Joining Properties of CoSb₃/Al/Ti/CuMo by Spark Plasma Sintering Process

Abstract

CoSb 3 -based skutterudite compounds are candidate materials for thermoelectric power generation in the mid-temperature range (600 -900 K) because their thermoelectric properties can be enhanced by doping and filling. The joining property of thermoelectric module electrodes containing thermoelectric materials is of great importance because it can dominate the efficiency of the thermoelectric module. This study examined the properties of CoSb 3 /Al/Ti/CuMo joined by the spark plasma sintering technique. Titanium thin foil was used to prevent the diffusion of copper into CoSb 3 and Aluminum thin foil was used to improve the adhesion between CoSb 3 and Ti. The insertion of an Aluminum interlayer between the Ti and CoSb 3 was effective for joining CoSb 3 to Ti by forming an intermediate layer at the Al-CoSb 3 boundary without any micro cracks. Specifically, the adhesion strength of the Ti/Al/ CoSb 3 joining interface showed a remarkable improvement compared with our previous results, without deterioration of electrical property in the interface.

Interaction of Skutterudites with Contact Materials: A Metallurgical Analysis

“…The diameter of the so obtained pseudo-spherical specimens ([ = 1.9-2.1 mm) was measured and these balls were embedded into the skutterudite matrixes via hot-pressing (56 MPa, 600°C, 2 h in 5 N Ar employing a uniaxial hot press Fig. 1 [36] B (Mo-Ti), [29] C (Ag-Pd), [34] D (Mo-Ti), [31,35] E (Al-Ti), [7,[37][38][39] F (Fe-Ni), [40] G (Al-Ni) [41] W200/250-2200-200-KS). The tablets with a diameter of 10 mm were vacuum-sealed in quartz tubes and heattreated at 600°C for 1100 h. The annealed cylinders were ground to the appearance of the embedded balls, and then polished using standard procedures.…”