SiC/SiC composites reinforced with 3^rd generation SiC fibers (Hi-Nicalon S and Tyranno SA3 fibers) are promising candidates for thermomechanical applications in high technology industries. Both composites exhibited a pseudo-ductile mechanical behavior but the HNS/PyC/SiC composite reaches higher failure strains than TSA3/PyC/SiC ones. The mechanical behavior of SiC/SiC composites is linked to the way PyC is bonded to the fiber surface. Analyses have shown that these interactions and the Fiber/Matrix debonding behavior depend strongly on the nature of the carbon on the SiC fiber surface, which is different according to the SiC fiber. In order to understand the mechanism governing the chemical adhesion at the PyC/SiC fiber interface, the formation, the chemistry and the structure of the surface carbon layer were studied. Understanding the origin of this carbon has allowed elucidating the local interaction mechanisms of the studied SiC/SiC composites.

的SiC / SiC复合材料具有增强的3^次新一代SiC纤维（Hi-Nicalon S和Tyranno SA3纤维）是高科技行业中热机械应用的有希望的候选者。两种复合材料均表现出拟延性力学性能，但HNS / PyC / SiC复合材料比TSA3 / PyC / SiC复合材料具有更高的破坏应变。SiC / SiC复合材料的机械性能与PyC粘结到纤维表面的方式有关。分析表明，这些相互作用和纤维/基体的脱粘行为在很大程度上取决于SiC纤维表面上碳的性质，而该性质随SiC纤维的不同而不同。为了理解控制PyC / SiC纤维界面化学粘附的机理，研究了表面碳层的形成，化学性质和结构。