Mechanical properties of SiC fibers irradiated by swift heavy ions

Abstract

Mechanical properties and surface features of SiC fibers irradiated with 246.8-MeV Ar ions at different fluences (1.5x1014, 9.0x1014, 1.8x1015, and 2.7x1015 ions/cm2) were investigated using a specific single filament tensile test and a field emission scanning electron microscopy (FE-SEM). Results reveal that carbon concentration on the fiber surface decreases while silicon concentration increases, with increasing ion fluence, accompanied by an adsorption of oxygen. Meanwhile, the diameter of fibers first reduces and then increases, with increasing ion fluence. Moreover, at 2.7x1015 Ar ions/cm2 irradiation, some fibers were fractured. As a result, the mean tensile strength and the average elastic modulus of fibers decrease generally with respect to the ion fluence. The degradation mechanisms of mechanical properties of SiC fibers under irradiation were discussed in detail.