| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 805583 | Theoretical and Applied Mechanics Letters | 2012 | 28997 Pages |
Fatigue properties of age-hardened Al alloy 2017-T4 under ultrasonic loading frequency (20 kHz) were investigated and compared with the results under conventional loading of rotating bending (50 Hz). The growth of a crack retarded at about 500 µm in surface length under ultrasonic loading, while at about 20 µm under rotating bending. Although striations being a typical fracture mechanism were observed under conventional loading, most of fracture surface was covered with many facets under ultrasonic loading. These facets were also observed under rotating bending in nitrogen gas. The difference in growth mechanism depending on the loading frequency and the retardation of a crack growth under ultrasonic loading may be caused by the environment at the crack tip due to high crack growth rate under ultrasonic loading.
