Abstract:
Using the Bi
0.4Sb
1.6Te
3+3%Te (mass fraction) melting crystal rods as the raw materials, the alloy ingots with good orientation were prepared by water-cooled copper crucible maglev melting technology. The P-type Bi
2Te
3-based alloy powders were obtained by grinding and sieving the alloy ingots with hammer. The P-type Bi
2Te
3-based thermoelectric materials with the preferred orientation along the (00
l) crystal face were prepared by vacuum hot pressing sintering technology. The micro-morphology and preferred orientation of the ingots, alloy powders and hot pressed sintered blocks were studied, as well as the effect of particle size on the electrical properties of the sintered blocks. The results show that the powders after quenching, crushing, and screening are highly oriented along the (00
l) crystal face. The blocks prepared by using 100~200 mesh size powders sintered at 500 ℃ and 40 MPa have the power factor of 44.5 μW·cm
−1·K
−2, which can cut the thin slices with the thickness of 0.3 mm, with the pass rate of more than 90%. Matching the conventional 127 pair 4 cm×4 cm thermoelectric cooler (TEC) with the zone melting N-type, the maximum temperature difference of the model TEC1-
12706 devices can reach 70 ℃, providing the preparation direction of the high-performance Bi
2Te
3-based thermoelectric materials.