Fabrication of large scale FeSi/sub 2/ thermoelectric device

For the utilization of a number of waste heat from an incinerator or steel factory, the authors presented a novel design of large size thermoelectric device and spraying processing before. The objective of this work is to develop an process for fabricating advanced high power large size thermoelectric devices for various of processes, such as HP/HVOF (High Pressure, High Velocity Oxy-Fuel Spraying), CAPS (Controlled Atmosphere Plasma Spraying), HIP (Hot Isostatic Pressing), etc. To ensure a superior mechanical and thermoelectric property of the device, the technological determinants of the processes have been investigated, which included microstructures, powder size and powder shape of the material; and spraying temperature control on substratum during spraying processes. The thermal sprayings have been verified which are able to form a large size of FeSi/sub 2/ thermoelectric elements with thickness up to 5 mm. In comparison to the CAPS process, the HP/HVOF process of JP5000 is better in the aspects of thermoelectric property, cost, and mechanical property in that its controlled process creates a compressive stress in skin thickness of the device.