Melt infiltrated SiC/SiC ceramic matrix composite unidirectional (UD) composite specimens were imaged under load using X‐ray microtomography techniques in order to visualize the evolution of damage accumulation and to quantify damage mechanisms within the composite such as matrix cracking and fiber breaking. The data obtained from these in situ tensile tests were used in comparison with current models and literature results. Three‐dimensional (3D) tomography images were used to measure the location and spacing of matrix cracking that occurred at increasing stress increments during testing within two UD composite specimens. The number of broken fibers and the location of each fiber break gap that occurred within the volume of both specimens were also quantified. The 3D locations of fiber breaks were correlated with the location of each matrix crack within the volume of the specimen and it was found that at the stress scanned directly before failure, most of the fiber breaks occur within 100 microns of a matrix crack.

中文翻译：

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X射线断层扫描显示SiC / SiC单向复合材料的损伤演变

使用X射线显微断层摄影技术在载荷作用下对熔渗的SiC / SiC陶瓷基复合材料单向（UD）复合标本成像，以可视化损伤累积的演变并量化复合材料内的损伤机理，例如基体开裂和纤维断裂。从这些原位拉伸试验获得的数据与当前模型和文献结果进行了比较。三维（3D）断层扫描图像用于测量在两个UD复合材料试样中的测试过程中应力增加时发生的基体裂纹的位置和间距。还定量了在两个样品的体积内发生的断裂纤维的数量和每个纤维断裂间隙的位置。