Optical Grain Size Measurements: What is Being Measured? Comparative Study of Optical and EBSD Grain Sizes Determination in 2D Al Foil

Abstract:

Article Preview

Reflected light optical analysis and Electron Backscatter Diffraction (EBSD) analysis have been used to m easure grain sizes in 2D Al foil samples, annealed for different times. There are significant differences in the results of the two techniques. It is shown that in Al it is possible to detect boundaries in optical images down to a misorientation angle of 7-8º. Nevertheless, in most samples the critical angle of easy etching lies above 10º. The observed differences in grain size measurements between optical analysis and EBSD analysis can be largely attributed to three phenomena: (1) individual samples may behave slighty differently due to differences in the effectiveness of etching (2) the grain size is heterogeneous over large areas and (3) the effect of etching is not only a function of misorientation angle but also grain boundary plane. Despite these uncertainties, optical analysis seems to be reliable for analysis of processes in which mainly grain boundaries with misorientation angle of > 10º are involved i.e. grain growth.

Info:

Periodical:

Materials Science Forum (Volumes 495-497)

Edited by:

Paul Van Houtte and Leo Kestens

Pages:

213-218

DOI:

10.4028/www.scientific.net/MSF.495-497.213

Citation:

S. Piazolo et al., "Optical Grain Size Measurements: What is Being Measured? Comparative Study of Optical and EBSD Grain Sizes Determination in 2D Al Foil ", Materials Science Forum, Vols. 495-497, pp. 213-218, 2005

Online since:

September 2005

Export:

Price:

$35.00

[1] V.E. Fradkov, A.S. Kravchenko, and L.S. Shvindlerman: Scripta Met. Vol. 19 (1985), p.1291.

[2] V. Sursaeva, S. Protasova, W. Lojkovskii and J. Jun: Texture and Microstructure Vol. 32 (1999) p.175.

[3] F. J. Humphreys: Journal of Micosopy Vol. 21 (2004) p.247.

[4] D.J. Prior, A.P. Boyle, F. Brenker, M.C. Cheadle, A. Day, G. Lopez, L. Peruzzo, G.J. Potts, S. Reddy, R. Spiess, N.E. Timms, P. Trimby, J. Wheeler, L. Zetterstrom: Am. Mineralogist Vol. 84, (1999), p.1741.

DOI: 10.2138/am-1999-11-1204

[5] P.W. Trimby, D.J. Prior and J. Wheeler: Journal of Structural Geology Vol. 20 (1998), p.913.

[6] V. Randle and H. Davies: Ultramicroscopy Vol. 90 (2002), p.153.

[7] J. Wheeler, D.J. Prior, Z. Jiang, R. Spiess & P.W. Trimby, 2001: Contr. Min. and Petr. Vol. 141 (2001), pg. 109.

In order to see related information, you need to Login.