Tracer diffusion of boron in alpha-Ti and gamma-TiAl
Journal article, 2008
Tracer diffusion of boron in pure alpha-Ti and gamma-TiAl (54 at.% A]) was measured by secondary ion mass spectroscopy using the stable B-11 isotope. The diffusion coefficients follow Arrhenius temperature dependencies with the frequency factors D-0 = 4.2 x 10(-6) and 2.48 x 10(-5) m(2) s(-1) and the activation enthalpies Q = 113 and 200 kJ mol(-1) for B diffusion in polycrystalline alpha-Ti and gamma-TiAl, respectively. Boron is a fast diffuser in both Ti and TiAl. The ratio of boron and titanium diffusivities is as large as 10(6)-10(7) in alpha-Ti and amounts to 10(3)-10(4) in gamma-TiAl. These results indicate a diffusion mechanism involving interstitial jumps. The relatively high activation enthalpy of B diffusion in gamma-TiAl is explained by the structure of the octahedral sites in the intermetallic compound.
behavior
self-diffusion
al
titanium
zr
based on TiAl
defects : point defects
single-crystal
alloys
microstructure
solute diffusion
titanium aluminides
diffusion
barrier
Author
S. Divinski
University of Münster
F. Hisker
University of Münster
T. Wilger
University of Münster
Milan Friesel
Chalmers, Applied Physics
C. Herzig
University of Münster
Intermetallics
0966-9795 (ISSN)
Vol. 16 2 148-155Subject Categories (SSIF 2011)
Condensed Matter Physics
DOI
10.1016/j.intermet.2007.08.008