Impact of mesostructure on the strength and failure mode of textile SiC/SiC blade tips

The mechanical properties of nine different microstructural designs of textile-type SiC/SiC blade tip specimens prepared using the chemical vapor penetration process were compared and analyzed through static tensile tests at room temperature. The failure process was monitored in real time using an acoustic emission (AE) system and digital image correlation (DIC) technology, combined with scanning electron microscopy (SEM) analysis of the macrostructural and microstructural fracture morphology of the specimens, ultimately revealing the influence of microstructure on the failure mode. The results showed that: (a) the stranded-partially interlaced connection scheme had the highest average failure strength, reaching a maximum of 5.26 kN; (b) among the three layered structure schemes and three stranded schemes, the partially interlaced structure exhibited the highest strength, followed by the non-interlaced structure, with the fully interlaced structure having the lowest strength; (c) Increasing the complexity of yarn weaving at the blade-to-tip connection location enhances load-bearing capacity but reduces the conformity of specimen shape to design values, and also increases fiber bundle wear during weaving, leading to a decline in fiber performance.