Direct experimental evidence of the reduction of Cr2O3 by Zr at high temperature

Cr coatings are widely considered as one of most promising candidates for accident tolerant fuel (ATF). One key degradation process of Cr coating is the reduction of Cr2O3 by Zr. However, there is still a lack of direct experimental evidence for this reaction. To analyze the reaction between Cr2O3 and Zry4, they were first bonded under high temperature. After bonding, a new Cr-enriching layer adjacent to Zry4 substrate was observed, which was thought to be the direct experimental evidence for the reduction of Cr2O3. There are also another two important processes, the transformation of ZrO2 into alpha-Zr(O) and Cr/Zr inter-diffusion.