Preparation and Thermoelectric Properties of Joint of Chromel/Alumel Porous Sintered Compacts for Thermoelectric Transducer
Year: 1996
Type: article
Abstract: The miniaturization of a thermoelectric generator of gas combustion type requires a sharp temperature gradient between hot and cold junctions. It has been proposed by R. Echigo that this could be achieved by flowing a mixture of inflammable gas and air through the continuous coarse pores of a porous thermoelectric transducer and burning it at the outlet. The present article describes the preparation and thermoelectric properties of chromel/alumel porous sintered compact for the thermoelectric transducer. The average particle sizes of both chromel and alumel coarse powders were about 300 μm.Under the conditions of the relative density of green compact of 70%, sintering atmosphere of vacuum (10−3 Pa), sintering temperature of 1623 K and sintering time of 3.6∼14.4 ks, porous chromel and alumel sintered compacts having the following properties were obtained; continuous pores (porosity, 30%; relative density, 70%), appropriate mechanical property (bending strength at room temperature, above 90 MPa), specific electrical conductivity of about 2.5∼3.6×105 S·m−1 (ratios to the value of dense compact are about 17∼24%) and 10∼15×105 S·m−1 (23∼35%), respectively, and thermal conductivity of 7.1∼10 Wm−1 K−1 (23∼32%) and 13∼16 Wm−1 K−1 (32∼39%). And the porous thermoelectric transducer, i.e., joint of the two kinds of the sintered compacts having thermoelectric power of 4.2∼4.3×10−2 mV·K−1 (100%) and figure of merit of 2.2∼2.6×10−5 K−1 (76∼90%) were obtained under the same conditions.
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W2607241954