Making High Thermoelectric and Superior Mechanical Performance Nb<sub>0.88</sub>Hf<sub>0.12</sub>FeSb Half‐Heusler via Additive Manufacturing
Zhifu Yao, Wenbin Qiu, Chen Chen, Xin Bao, Kaiyi Luo, Yong Deng, Wenhua Xue, Xiaofang Li, Qiujun Hu, Junbiao Guo, Lei Yang, Wenyu Hu, Xiaoyi Wang, Xingjun Liu, Qian Zhang, Katsumi Tanigaki, Jun Tang
Abstract
Abstract Thermoelectric generators held great promise through energy harvesting from waste heat. Their practical application, however, is greatly constrained by poor raw material utilization and tedious processing in fabricating desired shapes. Herein, a state‐of‐the‐art process is reported for 3D printing the half‐Heusler (Nb 0.88 Hf 0.12 FeSb) thermoelectric material using laser powder bed fusion (LPBF). The multi‐dimensional intra‐ and inter‐granular defects created by this process greatly suppress thermal conductivity by providing numerous phonon scattering centers. The resulting LPBF‐fabricated half‐Heusler exhibits a high figure of merit ≈1.2 at 923 K and a single‐leg maximum efficiency of ≈3.3% at a temperature difference ( ΔT ) of 371 K. Hafnium oxide nanoparticles generated during LPBF effectively prevent crack propagation, ensuring competent mechanical performance and reliable thermoelectric output. The findings highlight the significant potential of LPBF in driving the next industrial revolution of highly efficient and customizable thermoelectric materials.