STRUCTURE OF CERAMIC SURFACES MODIFIED BY ION BEAM TECHNIQUES.

Abstract

A variety of structures are produced by ion implantation in ceramics. Random (substitutional and interstitial site occupancy) solid solutions with concentrations of solute that exceed the solubility limit can be produced in Al//2O//3. Silicon carbide becomes amorphous in a manner analogous to Si for ion fluences that produce more than 0. 2 dpa damage. Light (N) and heavy (Cr) ions produce similar results if the fluence is scaled to damage energy deposited. Because of mass differences in the ions, two damage regions are developed in TiB//2. The structure remains crystalline to high damage levels. These structural alterations cause changes in surface mechanical properties. When coupled with selective annealing, this technique has the potential for producing a range of surface structures.