Dr Maciej Krystian Scientist Austrian Institute of Technology GmbH 

High performance materials for trauma and orthopaedic applications Med-Tech Innovation Expo 2013 10 April 2013 Coventry, UK Maciej Krystiana, Bernhard Minglera, Manfred Bammera, Michael Zehetbauerb a Biomedical Systems, Health & Environment Department, AIT Austrian Institute of Technology Viktor-Kaplan-Straße 2/1, 2700 Wr. Neustadt, Austria b Physics of Nanostructured Materials, Faculty of Physics, University of Vienna Boltzmanngasse 5, 1090 Wien, Austria 

Outline  AIT Austrian Institute of Technology  Department Health & Environment  Biomedical Systems / Advanced Implant Solutions  Equal Channel Angular Pressing (ECAP)  Principle  ECAP facility at AIT Wr. Neustadt, Austria • ECAP dies  Properties of ECAP materials  Microstructure  Mechanical and biological properties  Examples of applications  Conclusions 3 10 April 2013 

Outline  AIT Austrian Institute of Technology  Department Health & Environment  Biomedical Systems / Advanced Implant Solutions  Equal Channel Angular Pressing (ECAP)  Principle  ECAP facility at AIT Wr. Neustadt, Austria • ECAP dies  Properties of ECAP materials  Microstructure  Mechanical and biological properties  Examples of applications  Conclusions 4 10 April 2013 

AIT Austrian Institute of Technology  The AIT Austrian Institute of Technology, Austria's largest non-university research institute, is among the European research institutes a specialist in the key infrastructure issues of the future.  AIT provides research and technological development to realize basic innovations for the next generation of infrastructure related technologies in the fields of health & environment, energy, mobility and safety & security. These technological research areas are supplemented by the competence in foresight & policy development. 5 10 April 2013 

AIT organisational chart 6 10 April 2013 

Department Health & Environment  Head Michaela Fritz  120 employees  4 Business Units:  Biomedical Systems  Cardiovascular Diagnostics  PET Imaging  AAL Ambient Assisted Living  Advanced Implant Solutions  Molecular Diagnostics  Bioresources  Environmental Technologies 7 10 April 2013 Employees: 33 PhD and diploma students: 14 Papers in peer reviewed journals: 50 Patents 2012 (filed + granted): 6 + 5 External contract research 2012: 1.73 M€ External grants 2012: 1.60 M€ Internal funding 2012: 2.71 M€ AIT at the location Wiener Neustadt, Austria 

Biomedical Systems certified according to ISO 13485 8 10 April 2013 

Research Field: Advanced Implant Solutions  development of new materials and process technologies (ECAP) for:  permanent implants with improved biocompatibility and tailored properties in terms of strength, ductility, fatigue, surface texture  biodegradable metals for osteosynthesis systems which are absorbed by the human body after ossification, and are also increasingly being used in cardiovascular applications. http://www.ait.ac.at/research-services/research-services-health-environment/advanced-implant-solutions/?L=1 9 10 April 2013 

Outline  AIT Austrian Institute of Technology  Department Health & Environment  Biomedical Systems / Advanced Implant Solutions  Equal Channel Angular Pressing (ECAP)  Principle  ECAP facility at AIT Wr. Neustadt, Austria • ECAP dies  Properties of ECAP materials  Microstructure  Mechanical and biological properties  Examples of applications  Conclusions 10 10 April 2013 

Severe Plastic Deformation (SPD)  SPD is the only technically viable, direct method for production of bulk, fully dense, massive (>10x10x10mm3), ultrafine grained (UFG) or even nanostructured metallic materials by means of very large plastic deformation (»1 or 100%)  The large plastic deformation during SPD is distinguished by:  multidimensional deformation under  enhanced hydrostatic pressure and  to a large extent by the preservation of the original shape of samples  The most-commonly used SPD method is the Equal Channel Angular Pressing (ECAP) technology 11 10 April 2013 

Equal Channel Angular Pressing (ECAP) – the Principle 12 10 April 2013 Schematic diagram of the ECAP process The material is multiple pressed through  a die consisting of • two channels • equal in diameter • with a set angle of intersection  under enhanced hydrostatic pressure  without changing the cross section area of the ingot. These facts enable:  processing of hard-to-deform or brittle materials (Ti, Mg)  repeated pressing with the same tool  very high deformation (~100% per pass) thus  formation of an UFG or nanostructured microstructure in  bulk, massive metallic materials 

ECAP facility at AIT Wr. Neustadt, Austria Technical specifications  dies with angle of intersection 120°, 105° and 90°  suitable for cylindrical bolts with diameters 12mm, 15mm, 20mm, 25mm and 40mm  length up to 90mm (limited by press stroke)  pressing force up to 700 kN = 70 tons  process temperature:  die set up to 500°C,  workpiece –196 °C to 900°C;  pressing speed < 20 mm/s  manual or automatic (robotized) operating modes  monitoring of all parameters 13 10 April 2013 ECAP facility at AIT Wr. Neustadt, Austria June 2011 April 2010 ECAP facility at AIT Seibersdorf, Austria August 2012 

Development of new ECAP dies sets  Dies tailored to specific materials/needs  large dimensions, strain (Mg, Al, Cu)  high strength materials (Ti alloys)  simpler design (reduction of manufacturing costs)  FEM simulations of both  ECAP dies (mainly stresses) and  workpiece (strain, microstructure, homogeneity) 14 10 April 2013 

Patents  On 29/11/2010 the AIT filed in Austrian Patent Office a patent application titled ‘A Method for Manufacturing an Article from a Metal or an Alloy, an Object Made Thereof as well as Pressing Tool Therefor’  On 10/9/2012 the AIT et al. filed in Austrian Patent Office a patent application titled ‘A Tool for Deforming a Metal Object at High Pressure’ 15 10 April 2013 

Post-processing  By post-ECAP thermo-mechanical treatment the mechanical properties of ECAP materials can be further enhanced and/or tailored (e.g. significantly higher ductility combined with still high strength)  The workpiece can be further processed by forging, isothermal forging or extrusion and shaped to (semi)finished product 16 10 April 2013 + 

Outline  AIT Austrian Institute of Technology  Department Health & Environment  Biomedical Systems / Advanced Implant Solutions  Equal Channel Angular Pressing (ECAP)  Principle  ECAP facility at AIT Wr. Neustadt, Austria • ECAP dies  Properties of ECAP materials  Microstructure  Mechanical and biological properties  Examples of applications  Conclusions 17 10 April 2013 

Grain refinement by ECAP  Change of the microstructure of commercially pure titanium by ECAP  Initial grain size of 50 μm (left, optical microscopy) and nano-sized structure after ECAP with mean grain size below 500 nm (right, optical microscopy and TEM in insert) 18 10 April 2013  Commercially Pure Titanium (CP-Ti) AIT Austrian Institute of Technology GmbH 

Grain refinement by ECAP 19 10 April 2013 Electron BackScatter Diffraction (EBSD) CEST Center of Electrochemical Surface Technology on behalf of AIT Austrian Institute of Technology GmbH (2011) Microstructure  Change of the microstructure with an average α-grain size of ~10 μm in as received material down to UFG structure with grain size of about 100nm As received ECAP  Ti 6Al-4V Extra Low Interstitials (Ti64 ELI) 

Phase shift 20 10 April 2013 Electron BackScatter Diffraction (EBSD) CEST Center of Electrochemical Surface Technology on behalf of AIT Austrian Institute of Technology GmbH (2011) Microstructure  Change in the / phase ratio  93(2) : 7(2) as received  82(2) : 18(2) after ECAP As received ECAP  Ti 6Al-4V Extra Low Interstitials (Ti64 ELI) phase  phase  phase 

Modification of grain boundaries by ECAP 21 10 April 2013 Electron BackScatter Diffraction (EBSD) CEST Center of Electrochemical Surface Technology on behalf of AIT Austrian Institute of Technology GmbH (2011) Microstructure  Significant shift from Low Angle Grain Boundaries (LAGB) towards High Angle Grain Boundaries (HAGB) As received ECAP  Ti 6Al-4V Extra Low Interstitials (Ti64 ELI) Grain boundary Grain size distribution Misorientation angle <5°(subgrains) 5–15°(LAGB) >15°(HAGB) 

Increase of mechanical properties of Ti64 ELI 22 1) As-received certificate + measurements AIT Austrian Institute of Technology GmbH, University of Vienna Yield Strength (YS) Ultimate Tensile Strength (UTS) Total strain A5 

Increase of mechanical properties of Ti64 ELI 23 1) As-received certificate + measurements AIT Austrian Institute of Technology GmbH , University of Vienna 2) AIT Austrian Institute of Technology GmbH, University of Vienna Yield Strength (YS) Ultimate Tensile Strength (UTS) Total strain A5 

Increase of mechanical properties of Ti64 ELI 24 1) As-received certificate + measurements AIT Austrian Institute of Technology GmbH University of Vienna 2) AIT Austrian Institute of Technology GmbH, University of Vienna 3) AIT Austrian Institute of Technology GmbH + Kühr GmbH Yield Strength (YS) Ultimate Tensile Strength (UTS) Total strain A5 

Increase of mechanical properties of Ti64 ELI 25 1) As-received certificate + measurements AIT Austrian Institute of Technology GmbH, University of Vienna 2) AIT Austrian Institute of Technology GmbH, University of Vienna 3) AIT Austrian Institute of Technology GmbH + Kühr GmbH Yield Strength (YS) Ultimate Tensile Strength (UTS) Total strain A5  By conventional deformation:  modest increase in strength  dramatic reduction of ductility 

Increase of mechanical properties of Ti64 ELI 26 1) As-received certificate + measurements AIT Austrian Institute of Technology GmbH, University of Vienna 2) AIT Austrian Institute of Technology GmbH, University of Vienna 3) AIT Austrian Institute of Technology GmbH + Kühr GmbH 4) Semenova et al. Mat Sci Forum 503-504 (2006) 757-762 Yield Strength (YS) Ultimate Tensile Strength (UTS) Total strain A5 

Increase of mechanical properties of Ti64 ELI 27 1) As-received certificate + measurements AIT Austrian Institute of Technology GmbH, University of Vienna 2) AIT Austrian Institute of Technology GmbH, University of Vienna 3) AIT Austrian Institute of Technology GmbH + Kühr GmbH 4) Semenova et al. Mat Sci Forum 503-504 (2006) 757-762 Yield Strength (YS) Ultimate Tensile Strength (UTS) Total strain A5  By ECAP:  Significant increase in strength (+up to 40%)  Still high ductility (=>10%) 

Increase of mechanical properties of Ti64 ELI 28 1) As-received certificate + measurements AIT Austrian Institute of Technology GmbH, University of Vienna 2) AIT Austrian Institute of Technology GmbH, University of Vienna 3) AIT Austrian Institute of Technology GmbH + Kühr GmbH 4) Semenova et al. Mat Sci Forum 503-504 (2006) 757-762 Yield Strength (YS) Ultimate Tensile Strength (UTS) Total strain A5  By post-deformation:  Shaping to (semi)finished product  Further increase in strength and ductility 

Increase of mechanical properties of Ti64 ELI 29 1) As-received certificate + measurements AIT Austrian Institute of Technology GmbH, University of Vienna 2) AIT Austrian Institute of Technology GmbH, University of Vienna 3) AIT Austrian Institute of Technology GmbH + Kühr GmbH 4) Semenova et al. Mat Sci Forum 503-504 (2006) 757-762 Yield Strength (YS) Ultimate Tensile Strength (UTS) Total strain A5 

Increase of mechanical properties of a Mg alloy 30 10 April 2013 AIT Austrian Institute of Technology GmbH Microhardness [HV] 

Increase of mechanical properties of pure Cu 31 10 April 2013 AIT Austrian Institute of Technology GmbH + Kühr GmbH Macrohardness [HV30 ] 

 Fine microstructure of Ti64 after ECAP is the basis for superplasticity at low temperatures and high strain rates  Tensile-test specimen before (top) and after a tensile test at 650°C at strain rate 1x10-3 s-1 (bottom)  Deformation of > 800% without fracture! Low-temperature superplasticity 32 AIT Austrian Institute of Technology GmbH 

Fatigue properties of pure Ti and Ti64 ELI after ECAP  Both CP-Ti and Ti64 ELI after ECAP show enhanced fatigue limit stress and durability compared to conventional materials CG: Coarse Grained UFG: UltraFine Grained after ECAP 33 L.R.Saitova et al. Mat. Sci. Eng. A 503 (2009) 145 

Biological properties of ECAP Ti64 ELI  Cell vitality on the surface of ECAP processed Ti64 ELI (right) is significantly higher compared to as-received material (left)  Vital staining of L929 cells after 24 hour incubation 34 10 April 2013 as-received ECAP BMP – Labor für Medizinische Materialprüfung GmbH on behalf of AIT Austrian Institute of Technology GmbH (2010) Cell vitality on surface of ECAP Ti64 ELI 

Biological properties of ECAP Ti64 ELI  Investigations of  hemocompatibility  adhesion of thrombocytes  thrombin generation  complement activation  haemolysis  mitochondria activity  show no significant difference between the as-received and ECAP-processed Ti64  Neither aluminum nor vanadium ions could be evidenced in aqueous extractions of ECAP Ti64 ELI 35 10 April 2013 Mitochondria activity after 24 hour incubation of both ECAP as well as as- received materials is on the level of the negative control BMP – Labor für Medizinische Materialprüfung GmbH on behalf of AIT Austrian Institute of Technology GmbH (2010) No difference in the cell number between as-received, ECAP materials and reference 

Future applications of ECAP materials in medical engineering 36  Implants made of ECAP titanium  Biodegradable magnesium stents 

37 Further examples of application of ECAP nanomaterials  Aerospace  Motorsports  Energy (hydrogen) storage  other fields 

Outline  AIT Austrian Institute of Technology  Department Health & Environment  Biomedical Systems / Advanced Implant Solutions  Equal Channel Angular Pressing (ECAP)  Principle  ECAP facility at AIT Wr. Neustadt, Austria • ECAP dies  Properties of ECAP materials  Microstructure  Mechanical and biological properties  Examples of applications  Conclusions 38 10 April 2013 

Conclusions  Equal Channel Angular Pressing (ECAP)  has demonstrated its capability of processing bulk materials (pure metals as well as alloys)  The extremely high plastic deformation leads to change of the grain size from about several ten of micrometers down to a few hundred nanometers and thus to formation of UFG microstructure  The modification of the microstructure results in • enhanced mechanical and improved biological properties comprising in particular of – superior strength (yield YS and ultimate tensile strength UTS) – higher ductility/formability (compared to conventionally processed materials) – advanced low cycle and high cycle fatigue properties – higher hardness – significant enhancement of biocompatibility, wettability, cell attachment and spreading as well as viability of ECAP surface 39 10 April 2013 

Acknowledgement  ‘Technologietransfer und Optimierung des Equal- Channel-Angular-Pressing-Verfahrens (ECAP) für Serienproduktion – SerienECAP’ (project number 830817) COIN Programme Line Cooperation and Networks by The Austrian Research Promotion Agency (FFG)  ‘BioCompatible Materials and Applications – BCMA’ initiated by the AIT Austrian Institute of Technology GmbH. It was partly funded by AIT as well as by the federal state of Lower Austria and co-financed by the E.C. (EFRE) 40 10 April 2013  This research was accomplished within the context of the following projects 

AIT Austrian Institute of Technology your ingenious partner Maciej Krystian AIT Austrian Institute of Technology GmbH Health & Environment Department Biomedical Systems Viktor-Kaplan-Straße 2/1, 2700 Wr. Neustadt, Austria T: +43(0) 50550-4849 F: +43(0) 50550-4840 [email protected] http://www.ait.ac.at