Skip to main content Accessibility help

Contribution of a New Generation Field-Emission Scanning Electron Microscope in the Understanding of a 2099 Al-Li Alloy

  • Nicolas Brodusch (a1), Michel Trudeau (a2), Pierre Michaud (a1), Lisa Rodrigue (a2), Julien Boselli (a3) and Raynald Gauvin (a1)...


Aluminum-lithium alloys are widespread in the aerospace industry. The new 2099 and 2199 alloys provide improved properties, but their microstructure and texture are not well known. This article describes how state-of-the-art field-emission scanning electron microscopy (FE-SEM) can contribute to the characterization of the 2099 aluminum-lithium alloy and metallic alloys in general. Investigations were carried out on bulk and thinned samples. Backscattered electron imaging at 3 kV and scanning transmission electron microscope imaging at 30 kV along with highly efficient microanalysis permitted correlation of experimental and expected structures. Although our results confirm previous studies, this work points out possible substitutions of Mg and Zn with Li, Al, and Cu in the T1 precipitates. Zinc and magnesium are also present in “rice grain”–shaped precipitates at the grain boundaries. The versatility of the FE-SEM is highlighted as it provides information in the macro- and microscales with relevant details. Its ability to probe the distribution of precipitates from nano- to microsizes throughout the matrix makes FE-SEM an essential technique for the characterization of metallic alloys.


Corresponding author

* Corresponding author. E-mail:


Hide All
Benoit, D., Brault, G., Bresse, J., Grillon, F., Maurice, F., Pouchou, J. & Ruste, J. (1989). Processus physiques et leur simulation par la méthode de Monte-Carlo. In Microanalyse par sonde électronique: Aspects quantitatifs, Maurice, F. (Ed.), pp. A1A38. Paris, France: ANRT.
Canovic, S., Jonsson, T. & Halvarsson, M. (2008). Grain contrast imaging in FIB and SEM. J Phys Conf Ser 126(1), 012054-1–4.
Charlot, F. & Jonnard, P. (2008). Les intéractions électrons—Matière. In Microscopie Électronique à Balayage et Microanalyses, Brisset, F. (Ed.), pp. 1362. Les Ulis Cedex A, France: EDP Sciences.
Crewe, A.V., Langmore, J.P. & Isaacson, M.S. (1975). Resolution and contrast in the STEM. In Physical Aspects of Electron Microscopy and Microbeam Analysis, Siegel, B.M. & Beaman, D.R. (Eds.), pp. 4762. New York: John Wiley & Sons.
Donnadieu, P., Shao, Y., De Geuser, F., Botton, G. A., Lazar, S., Cheynet, M., de Boissieu, M. & Deschamps, A. (2011). Atomic structure of T1 precipitates in Al-Li-Cu alloys revisited with HAADF-STEM imaging and small-angle X-ray scattering. Acta Mater 59(2), 462472.
Erdman, N., Kikuchi, N., Laudate, A. & Robertson, V. (2009). Multispectral imaging in a FEG-SEM. Adv Mater Proc 167(9), 2831.
Gauvin, R., Hovington, P. & Drouin, D. (1995). Quantification of sperical inclusions in the scanning electron microscope using Monte Carlo simulations. Scanning 17, 202219.
Gauvin, R. & Michaud, P. (2009). MC X-Ray, A new Monte Carlo program for quantitative X-ray microanalysis of real materials. Microsc Microanal 15, 488489.
Giummarra, C., Rioja, R.J., Bray, G.H., Magnusen, P.E. & Moram, J.P. (2007a). Al-Li alloys: Development of corrosion resistant, high toughness aluminium-lithium aerospace alloys. Proc ICCA 11(1), 176188.
Giummarra, C., Thomas, B. & Rioja, R.J. (2007b). New aluminum-lithium alloys for aerospace applications. In Proceedings of the Third International Conference on Light Metals Technology, September 24–26, 2007, Saint-Sauveur, Canada, Sadayappan, K. & Sahoo, M. (Eds.). Ottawa: CANMET.
Goldstein, J., Newbury, D., Joy, D., Lyman, C., Echlin, P., Lifshin, E., Sawyer, L. & Michael, J. (2003a). Generation of X-rays in the SEM specimen. In Scanning Electron Microscopy and X-Ray Microanalysis, 3rd ed., Goldstein, J., Newbury, D., Joy, D., Lyman, C., Echlin, P., Lifshin, E., Sawyer, L. & Michael, J. (Ed.), pp. 271296. New York, Boston, Dordrecht, London, Moscow: Klewer Academic/Plenum Publishers.
Goldstein, J., Newbury, D., Joy, D., Lyman, C., Echlin, P., Lifshin, E., Sawyer, L. & Michael, J. (2003b). Electron beam-specimen interactions. In Scanning Electron Microscopy and X-ray Microanalysis, 3rd ed., Goldstein, J., Newbury, D., Joy, D., Lyman, C., Echlin, P., Lifshin, E., Sawyer, L. & Michael, J. (Ed.), pp. 6198. New York, Boston, Dordrecht, London, Moscow: Klewer Academic/Plenum Publishers.
Horny, P., Lifshin, E., Campbell, H. & Gauvin, R. (2010). Development of a new quantitative X-ray microanalysis method for electron microscopy. Microsc Microanal 16(6), 821830.
Joy, D.C., Ko, Y.U. & Hwu, J. (2000). Metrics of resolution and performance for CD-SEMs. Proc SPIE 3998, 108.
Kikuchi, N., Shinzawa, T., Negishi, T., Ogura, K. & Nielsen, C.H. (2007). Observation of crystalline contrast with using low energy electrons in SEM. Microsc Microanal 13(Suppl 2), 972973.
Kim, N.J. & Lee, E.W. (1993). Effect of T1 precipitate on the anisotropy of Al-Li alloy 2090. Acta Metall Mater 41(3), 941948.
Krivanek, O.L., Chisholm, M.F., Nicolosi, V. & Pennycook, T.J. (2010). Atom-by-atom structural and chemical analysis by annular dark-field electron microscopy. Nature 464, 571574.
Leapman, R. (2004). EELS quantitative analysis. In Transmission Electron Energy Loss Spectroscopy in Materials Science and the EELS ATLAS, 2nd ed., Ahn, C.C. (Ed.), pp. 4996. Weinheim, Germany: Wiley-VCH.
Lich, B., Novak, L., Bosch, E., Stokes, D.J., Phifer, D.W. & Tuma, L. (2010). Angular backscattered filtering with an immersion lens SEM. Microsc Microanal 16(Suppl 2), 402403.
Liu, J. (2000). Contrast of highly dispersed metal nanoparticles in high-resolution secondary electron and backscattered electron images of supported metal catalysts. Microsc Microanal 6, 388399.
Ma, Y., Zhou, X., Thompson, G.E., Hashimoto, T., Thomson, P. & Fowles, M. (2011). Distribution of intermetallics in an AA 2099-T8 aluminium alloy extrusion. Mater Chem Phys 126, 4653.
Merli, P.G., Corticelli, F. & Morandi, V. (2002). Images of dopant profiles in low-energy scanning transmission electron microscopy. Appl Phys Lett 81(24), 45354537.
Merli, P.G. & Morandi, V. (2005). Low-energy STEM of multilayers and dopant profiles. Microsc Microanal 11, 97104.
Morandi, V. & Merli, P.G. (2007). Scanning electron microscopy of thinned specimens: From multilayers to biological samples. Appl Phys Lett 90, 163113-1163113-3.
Morandi, V., Merli, P.G. & Ferroni, M. (2006). Dopant regions imaging in scanning electron microscopy. J Appl Phys 99, 043512-1–7.
Munoz-Morris, M.A. & Morris, D.G. (2010). Severe platic deformation processing of Al-Cu-Li alloy for enhancing strength while maintaining ductibility. Scripta Mater 63, 304307.
Nakagawa, M., Dunne, R., Koike, H., Sato, M., Pérez-Camacho, J.J. & Kennedy, B.J. (2002). Low voltage FE-STEM for characterization of state-of-the-art silicon SRAM. J Electron Microsc 51(1), 5357.
Newbury, D.E. (1998). Trace element detection at nanometer scale spatial resolution. J Electron Microsc 47(5), 407418.
Newbury, D.E. (2006). The new X-ray mapping: X-ray spectrum imaging above 100 kHz output count rate with the silicon drift detector. Micros Microanal 12, 2635.
Newbury, D.E. (2009). The revolution in energy dispersive X-ray spectrometry: Spectrum imaging at output count rates above 1 MHz with the silicon drift detector on a scanning electron microscope. Spectroscopy 24(7), 3243.
Pennycook, S.J. (1989). Z-contrast STEM for materials science. Ultramicroscopy 30, 5869.
Pouchou, J.-L. (2004). Introduction à l'analyse EBSD: Principes Généraux et Mise en Œuvre dans un MEB. In L'analyse EBSD—Principes et applications. Pouchou, J.-L. (Ed.), pp. 124. Les Ulis Cedex A, France: EDP Sciences—GN-MEBA.
Probst, C., Gauvin, R. & Drew, R.A. (2007). Imaging of carbon nanotubes with tin-palladium particules using STEM detector in a FE-SEM. Micron 38, 402408.
Reimer, L. (1998). Emission of backscattered and secondary electrons. In Scanning Electron Microscopy, 2nd ed., Reimer, L. (Ed.), pp. 135169. Springer-Verlag.
Richards, R.J., Owen, G.R. & Gwynn, I. (1999). Low voltage backscattered electron imaging (<5 kv) using field emission scanning electron microscopy. Scan Microsc 13(1), 5560.
Rowlands, N., Holland, J. & Bhattiprolu, S. (2009). Large area SDD detectors. Adv Mater Proc 167(5), 4143.
Singh, A.K., Imam, M.A. & Sadananda, K. (1988). Artifacts introduced by ion milling in Al-Li-Cu alloys. J Electron Microsc Techniq 8, 355361.
Steigerwald, M.D., Arnold, R., Bihr, J., Drexel, V., Jaksch, H., Preikszas, D. & Vermeulen, J.P. (2004). New detection system for GEMINI. Microsc Microanal 10, 13721373.
Terauchi, M., Takahashi, H., Handa, N., Murano, T., Koike, M., Kawachi, T., Imazono, T., Koeda, M., Nagano, T., Sasai, H., Oue, Y., Yonezawa, Z. & Kuramoto, S. (2012). Ultrasoft-X-ray emission spectroscopy using a newly designed wavelength-dispersive spectrometer attached to a transmission electron microscope. J Electron Microsc 61(1), 18.
Unocic, K.A., Mills, M.J. & Daehn, G.S. (2010). Effect of gallium focused ion beam milling on preparation of aluminium thin foils. J Microsc 240(3), 227238.
Ushiki, T., Hashizume, H., Itoh, S., Kuboki, K., Saito, S. & Tanaka, K. (1998). Low-voltage backscattered electron imaging of non-coated biological samples in a low-vacuum environment using a variable-pressure scanning electron microscope with a YAG-detector. J Electron Microsc 47(4), 351354.
von Harrach, H.S., Klenov, D.O., Freitag, B., Schlossmacher, P., Collins, P.C. & Fraser, H.L. (2010). Comparison of the detection limits of EDS and EELS in S/TEM. Microsc Microanal 16, 13121313.
Wangyao, P., Zrnik, J., Kasl, J., Novy, Z. & Komolwit, P. (2003). The application of electron channelling contrast mode to study the recrystallization process in nickel alloy after different thermomechanical processing conditions. J Metals Mater Min 12(2), 5157.
Washeed, A. & Lorimer, G.W. (1997). Dispersoids in Al-Li AA8090 series alloys. J Mater Sci 32, 33413347.
Wilkinson, A.J. & Hirsch, P.B. (1997). Electron diffraction based techniques in scanning electron microscopy of bulk materials. Micron 28(4), 279308.
Woo, K.D. & Kim, S.W. (2002). The mechanical properties and precipitation behavior of an Al-Cu-Li-(In,Be) alloy. J Mater Sci 37, 411416.


Contribution of a New Generation Field-Emission Scanning Electron Microscope in the Understanding of a 2099 Al-Li Alloy

  • Nicolas Brodusch (a1), Michel Trudeau (a2), Pierre Michaud (a1), Lisa Rodrigue (a2), Julien Boselli (a3) and Raynald Gauvin (a1)...


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed