当前位置：首页 > 过刊浏览->2024年45卷第1期
同构合金化对P型ZrCoSb基 高熵half-Heusler合金热电性能的影响
Effects of Isomorphic Alloying on the Thermoelectric Properties of a P-type ZrCoSb-based High-entropy Half-Heusler Alloy
浏览(3226) 下载(10)
- DOI:
- 作者:
- 褚晨悦1，高一博1，范文新1，闫 宇1，张 文1，陈荣春1，康慧君1，2，王同敏1，2
CHU Chenyue1, GAO Yibo1, FAN Wenxin1, YAN Yu1, ZHANG Wen1, CHEN Rongchun1, KANG Huijun1,2, WANG Ton
- 作者单位:
- 1. 大连理工大学 材料科学与工程学院，辽宁省凝固控制与数字化制备技术重点实验室，大连 116024； 2. 大连理工大学宁波研究院，浙江 宁波 315000
1. Key Laboratory of Solidification Control and Digital Preparation Technology, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, China; 2. Ningbo Institute of Dalian University of Technology, Ningbo 315000, China
- 关键词:
- 热电材料；half-Heusler合金；ZrCoSb；晶格热导率
thermoelectric materials; half-Heusler alloy; ZrCoSb; lattice thermal conductivity
- 摘要:
Half-Heusler(HH)合金由于其本身具有较为优异的力学性能和高温热稳定性，已成为目前最具有应用前景的中高温热电材料之一。然而，其本身较高的本征晶格热导率阻碍了热电性能的进一步提升。本文以P型ZrCoSb0.85Sn0.15合金为研究对象，基于同构合金化具有优异P型热电性能的(Nb0.8Ta0.2)0.8Ti0.2FeSb，通过磁悬浮熔炼和放电等离子烧结设计并制备出一种(ZrCoSb0.85Sn0.15)1-x[(Nb0.8Ta0.2)0.8Ti0.2FeSb]x(x=0, 0.2, 0.3, 0.4, 0.5)高熵HH合金。微观组织分析表明，同构合金化这一策略引入了大量多尺度多衬度的第二相，这将有效增强对声子的散射。其中，当同构合金化含量为0.3时，晶格热导率在923 K时从ZrCoSb0.85Sn0.15的4.72 W·m-1·K-1降至3.07 W·m-1·K-1，降低了35%。然而，由于多位点合金化元素间存在较为复杂的掺杂效果，使其电导率和塞贝克系数同时降低，最终导致热电优值存在一定的降低。本研究工作表明，高熵合金设计思想是一种降低HH热电合金晶格热导率的有力措施。
Due to its excellent mechanical properties and high-temperature thermal stability, half-Heusler (HH) alloy has become one of the most promising medium- and high-temperature thermoelectric materials. However, its high intrinsic lattice thermal conductivity prevents further improvement of its thermoelectric properties. In this paper, the P-type ZrCoSb0.85Sn0.15 alloy is taken as the research object. Based on the isomorphic alloying of (Nb0.8Ta0.2)0.8Ti0.2FeSb with excellent P-type thermoelectric properties, high-entropy HH alloys (ZrCoSb0.85Sn0.15)1-x[(Nb0.8Ta0.2)0.8Ti0.2FeSb]x (x=0, 0.2, 0.3, 0.4, 0.5) were designed and prepared by magnetic levitation melting and spark plasma sintering. Microstructure analysis reveals that the isomorphic alloying strategy introduces many multi-scale and multi-contrast second phases, which effectively enhance the scattering of phonons. When the isomorphic alloying content is 0.3, the lattice thermal conductivity decreases by 35% from 4.72 W·m-1·K-1 for ZrCoSb0.85Sn0.15 to 3.07 W·m-1·K-1 at 923 K. However, due to the complex doping effect between the multi-site alloyed elements, the electrical conductivity and Seebeck coefficient decrease simultaneously, resulting in a certain decrease in the thermoelectric figure of merit. This work shows that the high-entropy alloy design approach is a powerful measure for reducing the lattice thermal conductivity of HH thermoelectric alloys.