Time-gated active imaging digital image correlation for deformation measurement at high temperatures

We proposed a novel time-gated active imaging digital image correlation (DIC) method based on bandpass filtering and gated single-photon imaging techniques for high-temperature deformation measurement. The proposed method uses a powerful pulsed laser for illumination and then records the reflected pulsed laser light using a gated single-photon camera with an ultrashort exposure time. As a result, the received radiation light from the heated object and the ambient light can be significantly reduced to a negligible level compared with the illumination light intensity from the pulsed laser. Experiments including the varying ambient light test and thermal deformation measurement of a Ni-based alloy at around 700 C verified the performance of the proposed method. It is observed that the established time-gated active imaging DIC system is dramatically superior to existing blue light DIC and ultraviolet-DIC (UV-DIC) systems in preserving the image quality at high temperatures, thus showing promising application prospects in extremely challenging scenarios, such as ultra-high temperature material testing, or thermomechanical testing of hypersonic materials and structures subjected to transient aerodynamic heating simulated by quartz lamps or an arc-heated wind tunnel. (C) 2022 Elsevier Ltd. All rights reserved.

Automated summary

A novel time-gated active imaging DIC method based on bandpass filtering and gated single-photon imaging techniques is proposed for high-temperature deformation measurement. This method maintains image quality at high temperatures and shows promising application prospects.