Fabrication of Thermoelectric Mg₂Si by Mechanofusion and Pulsed Electric Current Sintering

Mg₂Si is a promising thermoelectric material because it is composed of non-toxic and "ubiquitous" elements, and development of an efficient production process for bulk Mg₂Si is important for the fabrication of thermoelectric devices. The mechanofusion (MF) process, which is an attrition type milling process, is attractive in terms of ease of use and collection of powder materials, in addition to a reduced risk of contamination since it requires no milling medium. In the present study, the MF process was applied to produce Mg₂Si powder, and pulsed electric current sintering (PECS) was then used to densify the powder. The density, microstructure and thermoelectric properties of the final bulk product were evaluated.