| β-FeSi2 is a thermoelectric material with powerful potential of application and development. It has great inoxidizability and plentiful resource and wonderful performance of thermoelectric during 200900℃, then less affect to environment. With the method of adulteration, it can make into semiconductor of n-type and p-type which avoid the problem of thermoelectric cell-making due to the difference of thermal expansivity.The thesis depended on the preparing methods of autoclave-SHS, SPS and hot-compression（HP）, then did the research of preparation of β-FeSi2 thermoelectric material and the analysis Mn-adulteration by consulting literature and doing experiments. Meanwhile,it researched the influence of preparative techniques and microstructure to the target materials by the methods of XRD 、 SEM/EDS and thermoelectrial measuring. The following are conclusions:Firstly, the paper tried to prepare the pure β-FeSi2 by autoclave SHS with the chemical reaction of Fe2O3+2Al+4Si=2FeSi2+Al2O3.As analysis measure resulted, the outcome has high purity with plenty of β phase under the condition of no further annealing heat treatment.Secondly, the research compared the influence of two preparative means to thermoelectric performance and surface micro-topography with same technological parameters of sintering temperature and holding temperature and time. Finally, the pilot tests used Fe and Si as the raw materials.As a result, the heat conductivity and electrical conductivity of specimen made by SPS are better than the consequence from heat-compression. Finally, the thesis did the analysis of the influence to β-FeSi2-making from mechanism of heat treatment and adulteration. As the results showing, the 1Wt.% of Mn is the best doping amount to SPS and heat-compression.It is associated to the reversal transformation of peritectoid transformation of α because of Mn,which facilitated β generated firstly into α. In addition,mixing too much Mn would give rise to forming α from β produced. |
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