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采用真空熔融淬火结合等离子活化烧结工艺(PAS)制备SiC/β-Zn_4Sb_3复合热电材料。对材料的相组成和显微结构分别进行X射线衍射分析和扫描电子显微镜观察,并在300~700 K范围内测量了电阻率、Seebeck系数、热导率。结果表明,复合材料由SiC和β-Zn_4Sb_3两相组成,PAS烧结过程中,β-Zn_4Sb_3并没有发生相变,SiC纳米粒子在β-Zn_4Sb_3基体中随机分布。随着纳米SiC含量增加,复合材料的电阻率逐渐增加,Seebeck系数先增加后降低。当SiC含量为1.0%(质量分数)、673 K时,复合材料的热电优值(ZT)达到1.03,与单相β-Zn_4Sb_3相比提高了37%。
SiC / β-Zn_4Sb_3 composite thermoelectric materials were prepared by vacuum melting and plasma activated sintering (PAS). The phase composition and microstructure of the material were observed by X-ray diffraction and scanning electron microscope respectively. The resistivity, Seebeck coefficient and thermal conductivity were measured in the range of 300-700 K. The results show that the composites consist of two phases of SiC and β-Zn 4 Sb 3, and the phase transition of β-Zn 4 Sb 3 does not occur during the PAS sintering. The SiC nanoparticles are randomly distributed in the β-Zn 4 Sb 3 matrix. With the increase of nano-SiC content, the resistivity of the composites increases gradually, and the Seebeck coefficient first increases and then decreases. When the SiC content is 1.0% (mass fraction) and 673 K, the thermoelectric figure of merit (ZT) of composite reaches 1.03, which is 37% higher than that of single-phase β-Zn_4Sb_3.