Abstract
The oxidation of an Fe-Cr-Al-Y-Zr alloy exposed to a Ga atmosphere at 1473 K has been investigated by an encapsulation method. A Ga/Ga2O3 mixture was placed within the quartz ampoules to establish the Ga2O and the O2 partial pressures enveloping a Fe-Cr-Al-Y-Zr alloy (specifically, 72.8Fe-22Cr-5Al-0.1Y-0.1Zr by mass pct), which contains minor additions of yttrium and zirconium to improve scale adherence. A deoxidized Ar atmosphere surrounded the ampoules to control oxygen permeation through the silica wall. The Fe-Cr-Al-Y-Zr alloy developed an Al2O3 scale growing parabolically and protecting the substrate from gallium attack for 5, 10, 20, 40, and 50 days, as examined with a scanning electron microscope (SEM) and energy dispersive X-ray (EDX) analysis. The Ga2O atmosphere decomposes to liquid Ga and Ga2O3 on the alloy surface, but gallium species do not penetrate the oxide layer according to the limits of detection for EDX analysis. Defect equilibria incorporating Ga2O are presented with neutral interstitial oxygen to explain the oxidation of the Fe-Cr-Al-Y-Zr alloy.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
