Kinetics of nanodefect formation on the surface of mechanically loaded metals

Scanning tunneling microscopy was used to study nanodefect formation-on the surface of Au, Cu, Mo, and Pd foils mechanically loaded at room temperatur e. It as found that loading gives rise to the formation of nanodefects in t he form of triangular prisms, with faces parallel to-slip planes. The defec t size grows with time, reaches a maximum, and then decreases, and a fracti on of the defects disappear. Instead, new, larger sized defects are formed; their concentration also passes through a maximum, and:they, in turn, give way to larger sized defects. This cycle is repeated several times over the loading time. According to their lifetime, the defects can be divided into two groups-"quasi-stationary" defects, whose: depth is a multiple of the c ritical value H-0, and "nonstationary" defects. The lifetime of quasi-stati onary defects is 3-5 orders of magnitude longer than that of nonstationary defects.