title: Strength enhancement of a biomedical titanium alloy through a modified accumulative roll bonding technique.
abstract: The strength of a biomedical β-type alloy, Ti-25Nb-3Zr-3Mo-2Sn, was enhanced through severe plastic deformation using a modified accumulative roll bonding technique. Incremental strength increases were observed after each cycle, while ductility initially fell but showed some recovery with further cycles. After 4 cycles there was a 70% improvement in the ultimate tensile strength to 1220 MPa, a two-fold increase in the 0.5% proof stress to 946 MPa and the ductility was 4.5%. The microstructure comprised of ultrafine grain β grains heavily elongated in the rolling direction with a fine dispersion of nanocrystalline α phase precipitates on the β grain boundaries. Shear bands formed in order to accommodate large plastic strains during processing and the grains within the bands were significantly finer than the surrounding matrix.
authors.affiliation: CAST CRC, School of Mechanical and Mining Engineering, The University of Queensland, Brisbane QLD 4072, Australia. d.kent@uq.edu.au
authors.forename: Damon
authors.initials: D
authors.lastname: Kent
authors.forename: Gui
authors.initials: G
authors.lastname: Wang
authors.forename: Zhentao
authors.initials: Z
authors.lastname: Yu
authors.forename: Xiqun
authors.initials: X
authors.lastname: Ma
authors.forename: Matthew
authors.initials: M
authors.lastname: Dargusch
mesh_terms: D000497:Alloys / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry*; D008422:Materials Testing; D055595:Mechanical Phenomena; D046529:Microscopy, Electron, Transmission; D013314:Stress, Mechanical; D014025:Titanium / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D000497:Alloys; D001672:Biocompatible Materials; D014025:Titanium