In recent years, the opportunity of the hard tissues such as bones, hip joints and tooth to be replaced by metallic biomaterials is increasing. In general, metallic biomaterials lack bioactivity, which is the ability to directly form a chemical bond with bones. Therefore, the bioactive surface modifications on surface of metallic biomaterials have been investigated and applied. Among them, the calcium phosphate invert glass coating method, which is dip-coating treatment (DCT), can be granted the bioactivity on the surface of β-type titanium alloy, Ti-29Nb-13Ta-4.6Zr (TNTZ) alloy, for biomaterial applications. In this study, aging characteristics and mechanical properties of TNTZ alloy surface-modified with DCT were investigated. There is an oxide layer and a case near boundary between calcium phosphate invert glass layer and TNTZ surface in TNTZ surface-modified with DCT (TNTZ DCT). A very fine ω phase precipitates in an equiaxed β phase with an average diameter of 20 μm at a distance of 200 μm from specimen surface. On the other hand, the microstructure of aged TNTZ DCT has an α phase. The tensile strength of TNTZ DCT is around 30% greater than that of as-solutionized TNTZ (TNTZ ST). On the other hand, the elongation is around 48% smaller than that of TNTZ ST. Tensile strength of aged TNTZ DCT is around 26% greater than that of TNTZ DCT. While the elongation of aged TNTZ DCT is around 52% smaller than that of TNTZ DCT. Fatigue limit of TNTZ DCT is nearly equal to that of TNTZ ST. Fatigue limit of aged TNTZ DCT is around 80 MPa greater than that of TNTZ ST. Fatigue limits of TNTZ DCT and aged TNTZ DCT, where their fatigue specimen surfaces are mirror-polished, rise as compared with those of TNTZ DCT and aged TNTZ DCT, where their fagigue specimen surfaces are shot-blasted.
|ジャーナル||Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals|
|出版ステータス||出版済み - 4 1 2006|
All Science Journal Classification (ASJC) codes