Files and links (1)
PDFOpen Access (License Unspecified), Open Access
Dissertation
Development of a zirconia toughed hydroxyapatite
Doctor of Philosophy (Ph.D.), Drexel University
2000
DOI:
https://doi.org/10.17918/00009031
Abstract
Because of its low fracture toughness (<1 MPa m^(1/2)) compared to bone (2-12 MPa m^(1/2)), the use of HAp in dentistry and orthopedics is limited to low load bearing applications. In order to broaden its applications, HAp was reinforced through the addition of partially stabilized zirconia. HAp composites with varying amounts of zirconia were processed using a 2 level, 8 variable factorial design to determine the effect of various processing conditions on the stability of the zirconia and HAp phases and on the resulting toughening behavior of the composites. The processing conditions included in the design were; a) milling times and fluid dispersion mediums; b) sintering times and temperatures in ambient air and atmospheric pressure; and c) hot isostatic pressing time and temperature in inert and "wet" environments. The effect of volume fraction and particle size of the zirconia in the range of 0-30 wt % and -0.9[mu]m to -2.0[mu]m respectively on the material's fracture toughness were also determined. The composites were also placed in a serum like solution for 6 months to study the effect of physiological environment on the various processing parameters and the resulting toughening behavior. The toughening behavior before and after in vitro exposure was monitored using micro Raman spectroscopy which enabled the size and shape of the transformation zone to, be quantified. The optimization of the design parameter's resulted in an increase in the fracture toughness by a factor of three and the six month in vitro study indicated that a zirconia toughened HAp implant could be processed so as to retain its hardness and toughness in vivo.
Metrics
22 File views/ downloads
12 Record Views
Details
- Title
- Development of a zirconia toughed hydroxyapatite
- Creators
- Carie Christine Wilkinson Mager
- Contributors
- Michel W. Barsoum (Advisor) - Drexel University, Drexel University (1970-)
- Awarding Institution
- Drexel University
- Degree Awarded
- Doctor of Philosophy (Ph.D.)
- Publisher
- Drexel University; Philadelphia, Pennsylvania
- Number of pages
- xii, 153 pages
- Resource Type
- Dissertation
- Language
- English
- Academic Unit
- College of Engineering (1970-2026); Drexel University
- Other Identifier
- 991021889007504721