FeSi_2 based thermoelectric materials have heen prepared by melt spinning andvacuum hot pressing. Most of the rapidly solidified (melt spinning) powders are thin flakes with athickness less than 0.1 mm. Scanning elect...FeSi_2 based thermoelectric materials have heen prepared by melt spinning andvacuum hot pressing. Most of the rapidly solidified (melt spinning) powders are thin flakes with athickness less than 0.1 mm. Scanning electron microscope (SEM) surface profiles show there arefurther finer grain structures with the characteristic size of about 100 nm in a flake. The samplesobtained by hot uniaxial pressing (HUP) in vacuum have densities higher than 90% the theoreticaldensity of the materials. It was found by SEM observations that the microstructures are verydifferent for vertical and parallel sections of the HUP samples. X-ray diffraction (XRD) analysesshow there are some texture features in the samples. It is considered that the textures of thesamples are originated from the orientation of the flakes that tended to align perpendicular to thehot press axis. WSi_2 was introduced into the powders unexpectedly during melting process before therapid solidification, but it makes the microstructures more easily to be explained.展开更多
基金This work was financially supported by the National Natural Science Foundation of China (NSFC 59971044) the International Bureau of the BMBF of Germany (CHN 01/361).
文摘FeSi_2 based thermoelectric materials have heen prepared by melt spinning andvacuum hot pressing. Most of the rapidly solidified (melt spinning) powders are thin flakes with athickness less than 0.1 mm. Scanning electron microscope (SEM) surface profiles show there arefurther finer grain structures with the characteristic size of about 100 nm in a flake. The samplesobtained by hot uniaxial pressing (HUP) in vacuum have densities higher than 90% the theoreticaldensity of the materials. It was found by SEM observations that the microstructures are verydifferent for vertical and parallel sections of the HUP samples. X-ray diffraction (XRD) analysesshow there are some texture features in the samples. It is considered that the textures of thesamples are originated from the orientation of the flakes that tended to align perpendicular to thehot press axis. WSi_2 was introduced into the powders unexpectedly during melting process before therapid solidification, but it makes the microstructures more easily to be explained.
