Quantitative Microstructure and Defect Density Analysis of Polycrystalline Tungsten Reference Samples after Different Heat Treatments
-
A. Manhard
Abstract
In order to provide a solid basis for the correlation of microstructure and hydrogen isotope retention in tungsten, reference samples with different microstructures were prepared from a single batch of polycrystalline tungsten by standardised polishing and heat treatment procedures. Representative samples were analysed by scanning electron microscopy and scanning transmission electron microscopy as well as by electron backscatter diffraction. We show that if the annealing temperature is increased from 1 200 to 1 500 K, practically only the density of dislocations and grain boundaries with very small misorientations of less than 2° is reduced, while for annealing at 1 700 and 2 000 K, also the density of high-angle grain boundaries is reduced due to grain growth. Furthermore, the dislocation density is reduced by nearly two orders of magnitude compared to tungsten annealed at 1 200 K. We also comment on two different textures on the front and rear side of the samples that were observed both by X-ray diffraction and EBSD.
Kurzfassung
Um eine solide Basis für die Korrelation von Mikrostruktur und Wasserstoffisotop-Rückhaltung in Wolfram zu schaffen, wurden aus einer einzigen Fertigungscharge polykristallinen Wolframs durch standardisierte Polier- und Wärmebehandlungsverfahren Referenzproben mit unterschiedlichen Mikrostrukturen gefertigt. Repräsentative Proben wurden mittels Rasterelektronenmikroskopie, Rastertransmissionselektronenmikroskopie und Rückstreuelektronenbeugung analysiert. Es wird gezeigt, dass durch eine Erhöhung der Glühtemperatur von 1 200 auf 1 500 K praktisch nur die Dichte von Versetzungen und Korngrenzen mit sehr kleinen Missorientierungen von weniger als 2° reduziert wird, während beim Glühen bei 1 700 und 2 000 K aufgrund von Kornwachstum auch die Dichte der Großwinkel-Korngrenzen sinkt. Verglichen mit bei 1 200 K geglühtem Wolfram nimmt zudem auch die Versetzungsdichte um beinahe zwei Größenordnungen ab. Weiterhin werden zwei verschiedene Texturen auf der Vorder- und Rückseite der Proben besprochen, die durch Röntgenbeugung und EBSD entdeckt wurden.
References / Literatur
[1] R.Frauenfelder, Vac. Sci. Technol.6 (1) (1969) 388–397. Solution and Diffusion of Hydrogen in Tungsten 10.1116/1.1492699Suche in Google Scholar
[2] J.Roth et al., J. Nucl. Mater.390–391 (2009) 1–9. Recent Analysis of Key Plasma Wall Interactions Issues for ITER 10.1016/j.jnucmat.2009.01.037Suche in Google Scholar
[3] R.A.Causey, J. Nucl. Mater.300 (2002) 91–117. Hydrogen Isotope Retention and Recycling in Fusion Reactor Plasma-Facing Components 10.1016/S0022-3115 (01)00732-2Suche in Google Scholar
[4] A.Manhard et al., Pract. Metallography50 (1) (2013) 5–16. A Step-By-Step Analysis of the Polishing Process for Tungsten Specimens 10.3139/147.110215Suche in Google Scholar
[5] A.Manhard et al., J. Nucl. Mater415 (1S) (2011) S632–S635. Influence of the Microstructure on the Deuterium Retention in Tungsten 10.1016/j.jnucmat.2010.10.045Suche in Google Scholar
[6] M.Balden et al., J. Nucl. Mater414 (2011) 69–72. D2 gas-filled blisters on deuterium-bombarded tungsten 10.1016/j.jnucmat.2011.04.031Suche in Google Scholar
[7] M.Balden et al., J. Nucl. Mater452 (2014) 248–256. Deuterium retention and morphological modifications of the surface in five grades of tungsten after deuterium plasma exposure 10.1016/j.jnucmat.2014.05.018Suche in Google Scholar
[8] M.H.J.‘t Hoen et al., Nucl. Fusion54 (2014) 083014 (10pp). Surface morphology and deuterium retention of tungsten after low- and high-flux deuterium plasma exposure 10.1088/0029-5515/54/8/083014Suche in Google Scholar
[9] W.Espe: Werkstoffe der Hochvakuumtechnik (vol. 1), VEB Deutscher Verlag der Wissenschaften (1960)Suche in Google Scholar
[10] R.E.Reed-Hill: Physical Metallurgy Principles (2nd ed.), D. Van Nostrand Company (1973)Suche in Google Scholar
[11] A.Jablonski et al., NIST SRD64 v. 3. 2 (2010) National Institute of Standards and Technology, Gaithersburg, USASuche in Google Scholar
[12] J. M.Liu and B.-W.Shen, Acta Metall.30 (6) (1982), 1197–1202. Grain Boundary Fracture in Tungsten Bi-Crystals 10.1016/0001-6160 (82)90014-1Suche in Google Scholar
[13] S.Lindig et al., Phys.Scr.T145 (2011) 014039 (7pp). Sub-surface structures of ITER-grade W (Japan) and re-crystallized W after ITER-similar low energy 10.1088/0031-8949/2011/T145/014039Suche in Google Scholar
[14] G.K.Williamson and R.E.Smallman, Philos. Mag.1 (1) (1956) 34–46. III. Dislocation Densities in some Annealed and Cold-Worked Metals from Measurements on the X-Ray Debye-Scherrer Spectrum 10.1080/14786435608238074Suche in Google Scholar
[15] D.Raabe, B.Mülders, G.Gottstein and K.Lücke, Materials Science Forum157–162 (1994) 841–846. Textures of Cold Rolled and Annealed Tantalum 10.4028/www.scientific.net/MSF.157-162.841Suche in Google Scholar
[16] Y.B.Park, D.N.Lee and G.Gottstein, Mater.Sci. Eng.A257 (1998) 178–84. A Model of the Development of Recrystallization Textures in Body Centered Cubic Metals 10.1016/S0921-5093(98)00837-5Suche in Google Scholar
[17] Y.B.Park, D.N.Lee and G.Gottstein, Acta Mater.46 (1998) 3371–9. The Evolution of Recrystallization Textures in Body Centered Cubic Metals 10.1016/S1359-6454 (98)00052-4Suche in Google Scholar
[18] F.J.Humphtreys and MHatherly, Recrystallization and Related Annealing Phenomena, Elsevier (Amsterdam), 200410.1016/B978-008044164-1/50016-5Suche in Google Scholar
[19] D.N.Lee, Metals and Materials5 (1999) 401–17. Strain Energy Release Maximization Model for Recrystallization Textures 10.1007/BF03026153Suche in Google Scholar
[20] D.N.Lee, Inter. J. Mechanical Science42 (2000) 1645–78. Strain Energy Release Maximization Model for Evolution of Recrystallization Textures 10.1016/S0020-7403 (99)00095-8Suche in Google Scholar
[21] J.W.Pugh, Transaction of the Metallurgical Society of AIME, 212 (1958) 637–663. The Temperature Dependence of Preferred Orientation in Rolled TungstenSuche in Google Scholar
[22] J.Reiser, M.Rieth, B.Dafferner, A.Hoffmann, X.Yi and D.E.J.Armstrong, J. Nucl. Mater.424 (2012) 197–203. Tungsten Foil Laminate for Structural Divertor Applications-Analyses and Characterisation of Tungsten Foil. 10.1016/j.jnucmat.2012.02.030Suche in Google Scholar
[23] D.N.Lee, J. Mater. Processing Technol.117 (2001) 307–310. A Stability Criterion for Deformation and Deposition Textures of Metals During Annealing 10.1016/S0924-0136 (01)00787-7Suche in Google Scholar
[24] A.Manhard, PhD thesis, Augsburg University (2012). Deuterium Inventory in Tungsten after Plasma Exposure: A Microstructural Survey http://opus.bibliothek.uni-augsburg.de/opus4/frontdoor/index/index/docId/1981Suche in Google Scholar
© 2015, Carl Hanser Verlag, München
Artikel in diesem Heft
- Contents/Inhalt
- Contents
- Editorial
- Editorial
- Technical Contributions/Fachbeiträge
- The Interlamellar Spacing of Pearlite
- Quantitative Microstructure and Defect Density Analysis of Polycrystalline Tungsten Reference Samples after Different Heat Treatments
- Beware of Hot Tearing in Lifting Lugs – a Case Study in Mechanical Engineering
- Meeting Diary/Veranstaltungskalender
- Meeting Diary
Artikel in diesem Heft
- Contents/Inhalt
- Contents
- Editorial
- Editorial
- Technical Contributions/Fachbeiträge
- The Interlamellar Spacing of Pearlite
- Quantitative Microstructure and Defect Density Analysis of Polycrystalline Tungsten Reference Samples after Different Heat Treatments
- Beware of Hot Tearing in Lifting Lugs – a Case Study in Mechanical Engineering
- Meeting Diary/Veranstaltungskalender
- Meeting Diary
