Unraveling the oxidation behavior and mechanism of (TiZrTaNbCr)C high-entropy ceramic by introducing Cr3C2

High-entropy carbide ceramic materials exhibited excellent thermal and mechanical properties, making them highly sought after in high-temperature applications. However, the oxidation resistance of high-entropy carbide ceramic needed to be further improved. This work unraveled the oxidation behavior and mechanism of highentropy carbide ceramic by introducing the Cr3C2. The results indicated that the oxidation rate of (TiZrTaNbCr)C initially decreased with temperature up to 900 degrees C, followed by an increased with further temperature rise up to 1100 degrees C. At 800 and 900 degrees C, the parabolic oxidation rate constants were 0.70 and 0.17 mg2cm 4min 1, respectively. And the minimum thickness of oxidized layer was 60 mu m at 900 degrees C for 120 min. This unusual phenomenon suggested the formation of different oxidation products. Specifically, the CrNbO4 and Nb2Zr6O17 oxide layer were formed at 900 degrees C, leading to an increased resistance to oxygen diffusion. Subsequently, loose oxidation products of Nb2O5 were formed after 1000 degrees C, hindering the oxidation resistance. In the current study on oxidation resistance of high entropy carbides, this work showed a competitive performance. Overall, this study illustrated the oxidation mechanism and behavior of (TiZrTaNbCr)C and proposed a new avenue for the design of high-entropy ceramic components.