Ageing properties of thermally sprayed iron disilicide

The relation between the microstructure and the thermal and thermoelectric behaviour of thermally sprayed p- and n-type FeSi₂ has been investigated in order to identify process variations and operation conditions to obtain good thermoelectric properties. For comparison of materials from different spraying techniques hot pressed standard material is considered. The investigation of the correlation between the thermal and electrical properties on the one hand and microstructural features on the other hand is based on the measurements of transport properties (Seebeck coefficient, thermal diffusivity, electrical conductivity) combined with imaging and analytical methods (REM, EDX, XRD). These are recorded during a step-wise annealing throughout an overall period of 500 h