Biomedical Engineering Reference
In-Depth Information
Fig. 9.11
Survival probability (Weibull plot) of a pure alumina disc and an FGM disc with the con-
centration profile (
top left
); micrographs illustrating the distribution of zirconia (
light grey spots
);
the biaxial strength (
bottom left
). By courtesy of Prof. J. Vleugels
100.00
95.00
90.00
85.00
80.00
A
B
B
75.00
70.00
A
0
2
4
6
Distance (mm)
Fig. 9.12
Composition profile of an acetabular cup insert: volume %Al
2
O
3
vs. distance. Courtesy
Prof. J. Vleugels
produced by hard-on-hard bearings, when there is a breakdown of fluid film lubri-
cation, provide more energy to the system than can be dissipated in the usual way.
Under the right conditions the metallic parts (titanium backing of the cup) amplify
this vibratory driving force into an audible event.
The text in italics is copied from a
paper by Walter and colleagues [
295
]. Resonance of the titanium shells and femoral
