Surface patterns formation by ion irradiation of PAN based carbon fibers

Surface patterns on PAN based carbon fibers under 3 and 30 keV He+ and 30 keV Ar+ ions irradiation were experimentally studied. It has been found that the depth distributions v(x) of the number of displacements per atom (dpa) have a strong effect on the surface patterns on PAN-based carbon fibers. For not steady state profiles v(x), a ridge-like structure oriented along the fibers is formed on the surface. At sufficiently high irradiation fluences with a steady-state profile v(x), a corrugated structure is formed with corrugations transverse to the fiber axis. The corrugation effect is explained by twinning during plastic deformation of fiber shell crystallites caused by radiation-induced dimensional changes and mechanical stresses.

Automated summary

The experimental study investigated the surface patterns on PAN-based carbon fibers under 3 and 30 keV He+ and 30 keV Ar+ ions irradiation. It was found that the depth distributions of the number of displacements per atom have a significant impact on the surface patterns. Different surface structures were observed depending on whether the depth distribution profiles were steady-state or not, with ridge-like structures forming when profiles were not steady-state and corrugated structures forming at high irradiation fluences with steady-state profiles. The corrugation effect was attributed to twinning during plastic deformation of fiber shell crystallites caused by radiation-induced dimensional changes and mechanical stresses.