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.
solute diffusion
diffusion
based on TiAl
zr
alloys
behavior
barrier
titanium aluminides
al
self-diffusion
titanium
single-crystal
microstructure
defects : point defects
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
Condensed Matter Physics
DOI
10.1016/j.intermet.2007.08.008