Status of Material R&D Activities Relevant for Fusion Power Reactors
Rajamannar Swamy*1, Alpesh Patel1, Shailesh Kanpara1, S. Khirwadkar1, Kedar Bhope1,
Mayur Mehta1, Sejal Shah2, P.N. Maya1, P. Sharma2, C. S. Sasmal1, P. Chaudhuri1
1Institute for Plasma Research, Bhat, Gandhinagar, Gujarat, 382428, India2ITER-India, Institute for Plasma Research, Gandhinagar, Gujarat, 382428, India
E-mail: [email protected]
Institute for Plasma Research (IPR)
P13
Material Development for Blanket and Divertor
GLEEBLE 3800 System
Type of heating system Direct resistance with closed-loop
control
Temperature range 30°C to 2300°C
Maximum heating rate 10,000°C/sec
Maximum force 196 kN (Compression), 98 kN (Tension)Sample
Graphite
plunger
TC
[1] Tungsten-Fiber Reinforced Tungsten Composites
Optical images of Wf/W cross section (a) parallel
(b) perpendicular to the pressing direction
(a) (b)
Micromechanical model of RDSM
• The maximum relative density achieved is 96% for Vf: 70% sample
• The avg. hardness of fibers in composites is 485 ±9 HV0.4 for Vf: 70%
To improve fracture toughness and crack propagation
Radiation Damage Studies
Neutron spectra for ITER-like divertor
•W foil of 100 µm thick
• 80 MeV Au7+, 10 MeVB3+
• 1.3 x1018 ions/m2
TEM micrographs
1 100 10000E
PKA (keV)
10-4
10-3
10-2
10-1
100
101
102
103
PK
A/p
arti
cle
10 MeV Li10 MeV B80 MeV W2.3 MeV Cu20 MeV W6 MeV Feneutron
EFragment
[4] India specific Reduced Activation Ferritic
Martensitic (IN-RAFM) Steel for Breeding
Blanket Module
[1] Radiation damage in Tungsten Foils [2] Radiation damage in Insulator
•Alumina
•300 keV Ar6+ (range ~ 180nm)
•Fluence: 5x1011 to 1x1016 ions/cm2
•DPA ~3×10-4 for lowest fluence
To investigate the ion irradiation impact on the structural and electrical properties of alumina
Ref: Sunil kumar et.al. Ceramics International 45 (2019) 20346-20353Ref: P.N.Maya et.al. Nucl.Fusion 59 (2019) 076034 (14pp)
[5] Lithium Titanate (Li2TiO3)
W-fiber
Ф: 0.25-0.1mm, L: 3-5mm
W-Powder
Size: 0.5-1µm
Powder Metallurgy Route
Temperature (ºC) 1900
Pressure (MPa) 40
Holding time (min.) 4
%Vf 10, 30, 50, 70
Powder Metallurgy Route
Temperature (ºC) 1000 & 1030
Pressure (MPa) 5, 20, 40
Holding time (min.) 10
Cu (Wt. %) 20, 30, 50
High Temperature Bonding
Temperature (ºC) 1100 -1500
Pressure (MPa) 60
Holding time (min.) 15
Diffusion Bonding
To improve toughness, creep and tensile strength at high
temperature with lower shift DBTT after irradiation
Vacuum Induction Melting & Vacuum Arc Refining
Hot working
Forging Temperature (ºC) 1140 -1600
Rolling Temperature (ºC) 1100-1120
Heat Treatment
Normalizing (ºC) for 30min 980-1000
Tempering (ºC) for 90min 760-765
9Cr–1.4W–0.06Ta–0.22V-0.1C
Ф:10mm, t:4mm
To investigate the neutron induced radiation damage and its effect in fuel retention in divertor armor material using surrogate ion irradiation
80 MeV Au produces
vacancy clusters
10 MeV B irradiated
produces dislocations
Clusters
Clusters
Dislocation
To develop materials and to assess its performance under reactor-relevant conditions such as high heat and particle loads, radiation and tritium environment
0.85-1.18
mm
Dried Powder
Un
der
/ov
er
Siz
e
Pebble Fabrication
Calcined at 1000°C,5 hr.
Ball mill grinded for 6 hr.
Li2CO3
Isopropanol
TiO2
Sintered at 1100°C, 5hr
Grinding
Green Pebble
15mm Ф, 6mm to 2.5mm (t)
Surface morphology of Pebbles
prepared by FGM
100 µm 10 µm
10 µm 2 µm
Li2T
iO
3P
ow
de
r P
re
pa
ratio
nP
eb
ble
Fa
bric
atio
n
ESM FGM
Au-ion produces defects
structures at room
temperature similar to
those produced by neutron
at high temperature.• Raman and XRD analysis show defect density increased by irradiation for lower fluence whereas
defect annealing observed at higher fluence.
• Insulation resistance is observed to be changed in presence of radiation environment.
Peak intensity variation with
irradiation fluence (XRD Analysis)RAMAN Spectroscopy
PKA spectrum of ions and neutrons
B-ion produced PKA
spectrum similar to
neutron
• Li2TiO3 powder is synthesis by solid state reaction method &
solution combustion method.
• Pebbles of ~ 1.00 mm is fabricated by Extrusion-
Spheronization (ESM) & Freeze Granulation-freeze drying
method (FGM).
Li2TiO3 is developed as a Tritium Breeder Material for the
Fusion Blanket
Database generation of physical, thermal, thermo-physical,
Mechanical properties of Li2TiO3 are being evaluated
Ref: A. Shrivastava et.al. Fusion Sci. Tech. 65 (2014) 319-324
Evaluation of Material properties
• Variation of volume fraction
• Variation of fiber aspect ratio
Martensitic structure
Coarse
Cr rich carbides
V, Ta rich carbides
Fine GlobularTempered
Mechanical & Thermo-physical properties ,i.e. Thermal
diffusivity, Thermal Conductivity and Specific Heat of
commercial grade IN-RAFM steel w.r.t variation of temperature
are being evaluated
Optical image of W-laminate sample
Applications of ceramic in ITER NBIs
[3] Tungsten Laminates
100 µm thick W foils
B- scanC- scan
Ultrasonic Testing (UT), microstructure characterization and electrical
resistivity measurement show flaw less (defect free) and good interfacial
bonding of laminates
UT inspection result
To improve toughness and lower DBTT
100XRef: A.N.Mistry et.al. FED. 125 (2017) 263-268
[2] Tungsten–Copper Functionally Graded Materials
FGM Density
(a) 80/20 Grade – 6 layers – 94.5 %
(b) 70/30 Grade – 4 layers – 89.6 %
(c) 50/50 Grade – 3 layers – 88.8%
W-Powder: 0.5 - 1µm
Cu-Powder: 20-25µm
To improve chemical and thermo-mechanical compatibility at W-Cu interface
(a) SEM image (b) Elemental mapping of W/Cu FGM 70/30 grade
Microstructure characterization, thermal conductivity
measurement and mechanical properties evaluation
show good interface bonding with thermo-mechanical
compatibility of developed FGM
Layer-1 Layer-2
Layer-3 Layer-4
(a)
(b)
30 mm x 10 mm x 3mm
