title: Deformation-induced ω phase in modified Ti-29Nb-13Ta-4.6Zr alloy by Cr addition.
abstract: For spinal-fixation applications, implants should have a high Young's modulus to reduce springback during operations, though a low Young's modulus is required to prevent stress shielding for patients after surgeries. In the present study, Ti-29Nb-13Ta-4.6Zr alloy (TNTZ) with a low Young's modulus was modified by adding Cr to obtain a higher deformation-induced Young's modulus in order to satisfy these contradictory requirements. Two newly designed alloys, TNTZ-8Ti-2Cr and TNTZ-16Ti-4Cr, possess more stable β phases than TNTZ. These alloys consist of single β phases and exhibit relatively low Young's moduli of <65GPa after solution treatment. However, after cold rolling, they exhibit higher Young's moduli owing to a deformation-induced ω-phase transformation. These modified TNTZ alloys show significantly less springback than the original TNTZ alloy based on tensile and bending loading-unloading tests. Thus, the Cr-added TNTZ alloys are beneficial for spinal-fixation applications.
authors.affiliation: Department of Biomaterials Science, Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Niinomi
authors.forename: Junko
authors.initials: J
authors.lastname: Hieda
authors.forename: Masaaki
authors.initials: M
authors.lastname: Nakai
authors.forename: Ken
authors.initials: K
authors.lastname: Cho
mesh_terms: D000497:Alloys / Q000737:chemistry; D001672:Biocompatible Materials / Q000737:chemistry*; D002857:Chromium / Q000737:chemistry*; D055119:Elastic Modulus; D006244:Hardness; D008422:Materials Testing; D009556:Niobium / Q000737:chemistry*; D013314:Stress, Mechanical; D013635:Tantalum / Q000737:chemistry*; D013718:Tensile Strength; D014025:Titanium / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry*
chemical_list: D000497:Alloys; D001672:Biocompatible Materials; D009556:Niobium; D002857:Chromium; D013635:Tantalum; D015040:Zirconium; D014025:Titanium