Dip-Coating
of
Calcium Phosphate Bioceramics
onto
Titanium Alloy or Stainless Steel Strips
Bora Mavis
and A. Cuneyt Tas
Dept. of Metallurgical and
* B. Mavis
and A. C. Tas,
"Dip-Coating of Calcium Hydroxyapatite on
Titanium Alloy (Ti-6Al-4V) Substrates," Journal of The American Ceramic
Society, 83, 989-991 (2000). (----> download: dip-ha.pdf)
* B. Mavis and A. C. Tas,
"Dip-Coating of Calcium Hydroxyapatite on
Titanium Alloy (Ti-6Al-4V) and Stainless Steel (316L) Substrates,"
"Mineralization in Natural and Synthetic Biomaterials," Materials
Research Society Proceedings, Vol. 599, pp. 67-72, (Eds.) P. Li, P. Calvert, T.
Kokubo, R. Levy, and C. Scheid,
2000, USA, ISBN 1-55899-507-2.
* B. Mavis and A. C. Tas,
"Dip-Coating of Calcium Hydroxyapatite Bioceramics on Stainless Steel Strips," 100th Annual
Meeting of the American Ceramic Society, May 3-8, 1998, Cincinnati, Ohio, USA, Oral
Presentation.
* B. Mavis, "Dip-Coating of Titanium Alloy
(Ti-6Al-4V) or Stainless Steel (316L) Surfaces by Calcium Hydroxyapatite
(HA)," M.Sc. Thesis, METU, January
1999 (Thesis Supervisor: Dr. A. Cuneyt Tas).
* Patent Pending, Turkish Patent
Institute,
Abstract
Bioceramic-coated
metallic prostheses and implants were shown to display increased levels of
biocompatibility
when placed in the body environment, and these
thin coatings were also shown to impede the corrosion and
undesired metal ion transfers from the implant
itself. Calcium hydroxyapatite (HA: Ca10(PO4)6(OH)2)
is the
biomaterial of choice in such coating
applications.
HA powders
synthesized in our laboratory were used to prepare the viscous suspensions in
the spin-coating trials
onto titanium (Ti-6Al-4V) or stainless steel
(316L) strips of dimensions, 25 x 10 x 1 mm.
An
electronically-controlled “belt-and-pulley”-type
dipping apparatus, which was designed and built in our
laboratory, was used to immerse and then withdraw
the strips (25 x 10 x 1 mm) at the constant rates of 10 to 20
mm/s from the HA-containing organic slurries.
Dip-coating slurries were prepared by ultrasonification
of HA powders
mixed with appropriate amounts of natural bone
gelatin, glycerol, and polyethylene glycol. Coated strips were then heated in
the temperature range of 700 to 840°C in
flowing nitrogen atmospheres.
Sample
characterization was performed by SEM (scanning electron microscopy), XRD
(X-ray diffraction), and
EDXS (energy-dispersive X-ray spectroscopy).
Figures:
Fig. 1: Side view of dip-coated
Ti6Al4V coupon
Fig. 2: View of the coat layer after
calcinations at 800C
