2016 Volume 57 Issue 12 Pages 2104-2109
This study examined the delaying effect of fatigue crack growth induced by high-density electric current on A6061-T6 aluminum alloy. To investigate the effect, fatigue tests were conducted using specimens with and without electric current treatment. The fatigue life of the treated specimens increased significantly compared with untreated specimens. After the tests, the fracture surfaces were examined using scanning electron microscope. In the specimens in which electric current was applied, local melting on the crack surface was observed via fractography. To clarify the effects of electric current treatment on fatigue crack propagation, early crack growth was investigated using the plastic replication method. A delaying effect was particularly noticeable in the small-crack region. Results show that this delaying effect can be attributed to crack shielding caused by local melting on the crack surface, which signifies that the fatigue life is improved by the application of high-density electric current.