Thermoelectric properties of n-type ZrNiSn prepared by rapid non-equilibrium laser processing.

The traditional manufacturing of thermoelectric (TE) modules is a complex process that requires a long processing time and is high cost. In this work, we introduce a novel one-step 3D printing technique for TE module manufacturing, which integrates the Self-propagation High-temperature Synthesis (SHS) with the Selective Laser Melting (SLM) method. As a demonstration of this technique, bulk ZrNiSn samples were successfully fabricated on a Ti substrate. The effect of SLM processing parameters, such as the laser power and the scanning speed, on the quality of the forming ZrNiSn layers was systematically studied and analyzed, and the optimal processing window for the SLM process was determined. Transport property measurements indicate that the SLM-processed ZrNiSn possesses the maximum thermoelectric figure of merit of 0.39 at 873 K. The interface of the ZrNiSn with the Ti substrate shows good adherence and low contact resistivity. The work demonstrates the viability of the SHS-SLM method for rapid fabrication of TE materials, legs and even modules.