Indentation analysis of sub-surface deformation in ductile materials aftersolid particle erosion

Sub-surface deformation of several industrially important Ni, Co, and Fe-ba sed wrought alloys and pure Cu, Ta, and Ni was analyzed. All samples were e roded by hard Al2O3 particles at a 90 degrees impact angle and 40 m s(-1). The deformation and load-displacement response within the plastically defor med zone below the eroded surface were measured by using a nanoindentation test system. Results from the indentation test were used to determine the e ffect of materials hardness on the restitution coefficient and to compare t he amount of energy that is transferred into plastic deformation during par ticle impact. All materials showed a load-unload hysteresis, which represen ts a measure of the amount of energy dissipated into plastic deformation du ring indentation. Also, elastic recovery of the indenter was significantly higher near the eroded surface than away from the eroded surface. For all m aterials, a logarithmic-type relationship was observed between hardness and restitution coefficient. (C) 2000 Elsevier Science S.A. All rights reserve d.