A study of the early stages of erosion of 1100 aluminum using a mechanical properties microprobe

The incubation period during erosion of 1100 Al has been studied by monitoring the changes occurring in the immediate subsurface layers using a mechanical properties microprobe. The near surface regions reach maximum hardness well before stead state, concurrent with the development of a characteristic surface ripple structure. This is interpreted as support for models of material removal based on some form of critical strain criteria rather than a fracture flow stress. It is also observed that material under valleys in the ripple structure is hardened to shallower depths. The significance of this result is not yet clear but appears to be linked to the development of the ripple structure