| Title |
The Influence of Extrusion Ratio on Microstructures and Thermoelectric Properties of Rapidly Solidified N-type Bi2Te2.75Se0.15 Thermoelectric Materials |
| Authors |
김태경(Tae Kyung Kim); 이상일(Sang Il Lee); 임종호(Jong Ho Lim); 손현택(Hyeon Taek Son); 김택수(Taek Soo Kim); 천병선(Byong Sun Chun) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
Thermoelectric properties; Extrusion ratio; Compressive strength; Bi2Te2.75Se0.15 |
| Abstract |
The n-Type thermoelectric compounds of Bi₂Te_(2.75)Se_(0.15) doped with 0.1 wt% SbI₃ were fabricated by gas atomization process and extruded under ratio of 16:1 and 28:1 at 450℃. The effect of extrusion ratio on the microstructures and thermoelectric properties were investigated by a combination of microscopy, XRD and thermoelectric properties. Grains of extruded bars are smaller than those of heated powder at extrusion temperature (450℃) due to the dynamic recrystallization but with increasing the amount of plastic deformation, grains of specimen extruded with 28:1 were slightly coarse. The compressive strength of hot extruded bar under 28:1 is 160 MPa and with decreasing the extrusion ratio to 16:1, the value is 250 MPa. The Seebeck coefficient a and electrical resistivity p were decreased with increasing ratio, while thermal conductivity x was increased. this results from decrease of carrier scattering and increase of carrier mobility. Extruded bar under ratio of 16:1 shows the higher value of figure of merit (Z=2.50x10^(-3)/K) than that of 28:1 (Z=2.07x10^(-3)/K). (Received June 24, 2004) |