![Page 1: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/1.jpg)
22 July 2008 1
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
Characterisation of Microstructure in model ODS Alloys
Arup Dasgupta
Physical Metallurgy DivisionIndira Gandhi Centre for Atomic Research
Kalpakkam – 603102, INDIA
A collaborative work between IGCAR, Kalpakkam and International Advanced Research Centre for Powder
Metallurgy and New Materials, Hyderabad
![Page 2: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/2.jpg)
22 July 2008 2
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
SCHEME
• The Issue– What kind of alloy is under development
– Processing Scheme
– Importance of microstructure and microchemistry investigations in alloy development
• This Talk– Types of samples studies so far
– Results and Discussion
– Summary
![Page 3: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/3.jpg)
22 July 2008 3
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
The Alloy under development
9Cr-0.12C-2W-0.2Ti-0.35Y2O3 Ferritic/Martensitic steel chosenbecause of advantages over austenitic stainless steels:
• Higher thermal conductivity
• Lower thermal expansion
• Lower void swelling during irradiation
• Excellent high temperature creep resistance
• W Mo replacement for solid solution strengthening; reduced activation
• Ti Helps to get finer dispersoids
Mandate: Clad Tubes (6.6mm OD, 0.45mm thick, 2.65 m long)
![Page 4: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/4.jpg)
22 July 2008 4
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
Processing Scheme
Courtesy: IGCAR ODS Task force, ARCI - Hyderabad
Extr. Rods Mother Tubes Clad TubesMult. Pass CWInt. Heat Trtmt.
Machining
![Page 5: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/5.jpg)
22 July 2008 5
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
Importance of Microstructural & Microchemical Investigations MA systems
• Grain morphology• Phase stability• Microstructural Uniformity • Mechanical Interdiffusion
(Microchemical Uniformity) Milling process
+
Subsequent Annealing Steps
Dispersoid Large strain fields• Shape• Size• Distribution• Interface with matrix• Dislocations, other defects
Impurities Microstr. Mech. Prop.• Microstructure / Microchemistry
Purity of feed powders, containers, milling conditions
![Page 6: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/6.jpg)
22 July 2008 6
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
Samples Studied
#ODS 0: 48h Milled Fe-0.2Ti-0.35Y2O3 Powder
#ODS 1: Fe-0.35Y2O3
Fe (150µm) and Y2O3 (1.33µm) ball milled / 30h, annealed at 973K / vacuum , double compacted, double sintered at 1323K / H2
#ODS 2: Fe-0.2Ti-0.35Y2O3
Fe (150µm), Ti (105µm) and Y2O3 (1.33µm) ball milled / 30h, annealed at 973K / vac., double compacted, double sintered at 1323K / H2
#ODS 3: Fe-0.2Ti-0.35Y2O3 - Forged
Fe (150µm), Ti (105µm) and Y2O3 (10-20nm) attritor milled / 20h, degassed at 723K & sealed. Can hipped/ forged at 1323K/ 1000MPa
#ODS 4: Fe-0.12C-9Cr-2W-0.2Ti – Pre-alloyed Powder – SEM Only
#ODS 5: Yttria Powder
#ODS 6: Fe-9Cr-2W-0.2Ti-0.35Y2O3-0.12C – Milled Powder
#ODS 7: Fe-9Cr-2W-0.2Ti-0.35Y2O3-0.12C – Extruded at 1050oCB1-ODS-S150-Z04-C46-D04-E1050-ER09
![Page 7: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/7.jpg)
22 July 2008 7
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
Samples Studied
#ODS 0: 48h Milled Fe-0.2Ti-0.35Y2O3 Powder
#ODS 1: Fe-0.35Y2O3
Fe (150µm) and Y2O3 (1.33µm) ball milled / 30h, annealed at 973K / vacuum , double compacted, double sintered at 1323K / H2
#ODS 2: Fe-0.2Ti-0.35Y2O3
Fe (150µm), Ti (105µm) and Y2O3 (1.33µm) ball milled / 30h, annealed at 973K / vac., double compacted, double sintered at 1323K / H2
#ODS 3: Fe-0.2Ti-0.35Y2O3 - Forged
Fe (150µm), Ti (105µm) and Y2O3 (10-20nm) attritor milled / 20h, degassed at 723K & sealed. Can hipped/ forged at 1323K/ 1000MPa
#ODS 4: Fe-0.12C-9Cr-2W-0.2Ti – Pre-alloyed Powder – SEM Only
#ODS 5: Yttria Powder
#ODS 6: Fe-9Cr-2W-0.2Ti-0.35Y2O3-0.12C – Milled Powder
#ODS 7: Fe-9Cr-2W-0.2Ti-0.35Y2O3-0.12C – Extruded at 1050oCB1-ODS-S150-Z04-C46-D04-E1050-ER09
![Page 8: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/8.jpg)
22 July 2008 8
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
![Page 9: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/9.jpg)
22 July 2008 9
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
3 size ranges:
(a) large, facetted (Fe-Co)
(b) 50 – 75 nm (Fe-Ti)
(c) sub-10 nm (Fe)
FeCo
Courtesy: Institute Nano-science Initiative IISc, Bangalore- Tecnai F-30
![Page 10: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/10.jpg)
22 July 2008 10
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
Samples Studied
#ODS 0: 48h Milled Fe-0.2Ti-0.35Y2O3 Powder
#ODS 1: Fe-0.35Y2O3
Fe (150µm) and Y2O3 (1.33µm) ball milled / 30h, annealed at 973K / vacuum , double compacted, double sintered at 1323K / H2
#ODS 2: Fe-0.2Ti-0.35Y2O3
Fe (150µm), Ti (105µm) and Y2O3 (1.33µm) ball milled / 30h, annealed at 973K / vac., double compacted, double sintered at 1323K / H2
#ODS 3: Fe-0.2Ti-0.35Y2O3 - Forged
Fe (150µm), Ti (105µm) and Y2O3 (10-20nm) attritor milled / 20h, degassed at 723K & sealed. Can hipped/ forged at 1323K/ 1000MPa
#ODS 4: Fe-0.12C-9Cr-2W-0.2Ti – Pre-alloyed Powder – SEM Only
#ODS 5: Yttria Powder
#ODS 6: Fe-9Cr-2W-0.2Ti-0.35Y2O3-0.12C – Milled Powder
#ODS 7: Fe-9Cr-2W-0.2Ti-0.35Y2O3-0.12C – Extruded at 1050oCB1-ODS-S150-Z04-C46-D04-E1050-ER09
![Page 11: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/11.jpg)
22 July 2008 11
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
![Page 12: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/12.jpg)
22 July 2008 12
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
Samples Studied
#ODS 0: 48h Milled Fe-0.2Ti-0.35Y2O3 Powder
#ODS 1: Fe-0.35Y2O3
Fe (150µm) and Y2O3 (1.33µm) ball milled / 30h, annealed at 973K / vacuum , double compacted, double sintered at 1323K / H2
#ODS 2: Fe-0.2Ti-0.35Y2O3
Fe (150µm), Ti (105µm) and Y2O3 (1.33µm) ball milled / 30h, annealed at 973K / vac., double compacted, double sintered at 1323K / H2
#ODS 3: Fe-0.2Ti-0.35Y2O3 - Forged
Fe (150µm), Ti (105µm) and Y2O3 (10-20nm) attritor milled / 20h, degassed at 723K & sealed. Can hipped/ forged at 1323K/ 1000MPa
#ODS 4: Fe-0.12C-9Cr-2W-0.2Ti – Pre-alloyed Powder – SEM Only
#ODS 5: Yttria Powder
#ODS 6: Fe-9Cr-2W-0.2Ti-0.35Y2O3-0.12C – Milled Powder
#ODS 7: Fe-9Cr-2W-0.2Ti-0.35Y2O3-0.12C – Extruded at 1050oCB1-ODS-S150-Z04-C46-D04-E1050-ER09
![Page 13: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/13.jpg)
22 July 2008 13
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
![Page 14: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/14.jpg)
22 July 2008 14
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
Samples Studied
#ODS 0: 48h Milled Fe-0.2Ti-0.35Y2O3 Powder
#ODS 1: Fe-0.35Y2O3
Fe (150µm) and Y2O3 (1.33µm) ball milled / 30h, annealed at 973K / vacuum , double compacted, double sintered at 1323K / H2
#ODS 2: Fe-0.2Ti-0.35Y2O3
Fe (150µm), Ti (105µm) and Y2O3 (1.33µm) ball milled / 30h, annealed at 973K / vac., double compacted, double sintered at 1323K / H2
#ODS 3: Fe-0.2Ti-0.35Y2O3 - Forged
Fe (150µm), Ti (105µm) and Y2O3 (10-20nm) attritor milled / 20h, degassed at 723K & sealed. Can hipped/ forged at 1323K/ 1000MPa
#ODS 4: Fe-0.12C-9Cr-2W-0.2Ti – Pre-alloyed Powder – SEM Only
#ODS 5: Yttria Powder
#ODS 6: Fe-9Cr-2W-0.2Ti-0.35Y2O3-0.12C – Milled Powder
#ODS 7: Fe-9Cr-2W-0.2Ti-0.35Y2O3-0.12C – Extruded at 1050oCB1-ODS-S150-Z04-C46-D04-E1050-ER09
![Page 15: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/15.jpg)
22 July 2008 15
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
Pore Size Distribution
0
20
40
60
80
100
120
140
2 4 8 MorePore dia. (mm)
Freq
uenc
y
Porosity ~ 1%
![Page 16: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/16.jpg)
22 July 2008 16
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
SADP
Selection RuleFCC : (h k l) all odd / evenBCC : h + k + l even
![Page 17: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/17.jpg)
22 July 2008 17
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
0
5
10
15
20
25
30
35
40
20 30 40 50 60 70 80
Size (nm)
Fre
qu
en
cy
DF
![Page 18: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/18.jpg)
22 July 2008 18
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
IMPURITY
![Page 19: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/19.jpg)
22 July 2008 19
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
Samples Studied
#ODS 0: 48h Milled Fe-0.2Ti-0.35Y2O3 Powder
#ODS 1: Fe-0.35Y2O3
Fe (150µm) and Y2O3 (1.33µm) ball milled / 30h, annealed at 973K / vacuum , double compacted, double sintered at 1323K / H2
#ODS 2: Fe-0.2Ti-0.35Y2O3
Fe (150µm), Ti (105µm) and Y2O3 (1.33µm) ball milled / 30h, annealed at 973K / vac., double compacted, double sintered at 1323K / H2
#ODS 3: Fe-0.2Ti-0.35Y2O3 - Forged
Fe (150µm), Ti (105µm) and Y2O3 (10-20nm) attritor milled / 20h, degassed at 723K & sealed. Can hipped/ forged at 1323K/ 1000MPa
#ODS 4: Fe-0.12C-9Cr-2W-0.2Ti – Pre-alloyed Powder – SEM Only
#ODS 5: Yttria Powder
#ODS 6: Fe-9Cr-2W-0.2Ti-0.35Y2O3-0.12C – Milled Powder
#ODS 7: Fe-9Cr-2W-0.2Ti-0.35Y2O3-0.12C – Extruded at 1050oCB1-ODS-S150-Z04-C46-D04-E1050-ER09
![Page 20: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/20.jpg)
22 July 2008 20
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
3 4 5 6 7 8 9 10
WL
FeK
FeK
CrK
CrK
Cou
nts
Energy (keV)
TiK
Element Wt. %
Ti 0.57
Cr 9.78
Fe 87.18
W 2.46
![Page 21: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/21.jpg)
22 July 2008 21
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
Samples Studied
#ODS 0: 48h Milled Fe-0.2Ti-0.35Y2O3 Powder
#ODS 1: Fe-0.35Y2O3
Fe (150µm) and Y2O3 (1.33µm) ball milled / 30h, annealed at 973K / vacuum , double compacted, double sintered at 1323K / H2
#ODS 2: Fe-0.2Ti-0.35Y2O3
Fe (150µm), Ti (105µm) and Y2O3 (1.33µm) ball milled / 30h, annealed at 973K / vac., double compacted, double sintered at 1323K / H2
#ODS 3: Fe-0.2Ti-0.35Y2O3 - Forged
Fe (150µm), Ti (105µm) and Y2O3 (10-20nm) attritor milled / 20h, degassed at 723K & sealed. Can hipped/ forged at 1323K/ 1000MPa
#ODS 4: Fe-9Cr-2W-0.2Ti – Pre-alloyed Powder – SEM Only
#ODS 5: Yttria Powder
#ODS 6: Fe-9Cr-2W-0.2Ti-0.35Y2O3-0.16C – Milled Powder
#ODS 7: Fe-9Cr-2W-0.2Ti-0.35Y2O3-0.16C – Extruded at 1050oCB1-ODS-S150-Z04-C46-D04-E1050-ER09
![Page 22: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/22.jpg)
22 July 2008 22
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
1 2 3 14 15 16 17 18 19 20
YK
OK
YK
Cou
nts
(arb
.un.
)
Energy (keV)
YL
EDS: Yttria Powder, as received
Av. Particle Size (XRD) : 42 nm
![Page 23: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/23.jpg)
22 July 2008 23
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
Samples Studied
#ODS 0: 48h Milled Fe-0.2Ti-0.35Y2O3 Powder
#ODS 1: Fe-0.35Y2O3
Fe (150µm) and Y2O3 (1.33µm) ball milled / 30h, annealed at 973K / vacuum , double compacted, double sintered at 1323K / H2
#ODS 2: Fe-0.2Ti-0.35Y2O3
Fe (150µm), Ti (105µm) and Y2O3 (1.33µm) ball milled / 30h, annealed at 973K / vac., double compacted, double sintered at 1323K / H2
#ODS 3: Fe-0.2Ti-0.35Y2O3 - Forged
Fe (150µm), Ti (105µm) and Y2O3 (10-20nm) attritor milled / 20h, degassed at 723K & sealed. Can hipped/ forged at 1323K/ 1000MPa
#ODS 4: Fe-0.12C-9Cr-2W-0.2Ti – Pre-alloyed Powder – SEM Only
#ODS 5: Yttria Powder
#ODS 6: Fe-9Cr-2W-0.2Ti-0.35Y2O3-0.12C – Milled Powder
#ODS 7: Fe-9Cr-2W-0.2Ti-0.35Y2O3-0.12C – Extruded at 1050oCB1-ODS-S150-Z04-C46-D04-E1050-ER09
![Page 24: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/24.jpg)
22 July 2008 24
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
![Page 25: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/25.jpg)
22 July 2008 25
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
Samples Studied
#ODS 0: 48h Milled Fe-0.2Ti-0.35Y2O3 Powder
#ODS 1: Fe-0.35Y2O3
Fe (150µm) and Y2O3 (1.33µm) ball milled / 30h, annealed at 973K / vacuum , double compacted, double sintered at 1323K / H2
#ODS 2: Fe-0.2Ti-0.35Y2O3
Fe (150µm), Ti (105µm) and Y2O3 (1.33µm) ball milled / 30h, annealed at 973K / vac., double compacted, double sintered at 1323K / H2
#ODS 3: Fe-0.2Ti-0.35Y2O3 - Forged
Fe (150µm), Ti (105µm) and Y2O3 (10-20nm) attritor milled / 20h, degassed at 723K & sealed. Can hipped/ forged at 1323K/ 1000MPa
#ODS 4: Fe-0.12C-9Cr-2W-0.2Ti – Pre-alloyed Powder – SEM Only
#ODS 5: Yttria Powder
#ODS 6: Fe-9Cr-2W-0.2Ti-0.35Y2O3-0.12C – Milled Powder
#ODS 7: Fe-9Cr-2W-0.2Ti-0.35Y2O3-0.12C – Extruded at 1050oCB1-ODS-S150-Z04-C46-D04-E1050-ER09
![Page 26: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/26.jpg)
22 July 2008 26
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
Pore Density ~0.3% aligned along Extrusion direction Tears
![Page 27: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/27.jpg)
22 July 2008 27
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
Y L : 0.63 %Ti K : 0.36 %Cr K : 8.95 %Fe K : 87.6 %W L : 2.44 %
![Page 28: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/28.jpg)
22 July 2008 28
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
0
![Page 29: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/29.jpg)
22 July 2008 29
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
Summary
Seven sets of model materials studied (powders, milled, compacted products)
Higher Milling Duration Agglomeration
The sintered products were porous, 14-20% but forged material had a porosity ~1%. Extruded material had porosity ~0.3% only!
Yttria bcc with a=10.6 Å
Forged sample fine bcc yttria particles with an av. size ~ 10-20 nm; some were ~ 5-7 nm and some were agglomerated; there appeared to be an orientation between the Yttria and the rextallised ferrite grains
Prealloyed powder & yttria powder desired sizes + quite pure
The extruded ODS steel desired composition, fine martensite laths (~100 nm wide) within the elongated grains, very fine (~ 3nm) yttria.
![Page 30: Characterisation of Microstructure in model ODS Alloys](https://reader033.vdocuments.us/reader033/viewer/2022051216/56815044550346895dbe435e/html5/thumbnails/30.jpg)
22 July 2008 30
Indira Gandhi Centre for Atomic Research
Kalpakkam – 603 102, India
WS&FT-08
Physical Metallurgy Division, PMD
ContributorsIGCAR, Kalpakkam ARCI, Hyderabad
Arup Dasgupta*, R Divakar, S Saroja, E Mohandas, M Vijayalakshmi, PV Sivaprasad,
KBS Rao & Baldev Raj
R Vijay, S Sudhakara Sarma, A Venugopala Reddy