The influence of impurities in metal alloys and frequency of the compelled fluctuations on the evolution of fatigue damage

Abstract

The article describes theoretical studies of the influence of vibration frequency on the development of fatigue failure of metal alloys. The influence of impurities in secondary aluminum alloys on Frank Read source dislocation is shown. It was revealed that when critical stresses are reached, irreversible displacement and an increase in the number of dislocations occur, which means the beginning of the fatigue failure process. The obtained dependence made it possible to establish that the same degree of displacement of dislocations, with an increase in the frequency of forced oscillations, is achieved at high stresses. Pilot testing of theoretical calculations showed the same nature of frequency dependences of threshold stresses, fatigue strength at cycles and critical stresses. Aluminum alloys (D16 and AK9M2) were subjected to loading by alternating bending in a wide frequency range (0.3–18.0 kHz).