Nanostructured titanium-based materials for medical implants: Modeling and development Leon Mishnaevsky Jr. a, *, Evgeny Levashov b , Ruslan Z. Valiev c , Javier Segurado d , Ilchat Sabirov d , Nariman Enikeev c , Sergey Prokoshkin b , Andrey V. Solov’yov e , Andrey Korotitskiy b , Elazar Gutmanas f , Irene Gotman f , Eugen Rabkin f , Sergey Psakh’e g,h , Lude ˇk Dluhos ˇ i , Marc Seefeldt j , Alexey Smolin g,h a Technical University of Denmark, Department of Wind Energy, Risø Campus, Frederiksborgvej 399, DK-4000 Roskilde, Denmark b National University of Science and Technology ‘‘MISIS’’, Moscow 119049, Russia c Institute of Physics of Advanced Materials, Ufa State Aviation Technical University (IPAM USATU), Ufa 450000, Russia d IMDEA Materials Institute, Calle Eric Kandel 2, Getafe, 28906 Madrid, Spain e FIAS, Goethe-Universitaet Frankfurt, Ruth-Moufang-Strasse 1, 60438 Frankfurt am Main, Germany f Technion, Department of Materials Engineering, Technion City, Haifa 32000, Israel g Institute of Strength Physics and Materials Science of the Siberian Branch of the Russian Academy of Sciences (ISPMS SB RAS), Tomsk 634050, Russia h Tomsk State University (TSU), Tomsk 634050, Russia i Timplant Ltd., Sjednocenı´ 77/1, CZ72525 Ostrava, Czech Republic j KU Leuven, Departement MTM, Kasteelpark Arenberg 44, B-3001 Heverlee, Leuven, Belgium Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Titanium as a material of choice for medical implants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 3. Nanostructuring of titanium and Ti alloys: concept and technologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3.1. Nanostructuring of titanium and Ti alloys. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3.2. Severe plastic deformation: processing routes and microstructure evolution. Multiscale computational modeling . . . . . . . . . . . . . . . . 4 3.3. Novel thermomechanical ECAP processing route for fabrication of nano-Ti with very homogeneous structure and superior properties 5 3.4. Thermomechanical treatment of UFG Ti–Ni alloys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Materials Science and Engineering R 81 (2014) 1–19 A R T I C L E I N F O Article history: Available online Keywords: Ultrafine grained titanium Medical implants Computational modeling Severe plastic deformation Thermomechanical processing Nitinol A B S T R A C T Nanostructuring of titanium-based implantable devices can provide them with superior mechanical properties and enhanced biocompatibity. An overview of advanced fabrication technologies of nanostructured, high strength, biocompatible Ti and shape memory Ni–Ti alloy for medical implants is given. Computational methods of nanostructure properties simulation and various approaches to the computational, ‘‘virtual’’ testing and numerical optimization of these materials are discussed. Applications of atomistic methods, continuum micromechanics and crystal plasticity as well as analytical models to the analysis of the reserves of the improvement of materials for medical implants are demonstrated. Examples of successful development of a nanomaterial-based medical implants are presented. ß 2014 Elsevier B.V. All rights reserved. Abbreviations: ABAQUS, commercial finite element software; ARB, accumulative roll bonding; CP, crystal plasticity; DFT, density functional theory; ECAP, equal channel angular pressing; ECAP-C, equal channel angular pressing – conform; FE, finite elements; GB, grain boundary; HE, hydrostatic extrusion; HPT, high pressure torsion; GGA, generalized gradient approximation; LDA, local density approximation; MCA, movable cellular automata; MD, molecular dynamics; MLPs, martensite lattice parameters; MTLS MAX , maximum martensitic transformation; MUBINAF, multicomponent bioactive nanostructured films; NEGB, non-equilibrium grain boundary; PDA, post- deformation annealing; RSEM-RVE, representative volume element (micromechanics of materials); PIRAC, powder immersion reaction assisted coating; RRS PC , lattice strain resource recoverable strain; SEM, scanning electron microscopy; SPM, scanning probe microscopy; SPD, severe plastic deformation; TEM, transmission electron microscopy; UFG, ultra fine grained; UMAT,VUMAT, ABAQUS user subroutines; VPSC, visco-plastic self-consistent model; TJR, total joint replacements; XRD, X ray diffraction. * Corresponding author. E-mail address: lemi@dtu.dk (L. Mishnaevsky Jr.). Contents lists available at ScienceDirect Materials Science and Engineering R jou r nal h o mep ag e: w ww .elsevier .co m /loc ate/m ser http://dx.doi.org/10.1016/j.mser.2014.04.002 0927-796X/ß 2014 Elsevier B.V. All rights reserved.