Process optimisation enhancing thermoelectric and mechanical performance in reactive in-situ spark plasma sintered Mg2(Si,Sn)

Rapid, reactive in-situ spark plasma sintering was employed for the fabrication of n-type Mg-2(Si,Sn) material via optimising the sintering temperature. This reaction sintering process resulted in an excellent thermoelectric and mechanical performance in the Mg-2(Si,Sn) alloy, which is recognised as a good earth-abundant, non-toxic, and low-cost, intermediate- temperature-application thermoelectric material. The phase structure and composition of the synthesised alloy were investigated employing X-ray diffraction, field emission scanning electron microscopy, and energy-dispersive spectroscopy. The optimized figure of merit (ZT) similar or equal to 0.4 associated with a high hardness similar to 450 Hv and a high fracture strength similar to 1.4 MPa root m were achieved in spark plasma sintered Mg-2(Si,Sn) material. This work also reports the thermoelectric and mechanical properties of Mg-2(Si,Sn) material and correlates them with the processing parameters.