Aluminum Al-Mg alloys are widely used in the automotive and aircraft industries due to a combination of the strength, good plasticity, and corrosion resistance. An increase in the magnesium percentage increases the strength of the material with insignificant decrease in plastic characteristics. The features of the behavior of the critical stresses in these materials observed as the strain rate increases have been studied. The possibility of predicting critical dynamic stresses in the materials is discussed using the structural-temporal approach.