Improved multispectral pyrometry for synchronous full-field temperature and deformation measurement at elevated temperatures

Accurate full-field measurement of temperature and deformation in high-temperature environments has been a critical challenge in materials science, yet current research remains limited, particularly concerning the application of multispectral imaging for comprehensive thermal assessments. Traditional measurement methods often struggle with precision due to the coupling of reflection and emitted radiation, leading to uncertainties and inadequate data in extreme thermal conditions. This work addresses this issue by presenting an improved multispectral pyrometry for full-field temperature measurement and synchronous deformation assessment. We developed a nine-channel multispectral imaging system, facilitating the simultaneous capture of radiative energy across multiple narrow-band wavelengths. By employing a channel separation strategy in conjunction with digital image correlation (DIC) techniques, our system effectively decouples the contributions of temperature and deformation, ensuring spatial and temporal consistency. Validation through flame ablation experiments on C/SiC composites demonstrated the reliability and accuracy of our method. The findings underscore the potential of our improved multispectral pyrometry to enhance measurement precision and fill the existing research void in high-temperature applications.