화학공학소재연구정보센터
Journal of Materials Science, Vol.49, No.4, 1716-1723, 2014
Bonding and interfacial reaction between Ni foil and n-type PbTe thermoelectric materials for thermoelectric module applications
Integration of next generation thermoelectric materials in thermoelectric modules requires a novel or alternative approach for mating the brittle semiconducting thermoelectric materials and the ductile metal interconnects. In this study, pure Ni foil was directly bonded to PbTe-based thermoelectric materials using a rapid hot-press. The materials were sintered at 600 and 650 degrees C, under a pressure of 40 MPa and for various holding times. The resulting interfacial microstructures of the Ni/PbTe joints were investigated. Additionally, the distributions of elements and the phases formed at the Ni/PbTe interface were analyzed. The beta(2) phase (Ni3 +/- xTe2, 38.8-41 at.% Te) was identified at the Ni/PbTe joints bonded at both 600 and 650 degrees C. A ternary phase with approximate composition Ni5Pb2Te3 was found at the Ni/PbTe joints bonded at 650 degrees C. Additionally, the PbTe(Ni) phase was observed along the Ni grain boundaries for both bonding temperatures. Thermodynamics calculation results indicate that only the beta(2) phase can be formed at the Ni/PbTe interface at 900 K among the binary nickel tellurides.