The invention is a method of qualifying an implantable ceramic component made
of high-purity dense yttria tetragonal zirconium oxide polycrystal (Y-TZP) by application
of non-destructive tests. Specifically, a qualified Y-TZP ceramic component or
witness sample is examined by X-ray diffraction to determine the initial monoclinic
phase content. The component or witness sample is exposed to steam at 127
C. for a predetermined period of time, preferably six hours. The monoclinic phase
content is determined for the post-exposure sample. The absolute difference between
the initial monoclinic phase content and the post-exposure monoclinic phase content
is calculated by difference. If the difference is less than 2.1% the sample is
accepted. In an alternate embodiment, the components that pass the screening test
are examined by ultrasonic testing to evaluate soundness of the ceramic component.
Any component that presents a flaw of greater than three microns is rejected.