High-entropy ceramics have recently attracted considerable attentions because of excellent combination of exceptional properties. In this work, the temperature dependent elastic properties of (ZrTaNbTi)C have been systematically studied from the density functional perturbation theory combined with self-consistent quasi-harmonic approximation. High entropy ceramic (ZrTaNbTi)C is thermodynamically stable due to the negative formation enthalpy, and is also mechanically stable from the obtained elastic properties. The phonon dispersion relation computed at equilibrium volume contains no imaginary-frequency, implying the dynamical stability. At 0 K, (ZrTaNbTi)C possesses evidently high elastic moduli and hardness. The calculated electronic density of state and Bader charge at 0 K and 2000 K show that (ZrTaNbTi)C have covalent characteristics accompanied by ionic feature while the covalency decreases and the ionicity increases as temperature increases. The temperature-dependent elastic properties show that (ZrTaNbTi)C is mechanically stable in temperature range studied, and remains high strength and hardness at high temperature due to the slight softening of strong covalent bonding. Poisson's ratio, Pugh's ratio and Cauchy pressure suggest the higher brittle-ductile transformation trend as the temperature increases. Moreover, (ZrTaNbTi)C shows less anisotropy at higher temperature from the Zener index A^Z and three-dimensional projections, being beneficial to reduce cracking and improve durability. The present study provides more insight into the high temperature behavior of mechanical properties, would be valuable for understanding and design of high-temperature properties of high entropy carbide ceramics.

高熵陶瓷因其优异的性能组合最近引起了相当大的关注。在这项工作中，已经从密度泛函微扰理论结合自洽准谐波近似系统地研究了 (ZrTaNbTi)C 的温度相关弹性特性。由于形成焓为负，高熵陶瓷 (ZrTaNbTi)C 在热力学上是稳定的，并且从获得的弹性性能来看也是机械稳定的。在平衡体积下计算的声子色散关系不包含虚频，这意味着动态稳定性。在 0 K 时，(ZrTaNbTi)C 具有明显高的弹性模量和硬度。计算的 0 K 和 2000 K 状态和巴德电荷的电子密度表明 (ZrTaNbTi)C 具有共价特性，伴随着离子特性，而随着温度的升高，共价性降低，离子性增加。随温度变化的弹性性能表明 (ZrTaNbTi)C 在研究的温度范围内机械稳定，并且由于强共价键的轻微软化而在高温下保持高强度和硬度。泊松比、Pugh 比和柯西压力表明随着温度升高，脆-韧转变趋势更高。此外，(ZrTaNbTi)C 在较高温度下从齐纳指数显示出较小的各向异性 随温度变化的弹性性能表明 (ZrTaNbTi)C 在研究的温度范围内机械稳定，并且由于强共价键的轻微软化而在高温下保持高强度和硬度。Poisson 比、Pugh 比和 Cauchy 压力表明随着温度升高，脆-韧转变趋势更高。此外，(ZrTaNbTi)C 在较高温度下从齐纳指数显示出较小的各向异性 随温度变化的弹性性能表明 (ZrTaNbTi)C 在研究的温度范围内机械稳定，并且由于强共价键的轻微软化而在高温下保持高强度和硬度。Poisson 比、Pugh 比和 Cauchy 压力表明随着温度升高，脆-韧转变趋势更高。此外，(ZrTaNbTi)C 在较高温度下从齐纳指数显示出较小的各向异性A ^Z和三维投影，有利于减少开裂和提高耐用性。本研究提供了对机械性能的高温行为的更多见解，对于理解和设计高熵碳化物陶瓷的高温性能具有重要价值。