Optimal imaging of digital image correlation speckle under high temperature

In order to measure the mechanical properties of materials at high temperatures or even at ultra-high temperatures, digital image correlation methods are used and their optimal imaging at high temperatures is studied. Different speckle production methods are adopted and high temperature paints of different colors are added. At different temperature nodes, different light sources and corresponding filters are added to collect and observe whether the image has a good contrast. The ordinary monochromatic light source will gradually fail after 800℃, and the image cannot be obtained. The ultraviolet light can still obtain a better image at 1 200℃, and the color of the test piece itself is better as the background color. UV light illumination can be used to measure DIC in high temperature environment. At the same time, the use of black or blue speckle directly sprayed on the test piece has the best contrast, which is superior to the conventional speckle making method.