Measuring and testing – Testing of material
Reexamination Certificate
2006-02-14
2006-02-14
Raevis, Robert (Department: 2856)
Measuring and testing
Testing of material
Reexamination Certificate
active
06997071
ABSTRACT:
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.
REFERENCES:
patent: 4559824 (1985-12-01), Soma et al.
patent: 4722915 (1988-02-01), Soma et al.
patent: 5193540 (1993-03-01), Schulman et al.
patent: 5324316 (1994-06-01), Schulman et al.
patent: 2002/0010070 (2002-01-01), Cales et al.
patent: 2002/0031675 (2002-03-01), Cales et al.
patent: 1457470 (2004-09-01), None
patent: 2002362972 (2002-12-01), None
Jiang, Accelerated Life Testing of Y-TZP Ceramic, Proceedings of the 6th Annual Grodins Graduate Research Symposium, Biomedical Engineering Department, USC, Los Angeles, California, Mar. 23, 2002, pp. 70-71.
Jiang, In-Vitro and In-Vivo Aging Tests of BION Micro-Stimulator, Proceedings of the 7th Annual Grodins Graduate Research Symposium, Biomedical Engineering Department, USC, Los Angeles, California, Mar. 29, 2003, pp. 3-4.
Jiang, In-Vitro and In-Vivo Test of 3Y-TZP Ccramics, Oral Presentation at the 54th Pacific Coast Regional Basic Science Division Meeting of the American Ceramic Society, Seattle, Washington, Oct. 1-4, 2002, pp. 1-5.
Thompson, I. and Rawlings, R.D.; “Mechanical Behavious of Zirconia and Zirconia-Toughened Aluminia in a Simulated Body Environment”; Biomaterials; 1990; 505-508; vol. 11, Issue 7.
Drummond, J.; “In Vitro Aging of Yttria-Stablized Zirconia”; J. Am. Ceram. Soc.; 1989; 675-676; 72 [4].
Drummond, J.; “Effects of In Vitro Agina of Magnesia-Stablized Zirconia”; J. Am. Ceram. Cos.; 1992; 1278-1280; 75 [5].
Piconi, C. and Maccauro, G.; “Zirconia as a Ceramic Biomaterial”; Biomaterials; 1999; 1-25; 20.
Jiang Guangqiang
Purnell Kate E.
Schnittgrund Gary D.
Schulman Joseph H.
Alfred E. Mann Foundation for Scientific Research
Raevis Robert
Schnittgrund Gary D.
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