Service Communautaire d'Information sur la Recherche et le Développement - CORDIS

Establishing alumina and zirconia powders appropriate for the EPD process

The actual production process of ceramic hip joint heads ("ball heads") and cup inserts ("liners") includes spray drying and green machining. The electrophoretic deposition process (EPD) would allow the elimination of theses processes. In addition, the EPD process would allow to advantageously combining the properties of alumina and zirconia in a "functionally graded material". Alumina would act as the wear resisting outer layer, whereas zirconia would be used as a strong core material. By an appropriate combination of these materials a compression stress would be set up in the alumina surface thus increasing the load bearing capability of the component and, as a consequence, further increasing the � already high � reliability of ceramic components in total hip joint replacement.

The contribution of CeramTec was:
- the hard machining, i.e. grinding and polishing of sintered near net shape blanks of homogeneous and graded test specimens and components

Development of grinding and polishing of ball head blanks produced by EPD and by SSC process was completed successfully. Some of the ball head blanks broke during hard machining due to problems which have to be solved within the development of the EPD- and SSC-technology as well as in the design development. Ball heads which did survive the hard machining were supplied to the project partners and to the mechanical testing at CeramTec.

Reported by

CeramTec AG
Fabrikstr. 23-29
DE-73207 Plochingen
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