Tue-TFI-23 Coating of Ti-6Al-4Valloywithpure titanium film by sputter

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					Tue-TFI-23: Coating of Ti-6Al-4V alloy with pure titanium film by sputter-deposition for improving
                                        biocompatibility

                    T. Sonoda,1 T. Saito,1 A. Watazu,1 K. Katou,1 T. Yamda,1 and T. Asahina1
                        1
                            National Institute of Advanced Industrial cience and Technology(AIST)
        Ti-6Al-4V alloy attracting attention as a biomaterial features excellent mechanical properties and corrosion re-
     sistance, and super plasticity, so enables the forming of denture bases of complicated shapes. However, this alloy
     contains aluminum and vanadium liable to do serious harm to human bodies, so actual use will require prevention
     of direct contact with biological tissues. On the other hand, pure titanium has been utilized as biomaterials in den-
     tal or orthopedic field, and its prostheses or implants exhibit excellent biocompatibility. In this study, therefore,
     in order to improve the biocompatibility of Ti-6Al-4V alloy, coating of the alloy substrates with pure titanium
     films by magnetron DC sputtering in Ar gas was examined, because the pure titanium barrier layer prevents such
     harmful substances from leaching out to biological tissues. Furthermore the effects of the pure titanium barrier
     layer on the cytocompatibility of the titanium alloy were investigated. Under visual observation, the obtained
     pure titanium film appeared to be uniform and adhesive. Under SEM, the surface of the deposited pure titanium
     film was observed to consist of fine particles accumulating and aggregating. According to AES in-depth profiles
     of Ti and Al for the deposited titanium film and Ti-6Al-4V alloy substrate, it was confirmed that no aluminum
     atoms diffused to the film surface from the alloy substrate. Based on the results of the in-vitro cytotoxicity test,
     it was found that the viability, i.e., the ratio of the number of living cells to the sum of the number of living cells
     and that of dead cells was higher for the titanium film than for the alloy. Therefore the deposited pure titanium
     film exhibited better cytocompatibility than the Ti-6Al-4V alloy, concluding that the biocompatibility of the alloy
     was improved by coating with the pure titanium film.

				
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posted:6/6/2010
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