High temperature fiber pushout of pristine and transversely fatigued SiC/Ti-6-4

摘要

Preliminary pushout tests on both a pristine and atransversely fatigued SiC/Ti-6-4 composite were conducted inatmospheric conditions to assess the capabilities of this apparatusand to study the interfacial behavior of SiC/Ti-6-4 at elevatedtemperature. At room temperature, the force-displacementbehavior for the two types of samples was similar. The frictionalportion of the load-displacement curve following total debondindicated that the interface could carry a greater load due toincreasing friction and interlocking of the fiber and matrix surfaces.At 400℃, significant changes in the load-displacement pushoutcurves were obeserved. At this elevated temperature, the interfacialfriction produced by radial clamping was significantly reduced dueto the relaxation of residual stresses, and significantly lower forceswere required for pushout. The peak load for pushout of thefatigued samples at 400℃ was almost negligible, indicating thatthe fiber-matrix bond was broken by the fatigue loading.