OXIDATION-RESISTANT GE-DOPED SILICIDE COATING ON CR-CR2NB ALLOYS BY PACK CEMENTATION

Authors
HE YR RAPP RA TORTORELLI PF
Citation
Yr. He et al., OXIDATION-RESISTANT GE-DOPED SILICIDE COATING ON CR-CR2NB ALLOYS BY PACK CEMENTATION, Materials science & engineering. A, Structural materials: properties, microstructure and processing, 222(2), 1997, pp. 109-117
Citations number
32
Categorie Soggetti
Material Science
Journal title
Materials science & engineering. A, Structural materials: properties, microstructure and processing → ACNP
ISSN journal
09215093
Volume
222
Issue
2
Year of publication
1997
Pages
109 - 117
Database
ISI
SICI code
0921-5093(1997)222:2<109:OGSCOC>2.0.ZU;2-N
Abstract
The halide-activated pack cementation process was modified to produce a Ge-doped silicide diffusion coating on Cr-Cr2Nb alloys in a single p rocessing step. The morphology and composition of the coating depended both on the pack composition and processing schedule and also on the composition and microstructure of the substrate. Higher Ge content in the pack suppressed the formation of CrSi2 and reduced the growth kine tics of the coating. Ge was not homogeneously distributed in the coati ngs. Under cyclic and isothermal oxidation conditions, the Ge-doped si licide coating protected the Cr-Nb alloys from significant oxidation a nd from pesting by the formation of a Ge-doped silica film.