ZrO2-doped YTaO4 as potential CMAS-resistant materials for thermal barrier coatings application

In this contribution, the ZrO2-doped YTaO4 (ZrxY0.5-x/2Ta0.5-x/2O2 (x = 0, 0.1, 0.2, 0.28)) are proposed as potential CMAS-resistant materials for TBCs. The corrosion behavior of those materials under CMAS attack are investigated from thermodynamics and kinetics. The results show that all compositions have the much better CMAS resistance than the classical Gd2Zr2O7. After 50 h corrosion at 1300celcius, the corrosion depth in ZrO2-doped YTaO4 bulks is about 50-80 mu m (for a 20 mg/cm(2) CMAS deposition) in contrast with similar to 140 mu m in Gd2Zr2O7 bulk. The CMAS corrosion mechanism of ZrO2-doped YTaO4 is elucidated, and the excellent CMAS resistance is attributed to the rapid formation and followed thickening of dense reaction product layer. Furthermore, the effects of ZrO2 doping content on CMAS resistance of YTaO4 is discussed. It is elucidated that ZrO2 doping can inhibit the precipitation of apatite, decrease the consumption of CMAS melt, and change the morphology of dense reaction layer. In summary, minor doping of ZrO2 can ensure the excellent short- and long-term CMAS resistance, but heavy doping of ZrO2 will degrade the long-term CMAS resistance.

Automated summary

In this study, ZrO2-doped YTaO4 materials were investigated for their CMAS resistance, showing better performance compared to classical Gd2Zr2O7. The mechanism behind the improved resistance was attributed to the rapid formation and thickening of a dense reaction product layer facilitated by ZrO2 doping. It was also found that while minor ZrO2 doping enhances CMAS resistance, heavy doping can degrade long-term resistance.