Fatigue deformation of 1050 aluminum in ultrasonic fatigue testing

Abstract

Ultrasonic fatigue tests have been performed on commercial 1050 aluminum. Internal friction (Q^-1) has been measured during fatigue tests and as a function of strain amplitude (ε). It is shown that more than 10⁹ cycles test is necessary in order to determine the fatigue limit. Q^-1 versus ε curves have the inflection points at particular strain amplitude which corresponds to the strain at fatigue limit. Below this strain amplitude, Q^-1 does not change and any slip bands are not observed on the specimen surface fatigued for 10¹⁰ cycles.