title: Fatigue characteristics of bioactive glass-ceramic-coated Ti-29Nb-13Ta-4.6Zr for biomedical application.
abstract: A new surface-coating method by which CaP invert glass is used to improve the bioactivity of titanium alloys has been developed recently. In this method, the powder of CaP invert glass (CaO-P2O5-TiO2-Na2O) is coated on the surface of titanium alloy samples and heated between 1073 and 1123 K. With this treatment, a calcium phosphate layer mainly containing beta-Ca3(PO4)2 phase can be coated easily on titanium alloy samples. In the present study, the effect of this coating process on the fatigue properties of Ti-29Nb-13Ta-4.6Zr, a new metastable beta alloy for biomedical applications, has been investigated. The fatigue endurance limit of the coated alloy was found to be about 15% higher than that of uncoated alloy, as a result of the formation of a hard (alpha + beta) layer and a small amount of the omega phase during the coating process. The coating exhibits excellent adhesion to the substrate during the tensile and fatigue tests. Subsequent ageing at 673 K for 259.2 ks greatly improves the fatigue resistance of the coated alloy due to isothermal omega phase precipitation, and does not have obvious detrimental effect on the coating properties.
authors.affiliation: Department of Production Systems Engineering, Toyohashi University of Technology, 1-1, Hibarigaoka, Tempaku-cho, Toyohashi 441-8580, Japan.
authors.forename: S J
authors.initials: SJ
authors.lastname: Li
authors.forename: M
authors.initials: M
authors.lastname: Niinomi
authors.forename: T
authors.initials: T
authors.lastname: Akahori
authors.forename: T
authors.initials: T
authors.lastname: Kasuga
authors.forename: R
authors.initials: R
authors.lastname: Yang
authors.forename: Y L
authors.initials: YL
authors.lastname: Hao
mesh_terms: D000268:Adhesiveness; D000327:Adsorption; D020811:Biomedical Technology / Q000379:methods; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D019245:Compressive Strength; D008422:Materials Testing; D009556:Niobium / Q000737:chemistry*; D019736:Prostheses and Implants; D013499:Surface Properties; D013635:Tantalum / Q000737:chemistry*; D013718:Tensile Strength; D014025:Titanium / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry*
chemical_list: D020099:Coated Materials, Biocompatible; C481486:Ti-29Nb-13Ta-4.6Zr alloy; C492648:cap invert glass; D009556:Niobium; D013635:Tantalum; D015040:Zirconium; D014025:Titanium