Abstract With the development of aerospace and fusion engineering, understanding the mechanical behavior of materials under high-temperature conditions has become increasingly important. However, few studies are devoted to the ultra-high temperature range of 2000–3000 °C. In this study, with the aim of developing non-contact measuring techniques of mechanical deformation under ultra-high temperature, a high heat flux (~300 MW) comprehensive experimental platform is established, which includes a vacuum chamber, a three-dimensional digital image correlation (3D-DIC) system, infrared radiation thermometers and an electron beam heating system. Using the electron beam heating technique, the tungsten specimen can be heated to over 3000 °C. Owing to the use of a vacuum chamber, the thermally induced airflow disturbance at high temperature can be completely removed. Tantalum carbide (TaC) powder is chosen as the speckle material and speckle fabrication technology is developed to adapt ultra-high temperatures under vacuum conditions. In order to suppress the blackbody radiation at high temperature, three schemes based on blue light sources, self-radiating light sources and a dual wavelength optical filter technique are designed for three temperature ranges from room temperature to 3067 °C. Afterwards, full-field thermal deformation of the tungsten specimen above 3000 °C was determined based on the above strategies using the 3D-DIC technique. The feasibility and accuracy of the proposed methods are verified by comparing the measurement results with the thermal expansion strain data and model from available databases and literature. The standard deviations in different temperature intervals are 50 μe for 25–1200 °C, 100–200 μe for 1200–1800 °C and less than 500 μe for 1800–3067 °C. The proposed methods and technologies are expected to lay a foundation for further developments in strain field measurements at ultra-high temperature.

中文翻译：

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使用 3D 数字图像相关性进行 3000 °C 以上的应变场测量

摘要 随着航空航天和聚变工程的发展，了解材料在高温条件下的力学行为变得越来越重要。然而，很少有研究致力于 2000-3000°C 的超高温范围。本研究以开发超高温下机械变形的非接触测量技术为目标，建立了一个高热通量（~300 MW）综合实验平台，包括真空室、三维数字图像相关 (3D-DIC) 系统、红外辐射温度计和电子束加热系统。使用电子束加热技术，钨样品可以加热到 3000 °C 以上。由于使用真空室，可以完全消除高温下的热诱导气流扰动。选择碳化钽 (TaC) 粉末作为散斑材料，开发散斑制造技术以适应真空条件下的超高温。为了抑制高温下的黑体辐射，针对室温至3067℃三个温度范围设计了基于蓝光光源、自辐射光源和双波长滤光技术的三种方案。然后，基于上述策略使用 3D-DIC 技术确定了钨样品在 3000°C 以上的全场热变形。通过将测量结果与可用数据库和文献中的热膨胀应变数据和模型进行比较，验证了所提出方法的可行性和准确性。不同温度区间的标准偏差为 25–1200 °C 为 50 µe，1200–1800 °C 为 100–200 µe，1800–3067 °C 为小于 500 µe。所提出的方法和技术有望为超高温应变场测量的进一步发展奠定基础。