Mechanical properties of SiC fibers irradiated by swift heavy ions

[摘要] 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.

[发布机构] Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, China^1;University of Chinese Academy of Sciences, Beijing, China^2;Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, China^3

[效力级别] 材料工程

[关键词] Carbon concentrations;Degradation mechanism;Fiber surface;Field emission scanning electron microscopy;Silicon concentration;Single filaments;Surface feature;Swift heavy ions