Hostname: page-component-7b7567c8c-lpg2g Total loading time: 0 Render date: 2026-11-15T20:06:09.865Z Has data issue: false hasContentIssue false

Internal Friction of a High-Nb Gamma-TiAl-Based Alloy with Different Microstructures

Published online by Cambridge University Press:  26 February 2011

M. Weller
Affiliation:
Max-Planck-Institut für Metallforschung, Heisenbergstr. 3, D-70569 Stuttgart, Germany
H. Clemens
Affiliation:
Dept. of Physical Metallurgy and Materials Testing, Montanunivesität Leoben, Franz-JosefStrasse 18, A-8700 Leoben, Austria
G. Dehm
Affiliation:
Max-Planck-Institut für Metallforschung, Heisenbergstr. 3, D-70569 Stuttgart, Germany
G. Haneczok
Affiliation:
Institute of Materials Science, Silesian University, Katowice, Poland
S. Bystrzanowski
Affiliation:
Technical University of Hamburg-Harburg, Dept. of Materials Science and Technology, Eisendorferstrasse 42, D-21071 Hamburg, Germany
A. Bartels
Affiliation:
Technical University of Hamburg-Harburg, Dept. of Materials Science and Technology, Eisendorferstrasse 42, D-21071 Hamburg, Germany
R. Gerling
Affiliation:
Institut for Materials Research, GKSS Research Centre, Max-Planck-Strasse 1, D-21502 Geesthacht, Germany
E. Arzt
Affiliation:
Max-Planck-Institut für Metallforschung, Heisenbergstr. 3, D-70569 Stuttgart, Germany
Get access

Abstract

An intermetallic Ti-46Al-9Nb (at%) alloy with different microstructures (near gamma, duplex, and fully lamellar) was studied by internal friction measurements at 300 K to 1280 K using different frequency ranges: (I) 0.01 Hz to 10 Hz and (II) around 2 kHz. The loss spectra in range I show (i) a loss peak of Debye type at T ≈ 1000 K which is only present in duplex and fully lamellar samples; (ii) a high-temperature damping background above ≈ 1100 K. The activation enthalpies determined from the frequency shift are H = 2.9 eV for the loss peak and H = 4.1–4.3 eV for the high-temperature damping background. The activation enthalpies for the visco-elastic high-temperature damping background agree well with values obtained from creep experiments and are in the range of those determined for self-diffusion of Al in TiAl. These results indicate that both properties (high-temperature damping background and creep) are controlled by volume diffusion-assisted climb of dislocations. The loss peak is assigned to diffusion-controlled local glide of dislocation segments which, as indicated by transmission electron microscopy observations, are pinned at lamella interfaces.

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.)

Article purchase

Temporarily unavailable