Continuously visualizing temperature inhomogeneity by thermal memory pigments with chromaticity-dependent non-stoichiometric Magnéli phase

Abstract

Thermal distribution is difficult to measure at the inner space of machine and systems with interference infrared noise signals, which could not be measured via infrared thermal camera. Herein, we proposed a thermal memory pigment coating method to direct visualizing and recording heat inhomogeneity. Tb₂O₃ was taken as a model material to demonstrate the heat recording based on continuously formation of Magnéli phase via non-stoichiometric oxidation process with temperature dependent irreversible thermochromism. The thermal memory mechanism was convicted by in-situ high-temperature x-ray diffraction, thermogravimetric, X-ray photoelectron spectroscopy techniques. Thermal inhomogeneity recording was achieved by recording the temperature distribution by infrared imager and validated by finite-element method in ABAQUS software. A comparison between the simulation results and experimental findings demonstrated that all three methods could effectively capture the thermal field distribution, yielding consistent results. This suggests that Tb₂O₃, with its thermal memory color-changing properties, can be used for thermal field identification, offering a more convenient and cost-effective alternative to infrared thermal imaging for thermal field recognition and recording.