Abstract :
Hydroxyapatite ceramics for biomedical
applications are often used in form of coatings to
increase the biocompatibility of metallic implants, e.g.
the femoral shaft of a hip prosthesis. A new method to
produce such layers is electrophoretic deposition
(EPD). The aim of this study was to investigate the
influence of different powders and process parameters
on the quality of the electrophoretically deposited thin
HA layers. In order to attain layers with a thickness
less than 50 lm, it is essential to use fine powders with
particle sizes in the sub-micron range, and to stabilize
these powders in suspension. We show that commercially
available hydroxyapatite powders, which usually
have a strong tendency to agglomerate, can be milled
to particle sizes smaller than 500 nm by adding an
organic dispersant. When such milled powders are used
together with optimized process parameters, thin and
homogenous layers can be produced by EPD. Using
either aqueous or non-aqueous suspensions, hydroxyapatite
layers can be deposited directly onto a metallic
hip shaft, or onto a polymeric membrane, producing
thin free-standing ceramics used for special biomedical
applications
