TY - JOUR
T1 - Surface hardening of biomedical Ti-29Nb-13Ta-4.6Zr and Ti-6Al-4V ELI by gas nitriding
AU - Nakai, Masaaki
AU - Niinomi, Mitsuo
AU - Akahori, Toshikazu
AU - Ohtsu, Naofumi
AU - Nishimura, Hideki
AU - Toda, Hiroyuki
AU - Fukui, Hisao
AU - Ogawa, Michiharu
N1 - Funding Information:
This study was partially supported by Grant-in-Aid for Young Scientists (Start-up) from Japan Society for the Promotion of Science (JSPS) and by the Light Metal Education Foundation (Osaka, Japan). The authors would like to express their deepest thanks to Associate Professors H. Kimura and M. Oku, IMR, Tohoku University (Sendai, Japan), for microstructural evaluation by XPS and AES.
PY - 2008/7/15
Y1 - 2008/7/15
N2 - The microstructure and hardness near the surface of a biomedical titanium alloy, Ti-29Nb-13Ta-4.6Zr (TNTZ), subjected to gas nitriding at 1023-1223 K was investigated in comparison with the conventional biomedical Ti-6Al-4V ELI (Ti64). After gas nitriding, the microstructure near the specimen surface was observed by optical microscopy, X-ray diffraction (XRD), Auger electron spectroscopy (AES), and X-ray photoelectron spectroscopy (XPS). In both alloys, two types of titanium nitrides (TiN and Ti2N) are formed and the α phase is precipitated by gas nitriding. Furthermore, the oxygen impurity in the gas nitriding atmosphere reacts with the titanium nitrides; thus, TiO2 is formed at the outermost titanium nitride layer. The surface hardening was also evaluated by Vickers hardness measurement. The Vickers hardness near the surface of TNTZ and Ti64 increases significantly by gas nitriding.
AB - The microstructure and hardness near the surface of a biomedical titanium alloy, Ti-29Nb-13Ta-4.6Zr (TNTZ), subjected to gas nitriding at 1023-1223 K was investigated in comparison with the conventional biomedical Ti-6Al-4V ELI (Ti64). After gas nitriding, the microstructure near the specimen surface was observed by optical microscopy, X-ray diffraction (XRD), Auger electron spectroscopy (AES), and X-ray photoelectron spectroscopy (XPS). In both alloys, two types of titanium nitrides (TiN and Ti2N) are formed and the α phase is precipitated by gas nitriding. Furthermore, the oxygen impurity in the gas nitriding atmosphere reacts with the titanium nitrides; thus, TiO2 is formed at the outermost titanium nitride layer. The surface hardening was also evaluated by Vickers hardness measurement. The Vickers hardness near the surface of TNTZ and Ti64 increases significantly by gas nitriding.
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U2 - 10.1016/j.msea.2007.08.065
DO - 10.1016/j.msea.2007.08.065
M3 - Article
AN - SCOPUS:42949171051
SN - 0921-5093
VL - 486
SP - 193
EP - 201
JO - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
JF - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
IS - 1-2
ER -