Theoretical investigations of the effects of ordered carbon vacancies in ZrC1−x on phase stability and thermo-mechanical properties

Abstract

The carbon deficiency and the ordering of carbon vacancies (VCs) in ZrC1−x are well known phenomena and significant for the performance management and service reliability. Using first-principles calculations to identify structural characteristics and stabilities, we report three kinds of vacancy-ordered phases, stable, metastable and “faulted” structures among vast ZrC1−x configurations. The intrinsic elasticity and hardness of ordered ZrC1−x are shown in linear dependence on carbon composition. In contrast, the thermal conductivity of ZrC1−x is not only dependent on the composition, but also strongly modified by the vacancy configuration. These results ensure the prediction of mechanical properties and also provide a guideline to tailor the thermal conductivity of ZrC1−x through tuning the VC characteristics. The variable-composition, diverse-configuration and tunable-property of ZrC1−x promise the engineering of its ordered phases, service performance and consequently the extension of its technological applications in the future.