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以Bi_2Te_(2.7)Se_(0.3)为基础配比,99.99%的高纯Te、Bi、Se为原料,通过高温真空熔炼合金化-无氧环境机械粉碎-精密筛分制粉-独创热压装置快速热压工艺,制备出块体n型碲化铋基热电材料。采用粒度分析仪、扫描电镜、氧氮分析仪对合金粉末的粒度和氧含量进行了测定,用X射线衍射仪对合金粉末的物相结构进行了表征,并对热压块体样品的抗弯强度进行测试。热电性能测试结果显示,所制备热压块体样品不同方向的Seebeck系数和ZT值(热电优值系数)基本相同,但电阻率和热导率有不同程度的取向,但与市购区熔热电材料相比取向度明显降低。热压块体样品的相对密度高达99%,抗弯强度达到87 MPa,最高ZT值约为0.7。该工艺的生产设备简单可靠,生产成本低,工作效率高,适合产业化。
Based on Bi_2Te_ (2.7) Se_ (0.3), 99.99% of high purity Te, Bi and Se are used as raw materials and alloyed by high-temperature vacuum smelting - anaerobic environment mechanical comminution - precision sieving powder - original hot pressing device Rapid hot pressing process to prepare a bulk n-type bismuth telluride based thermoelectric material. The particle size and oxygen content of the alloy powders were determined by particle size analyzer, scanning electron microscopy, oxygen and nitrogen analyzer. The phase structure of the alloy powders was characterized by X-ray diffractometer. Strength test. The results of the thermoelectric test show that the Seebeck coefficient and the ZT value (thermoelectric figure of merit) of the prepared hot-pressed bulk samples are basically the same, but the resistivity and the thermal conductivity have different degrees of orientation, Material compared to the degree of orientation was significantly reduced. The relative density of hot-pressed bulk samples was as high as 99%, the flexural strength reached 87 MPa, and the highest ZT value was about 0.7. The process of production equipment is simple and reliable, low production costs, high efficiency, suitable for industrialization.