THE INFLUENCE OF SURFACE MODIFICATION UPON THE ANGULAR-DISTRIBUTION OF SLIP TRACES ON THE SURFACE OF POLYCRYSTALLINE FCC METALS

Surface modification by ion implantation leads to a smaller portion of grains of a polycrystalline metal showing slip traces as a result of cyclical deformation. The analysis of the azimuthal distribution of the slip traces gives an approach to explain this experience in more detail. Analytical and numerical calculation of the azimuthal distribution of slip traces under consideration of the slip geometry relative to the free surface leads to azimuthal distributions as experimentally determined for polycrystalline nickel after implantation with N+-ions and following cyclic fatigue with constant amplitude of plastic strain epsilon-pa = 10(-4).