Microstructures and thermoelectric properties of Co-doped iron disilicides prepared by rapid solidification and hot pressing

摘要: Abstract Iron disilicide based alloys Fe 0.94 Co 0.06 Si 2.00 were prepared by rapid solidification and hot uniaxial pressing. The effects of pre-annealing the powders pressing temperature on microstructures thermoelectric properties investigated. X-ray diffraction scanning electron microscopy show that after at 800 °C for only 2 h, high phases (α-Fe 2 5 ɛ-FeSi) in rapidly solidified have been completely transformed to β-FeSi phase, while fine grain structures maintained. It is found growth during was successfully suppressed pre-annealed samples, especially a lower 880 °C. Seebeck coefficient markedly enhanced treatment, also temperature, both electrical conductivity thermal decreased them. maximum dimensionless figure merit ZT  = 0.25 908 K obtained , which pre-annealed, followed 880 °C with 70 MPa 30 min.