A Ceramic Heat Flux Sensor With High Sensitivity for Ultrahigh Temperature

Precise heat flux measurement is of great importance in aerospace, energy, metallurgy, and so on. However, heat flux sensors still face high-temperature challenges such as low sensitivity, short survival time, and large size. In this work, we develop a ceramic heat flux sensor with minor junctions which shows outstanding performance for high temperatures. ITO-In2O3 is selected as the thermoelectric material to fabricate sensitive films. The films are produced by the screen-printing method with different paste formulas, and then evaluated through measuring micromorphology, thickness, roughness, crystallization, square resistance, and thermoelectric potential. The results show that the heat flux sensor reaches a sensitivity of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$76.8~\mu $ </tex-math></inline-formula>V/(kW/m2), and can measure heat flux up to 300 kW/m2 even the temperature beyond <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1200~^{\circ }$ </tex-math></inline-formula>C. Through the application tests, the heat flux sensor shows high capability to measure the heat flux of butane flame, air cooling, heat radiation, and engine tail flame. Our sensors provide a convenient and effective approach to monitoring the heat flux in the aerospace engine, pneumatic heating, and steel casting processes.