Fracture toughness, strength and slow crack growth in a ceria stabilized zirconia-alumina nanocomposite for medical applications.
Mechanical properties and slow crack growth (SCG) behavior of a 10Ce-TZP/Al2O3 nanocomposite currently developed as a biomaterial are considered. Fracture toughness is determined for sharp, long (double torsion) and short (indentation) cracks and a good agreement is found between the two types of cracks. The main toughening mechanism in the nanocomposite is the tetragonal to monoclinic phase transformation of the ceria-stabilized zirconia (Ce-TZP) phase. Transformation at the surface of ground specimens leads to surface compressive induced stresses and an increase in strength. Crack velocity curves (V-K(I) curves) are obtained under static and cyclic fatigue using the double torsion method. The static V-K(I) curve in air reveals the three stages characteristic of stress corrosion with a threshold K(I0) approximately 4.5 MPa m(1/2) and a fracture toughness of 8.8 MPa m(1/2) significantly higher than those of currently used inert bioceramics (i.e., alumina and Y-TZP). A crack growth accelerating effect is shown under cyclic loading, correlated with a decrease in the threshold. However, the cyclic fatigue threshold (4 MPa m(1/2)) still stands above that of current biomedical grade alumina and zirconia.
Benzaid
Rajaa
R
Université de Lyon, INSA-Lyon, MATEIS, CNRS UMR 5510, 20 Avenue Albert Einstein, Batiment Blaise Pascal, 69621 Villeurbanne, Cedex, France; LERSIM, Ecole Mohammadia d'Ingénieurs BP 765, Agdal Rabat, Morocco.
Chevalier
Jerome
J
Université de Lyon, INSA-Lyon, MATEIS, CNRS UMR 5510, 20 Avenue Albert Einstein, Batiment Blaise Pascal, 69621 Villeurbanne, Cedex, France.
Saâdaoui
Malika
M
LERSIM, Ecole Mohammadia d'Ingénieurs BP 765, Agdal Rabat, Morocco.
Fantozzi
Gilbert
G
Université de Lyon, INSA-Lyon, MATEIS, CNRS UMR 5510, 20 Avenue Albert Einstein, Batiment Blaise Pascal, 69621 Villeurbanne, Cedex, France.
Nawa
Masahiro
M
Advanced Technologies Development Laboratory, Matsushita Electric Works, Ltd, 1048 Kadoma, Osaka 571, Japan.
Diaz
Luis Antonio
LA
Nanomaterials and Nanotechnology Research Center, CINN-CSIC, Francisco Pintado Fe 26, 33011 Oviedo, Spain.
Torrecillas
Ramon
R
Nanomaterials and Nanotechnology Research Center, CINN-CSIC, Francisco Pintado Fe 26, 33011 Oviedo, Spain.
D000535:Aluminum / Q000737:chemistry*; D001672:Biocompatible Materials; D002563:Cerium / Q000737:chemistry*; D008422:Materials Testing; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D053761:Nanocomposites; D015040:Zirconium / Q000737:chemistry*
D001672:Biocompatible Materials; D002563:Cerium; D015040:Zirconium; D000535:Aluminum