Some tests on the effect of the environment on the propagation of fatigue cracks in aluminium alloys

The investigation on the propagation of fatigue cracks in aluminium alloy sheet under fluctuating tension comprised four parts. (1) Tests to determine the combined effects of the humidity of the air and the lead frequency (clad 2024-T3 and 7075-T6). (2) Tests to determine the effect of water. (3) Tests to determine the effect of wetting with a...

Electron fractography of fatigue in vacuum

A few preliminary tests on 2024-T3 material were carried out allowing electron fractographical examination of the fracture features of fatigue crack growth in vacuum. Fatigue striations were generally not formed in vacuum: the fracture surface consists of irregular fine slip steps and coarse slip steps which show a certain periodicity. The...