【摘要】 采用Mg H2与Sn粉、Si粉通过固相反应法结合FAPAS法,实现了Mg2(Sn,Si)基热电材料的制备及快速致密化。采用Mg H2代替单质Mg粉与Sn粉、Si粉为原料进行固相反应可有效避免Mg单质的挥发和氧化。相较于纯Mg2Sn和纯Mg2Si样品,Mg2(Sn,Si)系列固溶体热导率显著降低,但同时电性能也有所下降,样品在500 K时获得最佳ZT值,其中Mg2Si0.5Sn0.5样品的ZT值最高,在500 K时达到0.18.Mg H2反应法由于反应温度低,容易实现,产品晶粒尺寸小,热电性能佳,对于制备Mg-Si体系热电材料有很大的优势。更多还原

【Abstract】 Mg2( Sn,Si)-based thermoelectric( TE) materials was prepared by a solid-state reaction between Mg H2 and Sn powder and Si powder by a field-activated and pressure-assisted sintering process( FAPAS) in order to realize rapid densification. Reaction between Sn or Si powder and magnesium hydride instead of pure magnesium minimizes the oxidation and volatilization of magnesium. The thermal conductivity of Mg2( Si,Sn) sosoloid was significantly lower than that of pure Mg2 Si and pure Mg2 Sn samples,but the electrical properties were also decreased,and the optimum ZT value was obtained at 500 K. Among them,the ZT value of Mg2Si0. 5Sn0. 5was the highest and reached 0. 18. The Mg H2 reaction method is easy to realize because of its lower reaction temperature.The grain size of the product was small and the thermoelectric properties were good. There is a great advantage in the preparation of Mg-Si system materials. The thermal conductivity was greatly reduced by the formation of Mg2( Sn,Si) sosoloid.更多还原