High-temperature mechanical tests coupled with Digital Image Correlation (DIC) on ceramics which exhibit rather low level of strain require to overcome extreme experimental conditions that usually can reduce significantly measurement accuracy. Thermal resistance of speckle pattern, black body radiation and heat haze are three main concerns, which should thus be taken into account while designing a high-temperature image acquisition setup. In this aim, an experimental procedure has been specifically designed in order to minimize the three above-mentioned disturbances. The main objective of this study is to select a suitable high-temperature resistant speckle pattern for mechanical characterization at 1200 °C (or above) on refractory ceramics. Most of tested speckle patterns were performed with white alumina adhesive and dark ceramic grains (silicon carbide or brown fused alumina). Different grain sizes of silicon carbide were tested. At first, different speckle patterns are compared in terms of DIC strain measurement uncertainty by discussing speckle features, some main DIC parameters and two image pre-treatments (low pass filter, image size reduction). Then, these speckle patterns are tested to analyse fracture behaviour of refractories through a Brazilian test. An enhanced digital image correlation technique (2P-DIC), dedicated to monitor the fracture behaviour, is applied to study the evolution of crack length. The best representation of crack progression has been achieved for sample surface covered with a fine SiC powder ranging from 50 to 100 µm. It is then possible to compare the fracture behaviour between 1200 °C and 20 °C and to show that the refractory exhibits more crack branching at 1200 °C in comparison with behaviour at room temperature.

陶瓷上的高温机械测试与数字图像相关 (DIC) 相结合，表现出相当低的应变水平，需要克服通常会显着降低测量精度的极端实验条件。散斑图案的热阻、黑体辐射和热雾是三个主要问题，因此在设计高温图像采集装置时应考虑到这些问题。为此，专门设计了一个实验程序，以尽量减少上述三种干扰。本研究的主要目的是选择一种合适的耐高温散斑图案，用于在 1200 °C（或更高）温度下对耐火陶瓷进行机械表征。大多数测试散斑图案是用白色氧化铝粘合剂和深色陶瓷颗粒（碳化硅或棕色熔融氧化铝）进行的。测试了不同粒度的碳化硅。首先，通过讨论散斑特征、一些主要的 DIC 参数和两种图像预处理（低通滤波器、图像尺寸减小），在 DIC 应变测量不确定度方面比较不同的散斑图案。然后，测试这些斑点图案以通过巴西测试分析耐火材料的断裂行为。专用于监测断裂行为的增强型数字图像相关技术 (2P-DIC) 用于研究裂纹长度的演变。对于覆盖有 50 至 100 µm 细 SiC 粉末的样品表面，已经实现了裂纹进展的最佳表现。