Author_Institution :
Inst. of Mater. Res., German Aerosp. Res. Establ., Koln, Germany
Abstract :
According to the literature, Mg2Si possesses good thermoelectric properties, However, no easy fabrication process for this material is known to date, In this paper we present a new production route based on modified mechanical alloying and hot uniaxial pressing that leads to samples free from oxides, Comparison is made with samples produced by a conventional powder metallurgical process leading to the contamination with MgO. The samples were examined by differential scanning calorimetry, laser flash-, Hall-, and Seebeck-measurements. The results show that the samples free from oxides have an improved thermal stability, a higher thermal conductivity and a much higher Hall mobility. Thus, the thermoelectric figure of merit z could be improved by a factor of 3.5. Additionally, the electronic transport behaviour of the oxide-free samples was examined. It can be explained by the contribution of an additional conduction band
Keywords :
Hall effect; Hall mobility; Seebeck effect; conduction bands; hot pressing; magnesium alloys; mechanical alloying; powder metallurgy; silicon alloys; thermal analysis; thermal conductivity; thermal stability; Hall mobility; Hall-measurements; Mg2Si; MgO; Seebeck-measurements; conduction band; differential scanning calorimetry; electronic transport behaviour; fabrication process; hot uniaxial pressing; laser flash-measurements; modified mechanical alloying; powder metallurgical process; production parameters; thermal conductivity; thermal stability; thermoelectric figure of merit; thermoelectric properties; Alloying; Environmentally friendly manufacturing techniques; Fabrication; Inorganic materials; Lead compounds; Mechanical factors; Pressing; Production; Thermal conductivity; Thermoelectricity;
