Modification of the mechanical properties of ceramics by ion implantation

Abstract

The effects of ion implantation on the mechanical properties are reviewed for alumina, silicon carbide and fully-stabilized zirconia. It is demonstrated that by ion implantation, (a) hardness of the near surface layer is varied over a wide range, depending on ion dose and implantation temperature, (b) significant increases in the flexural strength are observed, (c) the resistivity against the crack initiation and propagation associated with Vickers indentation is increased, (d) the resistivity against lateral and radial crackings associated with scratching by a loaded diamond stylus is increased, (e) a reduction in the friction coefficient from 0.6 to 0.15 is observed for polycrystalline silicon carbide in sliding contact with a steel. These results are discussed in terms of microstructural changes, surface compression stress and amorphized surface layer of an increased plasticity.