Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/41655

Title

Amorphous phase formation in plasma-sprayed hydroxyapatite coatings

Author(s)

Gross, Karlis A.;  Berndt, Christopher C.;  Herman, Herbert

Abstract

The amorphous phase content of air plasma-sprayed hydroxyapatite coatings is dependent upon spraying and deposition conditions. X-ray diffraction and optical microscopy were used to investigate the influence of spray parameters on the formation of the amorphous phase. Results show three factors which most influence the formation of the amorphous phase: dehydroxylation of the molten particle during flight, the cooling rate as it impinges onto the metal substrate, and the substrate temperature. Crystalline regions were identified as unmelted particles and elongated recrystallized areas. Amorphous phase regions vary throughout the coating but are more commonly found at the coating-substrate interface, i.e., the regions decrease toward the surface of the coating. Such an inhomogeneous distribution of phase content is expected to affect the clinical process of bone deposition, and therefore successful implant fixation. The amorphous phase content of air plasma-sprayed hydroxyapatite coatings is dependent upon spraying and deposition conditions. X-ray diffraction and optical microscopy were used to investigate the influence of spray parameters on the formation of the amorphous phase. Results show three factors which most influence the formation of the amorphous phase: dehydroxylation of the molten particle during flight, the cooling rate as it impinges onto the metal substrate, and the substrate temperature. Crystalline regions were identified as unmelted particles and elongated recrystallized areas. Amorphous phase regions vary throughout the coating but are more commonly found at the coating-substrate interface, i.e., the regions decrease toward the surface of the coating. Such an inhomogeneous distribution of phase content is expected to affect the clinical process of bone deposition, and therefore successful implant fixation.

Publication type

Journal article

Source

Journal of Biomedical Materials Research, Vol. 39, no. 3 (Mar 1998), pp. 407-414

Publication year

1998

Keyword(s)

Amorphous materials;  Amorphous phases;  Biocompatible materials;  Biomaterials;  Calibration;  Ceramic coatings;  Coating microstructure;  Crystal microstructure;  Crystal structure;  Crystallization;  Dehydroxylation;  Deposition;  Heat transfer;  Hydroxyapatites;  Hydroxyapatite coatings;  Hydroxylation;  Implant;  Interfaces (materials);  Nonhuman;  Optical microscopy;  Particle Size;  Physical chemistry;  Plasma spraying;  Prosthesis;  Sprayed coatings;  Surface Properties;  Tooth implantation;  X-ray diffraction analysis

Publisher

John Wiley & Sons

ISSN

0021-9304

Publisher URL

http://dx.doi.org/10.1002/(SICI)1097-4636(19980305)39:3<407::AID-JBM9>3.0.CO;2-N

Copyright

Copyright © 1998 John Wiley & Sons, Inc. Publisher does not officially support author/institution self-archiving of either the postprint (final, revised accepted draft) or published version of full text.

Peer reviewed