The processes of elastic and plastic deformation of materials are considered within the framework of the acoustoplastic effect. A model proposed is based on the processes of defect formation during the deformation of materials according to the activation mechanism. The dynamic equations for the formation of defects are considered in view of the change in their activation energy caused by the defect interaction. It is shown that by comparing experimental data with the obtained theoretical results, it is possible to obtain information about such characteristics of materials as the concentration of defects, their relaxation time, the nature of interaction, and internal friction stress. These parameters were obtained for aluminum and copper alloy M1. Keywords: metal deformation, defects, mechanical stress, activation volume.