The morphology and structure of one-dimensional carbon–carbon composite under high-fluence ion irradiation

Erosion of carbon fiber composites under high-fluence heavy ion irradiation

“…At temperature T < T a the diffraction patterns exhibited an amorphous halo. At elevated temperatures for KUP-VM the diffraction patterns obtained in the measurements along and across carbon fibers virtually do not differ from one another and are a system of three slightly smeared rings typical for isotropic polycrystalline graphites, as in the case of 30 keV N þ 2 irradiation [8]. One should note that in the case of Desna 4, due to its specific architecture, both the fibers recumbent on the sample surface and the fibers arranged perpendicular to the sample surface (i.e., the butt-ends of the fibers) are simultaneously irradiated.…”

“…The analysis of KUP-VM and Desna 4 surface topography using SEM and optical microscopy has shown that, as in the case of 30 keV N þ 2 -KUP-VM [7,8], Ar + irradiation results at relatively low temperatures (T < T a ) to the retention of one-dimensional fiber morphology; although the fibers etching and formation of the trough-like longitudinal cavities and hillocks has been observed, see Fig. 2a and c. Some nanoneedles are created on the cavities edges of the eroded fibers.…”

“…Namely, the crimping was observed for 30 keV N + irradiation of PAN fibers. It should be noted that irradiation in [7,8,16] was made by nitrogen ions which can form a C-N chemical compound. Argon ion bombardment used in the present study allow us to find that the cause of crimping is a pure physical ion-induced process.…”

“…For comparison the samples of polycrystalline graphite MPG-8 were also irradiated. The experimental procedure is described elsewhere [7,8]. Irradiation was produced by 30 keV Ar + ions.…”

“…Investigations of the structure and morphology of the ion-induced surface layer of one-dimensional CFC KUP-VM under high 30 keV N þ 2 ion irradiation showed that irradiation results in a loss of anisotropy of the KUP-VM surface layer structure. This is because of amorphization at room temperature or recrystallization at a temperature higher than a dynamic annealing temperature T a when fiber crimping had been observed [7,8].…”