[Research Frontier] Haytham Chief Scientist Prof. Pan Bing's Team Makes New Progress in High-Temperature Synchronized Measurement

Recently,The research group of Haytham Technology chief scientist, Prof. Bing Pan of Beihang University, and Yu Liping made new progress in high-temperature thermal-mechanical testing, with results published in《Optics and Laser Technology》. The team proposed a laser speckle-assisted single-camera thermal variation instrument, achieving in the same camera, the same field of view and the same coordinate system, synchronized measurement of the temperature field and deformation field at high temperature, providing a new technical path for characterizing the thermal-mechanical coupling behavior of high-temperature materials.

In high-temperature material testing, temperature and deformation are two key parameters directly related to accurate acquisition of performance indicators such as thermal expansion coefficient and elastic modulus. Traditional testing usually relies on multiple devices — extensometers, thermocouples, infrared thermal imagers — to collect data separately; differences in sampling frequency, measurement field of view and coordinate reference between systems easily cause temporal and spatial mismatches, affecting the continuity and reliability of test results.

To address this problem, Prof. Pan Bing's team integrated laser speckle imaging and spectral beam-splitting imaging into a single camera system. A blue laser forms a stable speckle field on the specimen surface, andDIC analysis extracts full-field deformation; a three-band filter with a 3CCD color camera synchronously acquires thermal radiation signals in different bands, combined withtwo-wavelength ratio relationships and blackbody furnace calibration data to achieve full-field temperature inversion. The whole processrequires only one device, one calibration and one coordinate system, solving the spatiotemporal mismatch problem of traditional multi-device testing at the source.

Experimental results show that the system demonstrates good measurement capability in multiple scenarios:
▪ room temperature tensile test, the elastic modulus error＜5%；
▪ 600~1000℃ high-temperature thermal expansion experiment, the measured thermal expansion coefficient and the reference value differ by less than 7%；
▪ high-temperature tension at about 800℃ experiment, thestress-strain curve highly matches the material database, verifying its applicability under real high-temperature conditions.

This achievement provides a more compact and efficient non-contact measurement solution for testing high-temperature alloys, heat-resistant ceramics and advanced composites, and demonstrates the application potential of optical measurement technology in complex environments such as high temperature, strong radiation and limited space.

The research was also jointly funded by the National Key R&D Program, the National Natural Science Foundation and the Joint Technical Center for Aircraft Extreme Environment Mechanical Response Testing of AVIC,reflecting the state's continuous support and high attention to independent R&D of core technologies for high-temperature extreme environment testing.

From frontier research to application,Haytham Technology always pays attention to the development direction of optical measurement technology. In the future, we will continue to push vision measurement technology toward higher precision and higher integration, providing more valuable technical support for research and engineering scenarios.