机械合金化和放电等离子烧结制备AgPbSbTe热电材料

AgPbSbTe Thermoelectric Materials Fabricated by Mechanical Alloying and Spark Plasma Sintering(SPS)

采用机械合金化和放电等离子烧结方法制备高性能AgPbSbTe热电材料,研究了制备工艺对材料热电性能的影响。结果表明,材料的物相组成和热电性能都受到机械合金化时间的影响;适当地控制放电等离子烧结工艺可以抑制晶粒长大,增加晶界散射,降低热导率。实验中得到AgPbSbTe热电材料的最大功率因子为18μW/K^2cm,最小热导率为1.1 W/m K。机械合金化(球磨4 h、转速350 r/m)并在673 K放电等离子烧结5 min,得到AgPbSbTe材料的最大热电优值ZT为1.2(700 K)。

High performance AgPbSbTe thermoelectric materials were fabricated by mechanical alloying（MA） and spark plasma sintering（SPS）.The effect of preparation technique on the thermoelectric properties was studied.The results showed that the phase composition and thermoelectric properties are related to the mechanical alloying.Appropriate SPS technique could decrease crystal growing,increase phonon scattering and reduce thermal conductivity.A maximum power factor of 18μW/K^2cm and a minimum thermal conductivity of 1.1 W/m K were obtained.A maximum ZT value of 1.2 was obtained at 700 K for the sample fabricated by MA（350 rpm for 4 hrs） and SPS（sintering at 673 K for 5 minute）.