论文标题
双相高渗透超高温度陶瓷
Dual-Phase High-Entropy Ultra-High Temperature Ceramics
论文作者
论文摘要
从n个二元硼化物和（5-n）二元碳化物粉末开始制造了一系列双相高渗透超高温度陶瓷（DPHE-UHTC）。几乎没有天然氧化物，已经达到了> 〜99％的相对密度。这些DPHE-UHTC由六角形高渗透硼（HEB）相和立方高脑碳化物（HEC）相组成。发现了一种在平衡中控制HEB和HEC相组成的热力学关系，并提出了热力学模型。这些DPHE-UHTC表现出可调的晶粒尺寸，Vickers Microhardness，Young'和Shear Moduli以及导热率。 DPHE-UHTC的硬度高于两个单相HEB和HEC的加权线性平均值，它们已经比单个二元硼化物和碳化物的混合规则平均值要难。这项研究通过引入双相高渗透陶瓷（DPHEC）来扩展艺术的状态，该陶瓷（DPHEC）通过更改相位分数和微结构来提供一个新的平台来量身定制各种特性。
A series of dual-phase high-entropy ultrahigh temperature ceramics (DPHE-UHTCs) are fabricated starting from N binary borides and (5-N) binary carbides powders. >~99% relative densities have been achieved with virtually no native oxides. These DPHE-UHTCs consist of a hexagonal high-entropy boride (HEB) phase and a cubic high-entropy carbide (HEC) phase. A thermodynamic relation that governs the compositions of the HEB and HEC phases in equilibrium is discovered and a thermodynamic model is proposed. These DPHE-UHTCs exhibit tunable grain size, Vickers microhardness, Young' and shear moduli, and thermal conductivity. The DPHE-UHTCs have higher hardness than the weighted linear average of the two single-phase HEB and HEC, which are already harder than the rule-of-mixture averages of individual binary borides and carbides. This study extends the state of the art by introducing dual-phase high-entropy ceramics (DPHECs), which provide a new platform to tailor various properties via changing the phase fraction and microstructure.
