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Slow crack growth behaviour of hydroxyapatite ceramics
- Source :
- Biomaterials, Biomaterials, Elsevier, 2005, pp.6106-6112
- Publication Year :
- 2005
- Publisher :
- Elsevier BV, 2005.
-
Abstract
- Among materials for medical applications, hydroxyapatite is one of the best candidates in orthopedics, since it exhibits a composition similar to the mineral part of bone. Double torsion technique was here performed to investigate slow crack growth behaviour of dense hydroxyapatite materials. Crack rate, V , versus stress intensity factor, K I , laws were obtained for different environments and processing conditions. Stress assisted corrosion by water molecules in oxide ceramics is generally responsible for slow crack growth. The different propagation stages obtained here could be analyzed in relation to this process. The presence of a threshold defining a safety range of use was also observed. Hydroxyapatite ceramics appear to be very sensitive to slow crack growth, crack propagation occurring even at very low K I . This can be explained by the fact that they contain hydroxyl groups (HAP: Ca 10 (PO 4 ) 6 (OH) 2 ), favouring water adsorption on the crack surface and thus a strong decrease of surface energy in the presence of water. This study demonstrates that processing conditions must be carefully controlled, specially sintering temperature, which plays a key role on V–K I laws. Sintering at 50 °C above or below the optimal temperature, for example, may shift the V–K I law towards very low stress intensity factors. The influence of ageing is finally discussed.
- Subjects :
- Ceramics
Materials science
Surface Properties
Biophysics
Sintering
Biocompatible Materials
Bioengineering
02 engineering and technology
[SPI.MAT] Engineering Sciences [physics]/Materials
010402 general chemistry
01 natural sciences
[SPI.MAT]Engineering Sciences [physics]/Materials
Corrosion
Biomaterials
Crack closure
Fracture toughness
Adsorption
Tensile Strength
Materials Testing
Forensic engineering
Composite material
Stress intensity factor
Temperature
Fracture mechanics
021001 nanoscience & nanotechnology
Elasticity
Surface energy
0104 chemical sciences
Durapatite
Mechanics of Materials
Ceramics and Composites
Stress, Mechanical
Crystallization
0210 nano-technology
Subjects
Details
- ISSN :
- 01429612
- Volume :
- 26
- Database :
- OpenAIRE
- Journal :
- Biomaterials
- Accession number :
- edsair.doi.dedup.....93a51c181944f0a1a91d5a1ab4c9ebd5