Enhancing the Thermoelectric and Mechanical Properties of CuNiMn Alloys by Introducing Si Impurity Atoms and Twins
Enhancing the Thermoelectric and Mechanical Properties of CuNiMn Alloys by Introducing Si Impurity Atoms and Twins
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DOI：
10.1021/acsaelm.3c01011
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发表时间：
2023-09
影响因子：
4.7
通讯作者：
Xinghao Cao;Jianbo Li;Jiajun Zhang;Mingyang Li;Huijun Kang;E. Guo;Zongning Chen;Rongchun Chen;Jun Wang;Tongmin Wang
中科院分区：
文献类型：
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作者：
Xinghao Cao;Jianbo Li;Jiajun Zhang;Mingyang Li;Huijun Kang;E. Guo;Zongning Chen;Rongchun Chen;Jun Wang;Tongmin Wang
Constantan(铜镍合金)具有较低的电阻率温度系数和良好的热电性能，已成功应用于精密电阻、热电偶等器件。CuNiMn合金的高功率因数使其具有比传统热电材料更高的输出功率密度。然而，作为一种具有固有金属性质的合金，其较高的导热系数也是限制其热电性能进一步提高的重要因素。本研究通过熔炼和轧制的方法制备了掺硅的CuNiMn合金。深冷处理后的CuNiMn-2.0原子%Si合金在773K时的导热系数为29.96Wm-1K-1，比原始合金的导热系数降低了36.2%。此外，深冷处理的Cu56Ni42Mn2-2.0原子%Si合金在773K时的热电优值达到0.17，比铸态Cu56Ni42Mn2的热电优值提高47%。合金导热系数的降低归因于固溶体原子、位错和孪晶界的引入增强了不同频率下的声子散射。这些结果为同时优化CuNiMn基合金的热电性能和力学性能提供了解决方案。
Constantan (Cu–Ni alloy) has been successfully applied in precision resistors, thermocouples, and other devices because of its low-temperature coefficient of resistivity and favorable thermoelectric properties. The high power factor of CuNiMn alloys endows them with a higher output power density than those of conventional thermoelectric materials. However, as an alloy with intrinsic metallic properties, its high thermal conductivity is also an important factor that limits further improvement in its thermoelectric properties. In this study, CuNiMn alloys doped with Si atoms were prepared by melting and rolling. The thermal conductivity of the cryorolled CuNiMn-2.0 atom % Si alloy decreased effectively to 29.96 W m–1K–1at 773 K, which is 36.2% lower than that of the pristine alloy. Moreover, the thermoelectric figure of merit of the cryorolled Cu56Ni42Mn2-2.0 atom % Si alloy reached 0.17 at 773 K, which is 47% higher than that of the as-cast Cu56Ni42Mn2sample. The decreased thermal conductivity of the alloy is attributed to intensified phonon scattering at various frequencies due to the introduction of solid-solution atoms, dislocations, and twin boundaries. These results provide a solution to optimize simultaneously the thermoelectric and mechanical properties for CuNiMn-based alloys.