Preparation of hydroxyapatite coatings from sol-gel precursors

Abstract

Since the 90s countless researches are carried out obtain a system
that combines the mechanical advantages of the metals and the biological likeness
of the hydroxyapatite ceramics. Hydroxyapatite coatings obtained via solgel
have been used with these purposes. The preliminary results of an integrated
study in which are observed diverse aspects as well as design, preparation,
characterization and evaluation of the behavior against the corrosion of
new hydroxyapatite coatings for biomedical applications are presented; on the
superalloy of MA 956 titanium of nominal composition Fe-20 Cr-5 Al-0.5 Ti-0.5
Y2O3. A thermal treatment to produce a homogeneous and compact film a-aluminium
oxide was previously applied over this superally, that acts as a barrier
against the corrosion of the metallic substrate previously treated before the Hap
coating. The hydroxyapatite layer deposited on the metallic substrate, was prepared
using a variant of the process sol-gel used by D. M. Liu in alcoholic medium
and later, crystallized by the novel technique of thermal treatment to controlled
speed. The resulting hydroxyapatite coating was characterized by means of the
reflection way of Fourier transform of
infrared spectroscopy (FTIR), x-ray diffractions
of closed angle (XRD), scanning
electronic microscopy with micro-
probe (SEM/DEX) and photo electronic
of x-ray (XPS). The analyses of
FTIR and XRD show the crystallinity
of the phase and the homogeneity in
the chemical composition of the formed
hydroxyapatite, corroborated by the
results obtained by XPS.