MATERIAL AND APPLI ED RESEARCH IN ŘEŽ NEUTRON PHYSICS LABORATORY

1. MATERIAL AND APPLIED RESEARCHIN ŘEŽ NEUTRON PHYSICS LABORATORY Petr Lukáš et al. Nuclear Physics Institute, 250 68 Řež Czech Republic

2. Reactor LVR 15, NRI Řež p.l.c. reactor power 10 MW thermal flux in the core 1.5 1018 ns-1m-2 beam tube 1 1013 ns-1m-2 fuel enrichment 36% 235U tank type light water moderated and cooled

3. Neutron diffraction laboratory, NPI Řež

4. Non destructive examination of residual stresses by neutron diffraction Investigation of stress fields around weld joints in collaboration with dr L. Mráz, Welding Research Institute, Bratislava, SK

5. Stress fields around weld joints Chemical composition of the WELDOX700 steel (weight %) Chemical composition of the weld metal (weight %)

6. Stress fields around weld joints weld metal corrections

7. Weld deposited pass Plate 15Ch2MFA, 7 mm thickness welding material Inconel 52

8. Non destructive examination of residual stresses by neutron diffraction Residual stresses in FGM Al2O3/Y-ZrO2ceramics in collaboration with Prof. Van der Biest, KU Leuven, Belgium

9. Residual stresses in FGM Al2O3/ Y- ZrO2ceramics Task: high performance hip replacements all-ceramic bearings metal femoral stem

10. FGM Al2O3/Y-ZrO2ceramics • alumina: low wear rate, high hardness • zirconia: high strength, high toughness • medical applications • hip prosthesis / all ceramics bearings • high biocompatibility • high performance • compressive stress at working surface production • electrophoretic deposition • sintering at 1350oC/1hour • hot isostatic pressing at 1390oC/20 min/140MPa

11. Macroscopic residual stress in the produced ball-head Lamellar ball-head tested at the neutron diffractometer SPN100

12. Macroscopic residual stress in the produced ball-head macroscopic residual stress scanned through the produced lamellar ball-head

13. Non destructive examination of residual stresses by neutron diffraction Residual stresses in highly radioactive materials in collaboration with Dr. A. Hojná, NRI Řež, CZ

14. Residual stresses in highly radioactive materials • Tasks... • characterization of reactor construction materials • radiation damage - material degradation during service • monitoring of residual stress level with operation time and neutron fluence • component integrity assessment, support of operation prolongation

15. Dedicated shielding container • easy specimen installation in the hot cells • remote control of beam shutters and collimators • specimen positioning

16. Residual stresses in radioactive reactor components dedicated facility - shielding box, beam shutters, specimen manipulators

17. MATERIAL AND APPLIED RESEARCH @ NPI ŘEŽ In situ tests mechanical properties

18. Experimental arrangement neutron diffraction profile intensity phase volume fraction position strain/stress width/shape microstrain

19. In situ tests @ TKSN400, NPI Řež • Deformation rig • tensile/compressive tests • maximum loading ±20 kN • Multiphase materials • shape memory alloys • transforming steels • hot air heating system 25C-300oC • el. current heating up to 1000o C

20. In situ tests – mechanical properties TRIP steels in collaboration with Prof. J. Zrník, West Bohemia University, Pilsen

21. TRIP steels /transformation induced plasticity/ Task: construction materials with well balanced strength and ductility/toughness Solution: multiphase materials duplex steels bake hardening steels interstitial free steels Transformation Induced Plasticity (TRIP) steels Twinning Induced Plasticity (TWIP) steels

22. TRIP steels /transformation induced plasticity/ ferrite(~ 60%) bainite (~ 20%) retained austenite (~ 20%) Comparison of the stress/strain behaviours of different types of structural steels 1. phase: polygonal ferrite 2. phase: bainite Ferrite-bainite (α) matrix (BCC) 3. phase: retained austenite Retained Austenite (γ) (FCC) 4. phase: martensite Strain-Induced Martensite (α’) (BCT) Application of TRIP multiphase steels in automotive industry

23. TRIP steels /transformation induced plasticity/ austenite (γ) martensite (α’) (γ) (α’) • increased plasticity due to phase transformation austenite martensite taking place in deformed steels simultaneously with dislocation plasticity • significant austenite volume fraction necessary • special concept of alloying combined with appropriate thermomechanical treatment

24. TRIP steels thermomechanical treatment intercritical annealing Chemical composition (wt.%) Mn 1.45 Si 1.9 C 0.19 Cr 0.07 P 0.02 S 0.02 Ni 0.02 Al 0.02 Nb 0.003 bainitic holding water quenching

25. In situ tests – mechanical properties Shape memory alloys in collaboration with Dr. P. Šittner, IoP, Prague

26. Shape memory alloys shape memory effect Inter-phase boundary propagation

27. Shape memory alloys dust detector MARS Pathfinder Applications: shape memory effect sensors actuators shock absorber fittings… superelasicity medical tools /e.g. cathetrization, laparoscopy/ high biocompatibility - stents

28. Shape memory alloys polycrystal, T=295K, e =2% Evolution of: stresses? strains? phase fractions? in [hkl] oriented grains 100mm

29. Pseudoelasticity of NiTi in compresion Macroscopic stress-strain response of NiTi can be reconstructed from the in-situ diffraction data using 3 calibration constants S1, E1 E2 smart composites kevlar - epoxy SMA wires Ultimate goal: Nondestructive in-situ evaluation of stress-strain responses from embedded NiTi particles in SMA composites