Stress Relaxation in Magnesium at Low Temperatures

Abstract

Abstract Logarithmic stress relaxation in polycrystalline magnesium of 99.999% purity was studied at strains of up to 4% at 77‐295 °K. The energy barrier of 0.74 ± 0.05 eV, associated with the relaxation, was found to be numerically equal to that known to control the temperature dependence of the flow stress of magnesium single crystals in simple glide. The observations are explained on the assumption that the relaxation arises from residual glide of basal dislocations impeded by the frictional drag of elementary intersection jogs.