State Key Laboratory of Advanced Technology for Materials Synthesis and Processing , Wuhan University of Technology , Wuhan , Hubei 430070 , China.
Department of Materials Science and Engineering , University of Washington , Seattle , Washington 98195 , United States.
ACS Appl Mater Interfaces. 2018 Apr 25;10(16):13669-13674. doi: 10.1021/acsami.8b01564. Epub 2018 Apr 10.
We report a nonequilibrium fabrication method of n-type CoSbTe skutterudites using selective laser melting (SLM) technology. A powder of CoSbTe was prepared by self-propagating high-temperature synthesis (SHS) and served as the raw material for the SLM process. The effect of SLM processing parameters such as the laser power and scanning speed on the quality of the forming CoSbTe thin layers was systematically analyzed, and the optimal processing window for SLM was determined. A brief postannealing at 450 °C for 4 h, following the SLM process, has resulted in a phase-pure CoSbTe bulk material deposited on a Ti substrate. The Seebeck coefficient of the annealed SLM prepared bulk material is close to that of the sample prepared by the traditional sintering method, and its maximum ZT value reached 0.56 at 823 K. Moreover, a Ti-Co-Sb ternary compound transition layer of about 70 μm in thickness was found at a dense interface between CoSbTe and the Ti substrate. The contact resistivity was measured as 37.1 μΩcm. The results demonstrate that SLM, coupled with postannealing, can be used for fabrication of incongruently melting skutterudite compounds on heterogeneous substrates. This lays an important foundation for the follow-up research utilizing energy efficient SHS and SLM processes in rapid printing of thermoelectric modules.
我们报告了一种使用选择性激光熔化 (SLM) 技术制备 n 型 CoSbTe skutterudites 的非平衡制造方法。CoSbTe 粉末通过自蔓延高温合成 (SHS) 制备，并用作 SLM 工艺的原料。系统分析了激光功率和扫描速度等 SLM 加工参数对形成的 CoSbTe 薄膜质量的影响，并确定了 SLM 的最佳加工窗口。在 SLM 工艺之后，进行 450°C 下 4 小时的短暂退火，导致在 Ti 基底上沉积了相纯的 CoSbTe 块状材料。退火的 SLM 制备块状材料的 Seebeck 系数接近传统烧结法制备的样品，其在 823 K 时的最大 ZT 值达到 0.56。此外，在 CoSbTe 和 Ti 基底之间的致密界面处发现了约 70μm 厚的 Ti-Co-Sb 三元化合物过渡层。接触电阻率测量为 37.1μΩcm。结果表明，SLM 与退火相结合可用于在异质基底上制造不相容熔化的 skutterudite 化合物。这为后续利用节能 SHS 和 SLM 工艺在热电模块的快速打印中的研究奠定了重要基础。
