Study of subsurface zones induced by friction and wear using positron annihilation method

The positron annihilation studies of defect profiles in well annealed gold and copper samples whose surfaces were exposed to the friction and wear processes are presented. In the case of copper samples the defect profile was obtained by etching the layers and measuring the lineshape parameter of annihilation radiation. The defect profile detected in such a case exhibited the exponential decay dependence. For gold samples the concentration of defects in the near surface laying region were obtained using the monoenergetic positrons. Close to the surface the defect concentration is an order 10−4 and the type of the defects as positron traps did not change with the depth.