Bondability of Mg2Si element to Ni electrode using Al for thermoelectric modules

Abstract

The purpose of this study has been to develop a low cost bonding technique for thermoelectric Mg2Si/Si-Ge modules that provides reliable bonding. Aluminum was chosen as an alternative material to conventional silver alloy braze because of its cost advantage and bondability. The shear strength of an aluminum joint between a Mg2Si element and nickel electrode was 19 MPa. The generation capacity of a prototype Mg2Si/Si-Ge twin couple module was about 20% higher than that of a conventional Si-Ge/Si-Ge twin couple module at 923 K (ΔT 620 K).