ISSN:
1573-4889
Keywords:
chromia layer
;
alien cation diffusion
;
lattice diffusion
;
grain-boundary diffusion
;
external spinel or sulfide growth
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Diffusion of the cations Cr, Fe, Mn, and Ni in Cr2O3 has been investigated at 1173 K. The diffusion measurements were performed on chromia layers grown on the model alloys Fe-20Cr and Fe-20Cr-12Ni in order to consider effects of small amounts of dissolved alien cations in Cr2O3. The samples were diffusion annealed in H2-H2O at an oxygen partial pressure close to the Cr2O3/Cr equilibrium. For all tracers the lattice-diffusion coefficients are 3–5 orders of magnitude smaller than the grain-boundary diffusion coefficients. The lattice diffusivity of Mn is about two orders of magnitude greater than the other lattice-diffusion coefficients, especially in Cr2O3 grown on Fe-20Cr-12Ni. The values of the diffusion coefficients for Cr, Fe, and Ni are in the same range. Diffusion of the tracers in Cr2O3 grown on different alloys did not show significant differences with the exception of Mn.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00665632
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