Photo- and electro-stimulated probes have been employed for quantitatively evaluating
highly graded residual stress fields generated at the surface of alumina hip joints. Optical
calibrations revealed large differences in probe size, which strongly affected the detected magnitude
of residual stress. A comparison between the responses of Raman and fluorescence probes in
polycrystalline alumina showed that the depth of those probes spread to an extent in the order of the
tens of microns even with using a confocal probe configuration. On the other hand, the
electro-stimulated luminescence emitted by oxygen vacancy sites (F+ center) in the alumina lattice
represented a suitable choice for confining to a shallow volume the stress probe. The electron probe
enabled confining the measurement depth to the order of the tens of nanometers. Maps of surface
residual stress were collected on both main-wear and non-wear zones of an alumina femoral head.
A comparison among stress maps taken at exactly the same location, but employing different
probes, clarified the averaging probe effects on surface stress magnitude.
Study of an F center in molten KCl
