to 500℃ to investigate the microstructure evolution.Molecular dynamics simulations were used to study the mechanical behavior and dislocation evolution.The results showed that mobile dislocations are widely distributed in alloys and make important contributions to coordinate compressive deformation.The sessile dislocations hinder the deformation,and the content is about 1/20 of that of mobile dislocations.Continuous dynamic recrystallization(CDRX) is considered to be the main recrystallization mechanism.The accumulation of dislocations can provide element diffusion channels and driving force for τ(Mg32[Al,Zn]49) phase precipitation,resulting in the forced precipitation of discontinuous τphase to replace the continuous β phase(Al3Mg2),which reduces the corrosion potential,resulting in increased corrosion resistance.