放电等离子烧结
材料科学
空位缺陷
碳化物
化学计量学
铪
哈夫尼亚
分析化学(期刊)
陶瓷
声子散射
金属
散射
热导率
热力学
凝聚态物理
锆
冶金
物理化学
复合材料
化学
物理
色谱法
光学
立方氧化锆
作者
Yuan Qin,Xiaofeng Wei,Jixuan Liu,Yongcheng Liang,Guo‐Jun Zhang
标识
DOI:10.1080/17436753.2023.2243120
摘要
ABSTRACTHigh-entropy carbide (Ti0.2xZr0.2xHf0.2x + (1-x)Nb0.2xTa0.2x)Cx (HEC-(1-x)Hf, x = 0.6-1) ceramics with 0-40 at.% nominal carbon vacancy were prepared by adding metal Hf into (Ti0.2Zr0.2Hf0.2Nb0.2Ta0.2)C (HEC) as a case study. The samples prepared by spark plasma sintering at 2000oC exhibit relative densities higher than 99%, single-phase rock salt structure, and homogeneous metal elements distribution. Their lattice parameters increase gradually with the added Hf content. The lattice parameter of HEC-0.4Hf is 0.86% higher than HEC's. The average grain size of the samples decreased initially, followed by an increase as Hf content increased, which is controlled by the comprehensive effect of Hf addition and carbon vacancy. The thermal conductivities of the samples decrease with the increase of Hf addition. HEC-0.4Hf has a very low thermal conductivity of 5.6 W/m·K at room temperature, which decreases 67.8% compared to HEC. The increased phonon scattering by the carbon vacancies can be the main reason for the reduced thermal conductivity.KEYWORDS: High-entropy carbidescarbon vacanciesmicrostructurethermal conductivity Disclosure statementNo potential conflict of interest was reported by the authors.Additional informationFundingThe present work was financially supported by the National Natural Science Foundation of China (No. 52032001, 52211540004) and the Fundamental Research Funds for the Central Universities (2232021A-01) and Graduate Student Innovation Fund of Donghua University (CUSF-DH-D-2023009).
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