Orientation Dependence of Pitting and Blistering in Proton-Irradiated Aluminum Crystals

Pitting and blistering occurred on the surfaces of aluminum crystals bombarded with protons in the 10–100 keV energy range. The extent of pitting and/or blistering was found to be orientation dependent. Surfaces with orientations near {111} were least affected. This was followed by the {100} orientation. {110} and higher indices orientations suffered greatest damage. Blistering is caused by the protons trapped as hydrogen gas, and the orientation dependence of the process is explained by the orientation dependence of penetration of ions in the aluminum lattice.