来源：Science Direct
ZrB2-SiC ceramic composites are susceptible to severe oxidation corrosion at 1700 ℃ in oxidizing atmospheres, owing to rapid B2O3 volatilization, ZrO2-transformation-induced cracking, insufficient fluidity of the SiO2 glassy phase, and the resulting loss of oxide scale integrity. Here, nanosized (YxYb1-x)2O3 solid-solution oxides were synthesized and incorporated into ZrB2-SiC composites to develop a dual rare-earth modification strategy. The influence of the Y3+/Yb3+ synergistic effect on the isothermal oxidation behavior at 1700 ℃ and on the residual mechanical properties after oxidation was investigated. Dual-rare-earth solid solutions simultaneously stabilize the ZrO2 phase, modify the SiO2 glass phase, and reinforce interfaces, thereby achieving enhanced oxidation resistance and high-temperature mechanical stability. For the ZrB2-SiC-(Y0.9Yb0.1)2O3 sample, mass gain per unit area and oxide-scale thickness decreased by 44.79% and 69.16%, respectively. Compared with the unmodified sample, while all modified samples exhibited hardness retention above 94.00% and flexural-strength retention above 78.00%. The improvement in oxygen barrier property is attributed to co-dissolution of Y3+ and Yb3+ into the ZrO2 lattice, effectively suppressing the t→m transformation of ZrO2, eliminating transformation-induced volume expansion and microcracking, while Yb3+ incorporation into the SiO2 glass network forms a continuous, dense Zr-Y-Yb-Si-O barrier layer with enhanced high-temperature fluidity and self-healing capability. The dual-rare-earth synergism therefore promotes highly efficient protection through integrated oxidation resistance and mechanical stability. This study provides new insights into the development of dual rare-earth synergistic protection for ultra-high temperature ceramics.