A defects evolution below the surface in nickel aluminum bronze CuAl9Ni4Fe4 subjected
to cavitation under mild conditions with times up to 8h was studied using positron annihilation spectroscopy, mass loss measurements, and scanning electron and atomic force microscopies. The obtained results indicate two different stages of cavitation erosion. At the beginning of cavitation up to 6h in incubation period a removing of residual roughness and surface oxides was noted. Then, in the maximal erosion rate region, big vacancy clusters were recognized and its concentration drastically increase around 100 times in comparison with incubation period.
