Hostname: page-component-586b7cd67f-2plfb Total loading time: 0 Render date: 2024-11-27T01:49:10.949Z Has data issue: false hasContentIssue false

Imaging Dislocations in Duplex Tial Using Electron Channeling Contrast

Published online by Cambridge University Press:  02 July 2020

B.C. Ng
Affiliation:
Department of Materials Science and Mechanics Michigan State University, East Lansing, MI48824-1226
T.R. Bieler
Affiliation:
Department of Materials Science and Mechanics Michigan State University, East Lansing, MI48824-1226
M.A. Crimp
Affiliation:
Department of Materials Science and Mechanics Michigan State University, East Lansing, MI48824-1226
Get access

Extract

Electron channeling contrast imaging (ECCI), performed using a scanning electron microscope, has been used to observe dislocations in bulk TiAl with a duplex microstructure. The ECCI technique is based on the dependence of the back-scattered electron (BSE) yield (of the incident beam orientation) on the crystal lattice and defect orientation near the specimen surface. This allows nearsurface defects to be imaged in bulk specimens [1, 2]. ECCI was carried out in a Camscan 44FE FEG-SEM operated at 25 kV using a beam divergence of ∽8 mrad and a beam current of ∽ 2nA. Specimens were observed at a working distance of approximately 11 mm. To record the BSE signal, the microscope was fitted with an annular (four quadrant) silicon diode detector array attached to the final lens pole-piece, resulting in a solid angle collection of approximately ∽0.6 π str. Images were recorded as 32 frame averages using ∽1.1 frames/sec.

Type
Metals and Alloys
Copyright
Copyright © Microscopy Society of America

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1.Morin, P., et al., Phil. Mag. A, 40 (1979) pp. 511.CrossRefGoogle Scholar
2.Czernuska, J.T., et al., Mat. Res. Soc. Symp. Proc. Vol. 209 (1991) pp. 289.CrossRefGoogle Scholar