AVS 51st International Symposium
    Biomaterial Interfaces Monday Sessions
       Session BI-MoP

Paper BI-MoP35
In-situ Formation of Bioactive-Titanium Coating using Reactive Plasma Spraying

Monday, November 15, 2004, 5:00 pm, Room Exhibit Hall B

Session: Poster Session
Presenter: M. Inagaki, National Institute of Advanced Industrial Science and Technology (AIST), Japan
Authors: M. Inagaki, National Institute of Advanced Industrial Science and Technology (AIST), Japan
Y. Yokogawa, National Institute of Advanced Industrial Science and Technology (AIST), Japan
T. Kameyama, National Institute of Advanced Industrial Science and Technology (AIST), Japan
Correspondent: Click to Email
A surface modification technique using reactive plasma spraying (RPS) was studied to form bioactive-titanium (Ti) coating. An in-situ surface-modification of Ti particles is conducted by making use of plasma-enhanced reactions between the Ti particles and the reactive gaseous species in the plasma flame during plasma spraying. Surface-modified Ti coatings were deposited on Ti substrates by radio-frequency (rf)-RPS using a thermal plasma of Ar gas containing 1-6% N@sub 2@ and/or 1-6% O@sub 2@ at an input power of 16 kW. As a means of surface modification, Ti powders impregnated with 0.05-0.2 mol% Ca were also sprayed. Compositional changes in the coatings' surface after soaking in simulated body fluid (SBF) were examined by Fourier transform infrared spectroscopy (FT-IR) and thin film X-ray diffraction (TF-XRD). The Ti coatings prepared with Ar-O@sub 2@ and Ar-N@sub 2@-O@sub 2@ plasma formed apatite after 3 days of soaking in SBF. This indicated that such coatings have the ability to form a biologically active bone-like apatite layer on their surface. In the TF-XRD patterns for the Ti coatings sprayed with oxygen-containing plasma, minute peaks ascribable to TiO@sub 2@ (anatase and rutile phase) were commonly observed. On the other hand, no compositional change was observed in the surface of the Ti coatings sprayed with Ar-N@sub 2@ plasma, even after 7 days of soaking in SBF. In SBF tests, we observed a retardation of apatite deposition for the Ca-added Ti coatings prepared with Ar-O@sub 2@ and Ar-N@sub 2@-O@sub 2@ plasmas. Analyses by X-ray photoelectron spectroscopy indicated that the Ca impregnated in the RPS-Ti coatings formed a Ca-O compound.