About Physical Aspects of Increasing Durability of Aluminum Alloys Due to Impact-Oscillatory Loading

Two physical mechanisms that contribute to increasing the fatigue life of aluminum alloys after the realization of impact-oscillatory loading are revealed by experiment. Firstly, it is established that the realization of dynamic non-equilibrium processes (DNP) in sheet aluminum alloys leads to the creation of dissipative structures in the volume of alloys, the density of which is less than that of the main material. As a result, the effects of microextrusions caused by less dense dissipative structures are manifested on the surface of alloys. Secondly, it is shown that the phase composition of alloys, which in addition to the solid aluminum-based solution includes the reinforcing phases in the form of dispersed Al2Cu particles (the so-called Θ-phase) and CuAl2Mg (the so-called S-phase), changes favorably in such a way that the concentration of particles of the S-phase decreases dramatically, and the concentration of particles of the Θ-phase increases.