熱電変換材料 アーク溶解法によるＢ４Ｃ‐ＴｉＢ２系複合セラミックスの作製とその熱電性能

Abstract

B4C-TiB2 quasi-binary composites were prepared by arc melting in argon atmosphere using B4C and TiB2 powders. Uniform lamella texture indicating eutectic reaction was observed at 25mol%TiB2 in the quasi-binary system. The electrical conductivity of the B4C-TiB2 composites significantly increased with increasing TiB2 content. The thermal conductivity (κ) of the composites containing 2mol%TiB2 was slightly smaller than that of B4C, but the κ values increased with increasing TiB2 content at more than 6mol%. The Seebeck coefficient of B4C-TiB2 composites showed maxima at 6mol%TiB2. The thermoelectric figure-of-merit (Z) values exponentially increased with increasing temperature, showing maxima at 6mol%TiB2. The greatest ZT values obtained in the present study was 0.55 at T=1100K for the composite containing 6mol%TiB2.