Research for Brazing Materials of High-Temperature Thermoelectric Modules with CoSb3 Thermoelectric Materials

Metallic glass (MG) can be a candidate for an alternative brazing material of high-temperature thermoelectric modules, since we can expect both a lower brazing temperature and a high operating temperature for the junction from the MG brazers. Another advantage of MG powders is their outstanding oxidation resistance, namely, high-temperature durability in atmosphere. We fabricated three compositions of Al-based MGs-Al-Y-Ni, Al-Y-Ni-Co, and Al-Y-Ni-Co-La-by using the melt spinning process, and their T (g)s were 273A degrees C, 264A degrees C, and 249A degrees C, respectively. The electrical resistivity of the Al-Y-Ni MG ribbon dropped significantly after annealing at 300A degrees C. The electrical resistivity of crystallized Al-Y-Ni reduced down to 0.03 m Omega cm, which is an order of magnitude lower than that of the amorphous one. After the MG ribbons were pulverized to sub-100 mu m, the average particle size was about 400 mu m.