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

[Display omitted] •Synthesis of Mg2(Si,Sn) employing a rapid, in-situ reactive SPS process.•Excellent thermoelectric and mechanical properties via process parameter optimisation.•The high hardness value of ∼450 Hv in reactive, SPS synthesised Mg2(Si,Sn).•The excellent fracture toughness value of ∼1.4 MPa√m in Mg2(Si,Sn) material. Rapid, reactive in-situ spark plasma sintering was employed for the fabrication of n-type Mg2(Si,Sn) material via optimising the sintering temperature. This reaction sintering process resulted in an excellent thermoelectric and mechanical performance in the Mg2(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) ≃ 0.4 associated with a high hardness ∼450 Hv and a high fracture strength ∼1.4 MPa√m were achieved in spark plasma sintered Mg2(Si,Sn) material. This work also reports the thermoelectric and mechanical properties of Mg2(Si,Sn) material and correlates them with the processing parameters.