SHORT DESCRIPTION OF THE DRAWINGS
The invention will be explained below by referring to the attached drawings.
FIG. 1 shows a device for carrying out the method according to the invention.
FIGS. 2 to 4 show scanning electron microscopical photos of embodiments of the hydroxylapatite metal composite material according to the invention.
FIG. 5 shows X-ray diffraction diagrams of the embodiments represented in FIGS. 2 to 4.
FIG. 6 shows infrared absorption spectra of the embodiments represented in FIGS. 2 to 4.
DETAILED DESCRIPTION OF THE INVENTION AND BEST WAY FOR CARRYING OUR THE INVENTION
The device 1 shown in FIG. 1 has been used in order to produce the hydroxylapatite metal composite materials according to the invention. The device is a high pressure/high temperature cell. This device 1 consists of two plungers 2 between which the boron nitride pressure transmitters 3 are placed. The device has a graphite heating 4 as well as a CaCo3 container 5. The mixture 6 of hydroxylapatite powder and metal powder is brought into the device 1 between the plungers 2 and the boron nitride pressure transmitters 3. The predetermined pressure is exerted by the plungers 2 onto the mixture.
EXAMPLE 1
(a) Production of a Hydroxylapatite Metal Mixture
Hydroxylapatite powder (Plasma Biotal Limited, UK) with a mean particle size of 5,30 μm and titanium powder with a mean particle size of 28,90 μm have been mixed together. the mixture has then been put in hexane and the whole mixture has been mixed thoroughfully during 30 minutes in a pot mill. The thus obtained mixture has been dried in vacuum by using a dryer at 110° C. in order to remove the hexane remaining in the mixture.
(b) Production of a Green Compact
The mixture obtained in step (a) has been brought into a pressure machine and pressed to a green compact under a pressure of 20 MPa and vacuum.
(c) Sintering
The green compact obtained in step (b) has been sintered in the high pressure/high temperature cell at a pressure of 2,5 GPa at 900° C. during 2 minutes.
FIG. 2 shows a scanning electron microscopical photo of the thus obtained hydroxylapatite titanium composite material, whereby the hydroxylapatite phase appears white while the titanium phase appears black. The three-dimensional network structure of the composite material is clearly to be recognized on this photo which causes an improvement of the tension and pressure stability of the hydroxylapatite titanium composite material compared to the materials known until now. The X-ray diffraction diagram (in FIG. 5 designated as HA/Ti) and the infrared absorption spectrum (FIG. 6 designated as HA/Ti) show that the hydroxylapatite titanium composite material does not disintegrate during the production. The volume ratio of the hydroxylapatite to the titanium in the composite material was 1:1.
EXAMPLE 2
The procedure described in example 1 has been repeated with the difference that gold which had a mean particle size of 28,9 μm has been used instead of titanium and that the sintering has been carried out in step (c) at a temperature of 700° C. The volume ratio of the hydroxylapatite to gold in the composite material was 1:1.
FIG. 3 shows a scanning electron microscopical photo of the thus obtained hydroxylapatite gold composite material, whereby the hydroxylapatite phase appears white while the titanium phase appears black. The three-dimensional network structure of the composite material is clearly to be recognized on this photo which causes an improvement of the tension and pressure stability of the hydroxylapatite gold composite material compared to the materials known until now. The X-ray diffraction diagram (in FIG. 5 designated as HA/Au) and the infrared absorption spectrum (FIG. 6 designated as HA/Au) show that the hydroxylapatite gold composite material does not disintegrate during the production.
EXAMPLE 3
The procedure described in example 1 has been repeated with the difference that silver which had a mean particle size of 10,00 μm has been used instead of titanium and that the sintering has been carried out in step (c) at a temperature of 800° C. The volume ratio of the hydroxylapatite to silver in the composite material was 1:1.
FIG. 4 shows a scanning electron microscopical photo of the thus obtained hydroxylapatite silver composite material, whereby the hydroxylapatite phase appears white while the titanium phase appears black. The three-dimensional network structure of the composite material is clearly to be recognized on this photo which causes an improvement of the tension and pressure stability of the hydroxylapatite silver composite material compared to the materials known until now. The X-ray diffraction diagram (in FIG. 5 designated as HA/Ag) and the infrared absorption spectrum (FIG. 6 designated as HA/Ag) show that the hydroxylapatite silver composite material does not disintegrate during the production.
Patent Application
20080015100
