title: Biomedical titanium alloys with Young's moduli close to that of cortical bone.
abstract: Biomedical titanium alloys with Young's moduli close to that of cortical bone, i.e., low Young's modulus titanium alloys, are receiving extensive attentions because of their potential in preventing stress shielding, which usually leads to bone resorption and poor bone remodeling, when implants made of their alloys are used. They are generally β-type titanium alloys composed of non-toxic and allergy-free elements such as Ti-29Nb-13Ta-4.6Zr referred to as TNTZ, which is highly expected to be used as a biomaterial for implants replacing failed hard tissue. Furthermore, to satisfy the demands from both patients and surgeons, i.e., a low Young's modulus of the whole implant and a high Young's modulus of the deformed part of implant, titanium alloys with changeable Young's modulus, which are also β-type titanium alloys, for instance Ti-12Cr, have been developed. In this review article, by focusing on TNTZ and Ti-12Cr, the biological and mechanical properties of the titanium alloys with low Young's modulus and changeable Young's modulus are described. In addition, the titanium alloys with shape memory and superelastic properties were briefly addressed. Surface modifications for tailoring the biological and anti-wear/corrosion performances of the alloys have also been briefly introduced.
authors.affiliation: Institute for Materials Research, Tohoku University, 2-1-1, Katahira, Aoba-Ku, Sendai 980-8577, Japan and.
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Niinomi
authors.affiliation: Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Institute for Materials Research, Tohoku University, 2-1-1, Katahira, Aoba-Ku, Sendai 980-8577, Japan and.
authors.forename: Masaki
authors.initials: M
authors.lastname: Nakai
authors.affiliation: Institute for Materials Research, Tohoku University, 2-1-1, Katahira, Aoba-Ku, Sendai 980-8577, Japan and.
authors.forename: Huihong
authors.initials: H
authors.lastname: Liu
authors.affiliation: Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Li
keywords: TNTZ; Young’s modulus; biological performances; mechanical strength; surface modification; titanium alloys