MATERIAL AND APPLIED RESEARCHIN ŘEŽ NEUTRON PHYSICS LABORATORY

Petr Lukáš et al.Nuclear Physics Institute, 250 68 Řež

Czech Republic

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

Reactor LVR 15, NRI Řež p.l.c.Reactor LVR 15, NRI Řež p.l.c.

Neutron diffraction laboratory, NPI ŘežNeutron diffraction laboratory, NPI Řež

B ó ro v á z á c h y to v á te ra p ie

10 2 m

T K S N -4 0 0

S A N S

v íc e ú č e lo v ý d if ra k to m e tr

S P N -1 0 0n e u tro n o v o d

K S N -2

H K 9

H K 8-a

H K 8-b

H K 6

H K 3

H K 2

H K 4 p rá šk o v ýd ifra k to m e tr

Investigation of stress fields around Investigation of stress fields around weld jointsweld joints

Non destructive examination Non destructive examination of residual stresses of residual stresses by neutron diffractionby neutron diffraction

in collaboration with dr L. Mráz, Welding Research Institute, Bratislava, SK

SStresstress fields around weld joints fields around weld joints

CC SiSi MnMn P S Cr Ni Mo

0.102 - 0.76 - - 0.27 3.94 0.24

CC SiSi MnMn P S Cr Ni Mo

0.144 0.314 1.004 0.006 0.0013 0.372 0.057 0.019

VV TiTi CuCu Al Nb B N Ca

0. 47 0.015 0.016 0.0043 0.020 0.0015 0.005 0.024

Chemical composition of the WELDOX700 steel (weight %)Chemical composition of the WELDOX700 steel (weight %)

Chemical composition of the weld metal (weight %)Chemical composition of the weld metal (weight %)

10

x

300

75

150

3

z

y

2mm

2 m m

weld metal corrections

SStresstress fields around weld joints fields around weld joints

Plate 15Ch2MFA, 7 mm thicknesswelding material Inconel 52x

zy

Weld deposited passWeld deposited pass

Residual stressesResidual stresses

in FGM in FGM AlAl22OO33/Y-ZrO/Y-ZrO22 ceramics ceramics

Non destructive examination Non destructive examination of residual stresses of residual stresses by neutron diffractionby neutron diffraction

in collaboration with Prof. Van der Biest, KU Leuven, Belgium

Residual stresses in FGM AlResidual stresses in FGM Al22OO33 / Y- ZrO/ Y- ZrO22 ceramicsceramics

Task: high performance hip replacements

all-ceramic bearings

metal femoral stem

FGM FGM AlAl22OO33/Y-ZrO/Y-ZrO22 ceramicsceramics

productionproduction electrophoretic depositionelectrophoretic deposition sintering at 1350sintering at 1350ooC/1hour C/1hour hot isostatic pressing athot isostatic pressing at

13901390ooC/20 min/140MPaC/20 min/140MPa

80 90 100

0

1

2

3

4

5

dept

h/m

m

Al2O

3vol. fraction / %

alumina:alumina: low wear rate, high hardness low wear rate, high hardness

zirconia:zirconia: high strength, high toughness high strength, high toughness

medical applicationsmedical applications hip prosthesis / all ceramics bearingship prosthesis / all ceramics bearings high biocompatibilityhigh biocompatibility high performancehigh performance compressive stress at working surfacecompressive stress at working surface

Lamellar ball-head tested at the neutron diffractometer SPN100

Macroscopic residual stress in the produced ball-headMacroscopic residual stress in the produced ball-head

macroscopic residual stress scanned through the produced lamellar ball-head

0 2 4 6 8

-100

0

100

200

300

stre

ss /

MP

a

x / mm

workingsurface

Macroscopic residual stress in the produced ball-headMacroscopic residual stress in the produced ball-head

Residual stressesResidual stresses

in in highly radioactive materialshighly radioactive materials

Non destructive examination Non destructive examination of residual stresses of residual stresses by neutron diffractionby neutron diffraction

in collaboration with Dr. A. Hojná, NRI Řež, CZ

Residual stresses in highly radioactive materialsResidual stresses in highly radioactive materials

TasksTasks......

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

Dedicated shielding container Dedicated shielding container

specimen

shieldingshutter,collimator

linear stage

linear stagesteppingmotor

easy specimen installationeasy specimen installation

in the hot cellsin the hot cells

remote control of beamremote control of beam

shutters and collimatorsshutters and collimators

specimen positioningspecimen positioning

dedicated facility - shielding box, beam shutters, specimen manipulators

Residual stresses in radioactive reactor componentsResidual stresses in radioactive reactor components

In situIn situ tests tests

mechanical propertiesmechanical properties

MATERIAL ANDMATERIAL AND APPLI APPLIED RESEARCH ED RESEARCH @@ NPI NPI ŘEŽŘEŽ

~1 V, 1 5 0 0 A

neutron diffraction profileintensity phase volume fractionposition strain/stresswidth/shape microstrain

Experimental arrangementExperimental arrangement

th erm al n eu tronch a n n el

b ea m sh u tter

m on och ro m a tor sh ie ld in g

sa m p le

h or izon ta lly fo cu sin gm on och ro m a tor

d efo rm a tionm ach in e

p ositio n -sen sitived etec tor

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

In situIn situ tests @ TKSN400, tests @ TKSN400, NPI ŘNPI Řeežž

TRIP steelsTRIP steels

In situIn situ tests – mechanical properties tests – mechanical properties

in collaboration with Prof. J. Zrník, West Bohemia University, Pilsen

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

TRIP steels /transformation induced plasticity/TRIP steels /transformation induced plasticity/

1. phase: polygonal ferrite

2. phase: bainite

Ferrite-bainite (α) matrix (BCC)

Retained Austenite (γ) (FCC)

Strain-Induced Martensite (α’) (BCT)

3. phase: retained austenite

4. phase: martensite

Comparison of the stress/strain behaviours of different types of structural steels

Application of TRIP multiphase steels in automotive industry

bainite(~ 20%)

ferrite (~ 60%)

retainedaustenite (~ 20%)

TRIP steels /transformation induced plasticity/TRIP steels /transformation induced plasticity/

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

TRIP steels /transformation induced plasticity/TRIP steels /transformation induced plasticity/

austenite (γ) martensite (α’)

(γ) (α’)

intercritical annealing

bainitic holding

water quenching

TRIP steelsTRIP steels

thermomechanical treatment 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

Shape memory alloysShape memory alloys

In situIn situ tests – mechanical properties tests – mechanical properties

in collaboration with Dr. P. Šittner, IoP, Prague

Inter-phase boundary propagation

shape memory effect

Shape memory alloysShape memory alloys

dust detector

MARS Pathfinder

Applications: shape memory effectsensorsactuatorsshock absorberfittings…

superelasicitymedical tools /e.g. cathetrization, laparoscopy/high biocompatibility - stents

Shape memory alloysShape memory alloys

polycrystal, T=295K, =2%

100m

Evolution of:

stresses?

strains?

phase fractions?

in [hkl] oriented grains

2.0 2.1

Mar

tens

ite

Aus

teni

te

d -sp ac in g [A ]

A x ia l

PSD

Axia l

2d sin( )= nhkl

N eu tron b eam

Ten sile stress

Tem p era tu re

Shape memory alloysShape memory alloys

Cal. constants:

S1

111, E1

111 and E2

111

(111) austenite , axial, compression, T=336K

Cal. equations:

G=

111*S1

111=

111*73 718

G=el

G +tr

G =

111*E1

111 + (1-I

111/I

0,111)*E2

111=

111*1.597 + (1-I

111/I

0,111)*0.05

measured calculatedNo.

111 I

111/I

0,111

G

G

1 0 1 0 02 0.0016 0.99 117 .005

Evaluation of stress-strain response of NiTi from in-situ neutron diffraction data

0.00 0.01 0.02 0.030

100

200

300

400

500

600

Str

ess

, G [

MP

a]

Strain, G

calculated G-

G curve

from 111

and I111

using

constants S1

111, E1

111, E2

111

experimental G-

G curve

0.00 0.01 0.02 0.030

2

4

6

8E1

111=1.597

Latti

ce s

train

, 11

1 x

10-3

Strain, G

0.000 0.005 0.010 0.015 0.020 0.0250.5

0.6

0.7

0.8

0.9

1.0

E2

111= 0.05

Inte

ngra

l int

ensi

ty I

111/I 0,

111

Transf. strain tr

G=

G-el=

G-E

1*

111

0 100 200 300 400 500 6000

2

4

6

8

S1

111=73718 MPa

Latti

ce s

train

, 11

1 x

10-3

Stress, G [MPa]

Macroscopic stress-strain response of NiTi can be reconstructed from the in-situ diffraction data using 3 calibration constants S1, E1 E2

Ultimate goal:

Nondestructive in-situ evaluation of stress-strain responses from embedded NiTi particles in SMA composites

smart composites

SMAwires

kevlar- epoxy

Pseudoelasticity of NiTi in Pseudoelasticity of NiTi in compresioncompresion