Ion-Induced Corrugation and Surface Erosion of PAN-Based Carbon Fiber
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NCED CONSTRUCTION MATERIALS
Ion-Induced Corrugation and Surface Erosion of PAN-Based Carbon Fiber V. A. Anikina, A. M. Borisova,*, A. V. Makuninb, E. S. Mashkovab, and M. A. Ovchinnikova,b aMoscow bSkobeltsyn
Aviation Institute (National Research University), Moscow, 125993 Russia Institute of Nuclear Physics, Moscow State University, Moscow, 119991 Russia *e-mail: [email protected] Received July 4, 2018; revised July 4, 2018; accepted August 4, 2018
Abstract—The regularities of ion-induced corrugation of a VMN-4 carbon-fiber shell of the KUP-VM unidirectional composite under high-fluence irradiation with Ar+ ions at energies of 20 and 30 keV have been experimentally studied in the range from room temperature to 600°C. A developed submicron corrugated structure of the carbon fiber surface at an ion path length of 20–40 nm in graphite is registered starting from temperatures around 200°C. The corrugation period is a few hundred nanometers, weakly depends on the temperature of the irradiated carbon fiber, and decreases with a decrease in the ion energy or an increase in the incidence angle of the ion beam on the cylindrical fiber surface. The temperature of an irradiated fiber has a strong effect on the geometry and the fraction of corrugations in the fiber surface part irradiated with ions at normal incidence. For an ion energy of 20 keV in the temperature range of 350–500°C, the apical part of the fiber is similar to the initial surface. A stronger effect of corrugation reduction for an argon-ion beam energy of 20 keV in comparison with an irradiation energy of 30 keV is explained by the competition between the processes of ion-induced corrugation under plastic deformation of the modified layer and the surface erosion at sputtering, which leads to the smoothing of the surface. Keywords: carbon fiber, carbon-carbon composite, ion-induced corrugation, surface erosion, sputtering, plastic deformation DOI: 10.1134/S1063778818110029
INTRODUCTION Carbon-carbon composite materials reinforced with carbon fibers on the basis of polyacrylonitrile (PAN) are considered as priority structural materials for nuclear reactors, plasma devices, and aerospace equipment [1]. As regards the structure, the fibers consist of a core of turbostratic structure and a highly perfect textured graphite shell with the dominant direction of the c axis along the fiber radius. It is known that the radiation damage on the physical properties of graphite materials strongly depends on the irradiation temperature [1–3]. Thus, the neutron irradiation of carbon fibers leads to a complicated dependence of their dimensional changes on the irradiation temperature [1]. High-fluence ion irradiation of composite materials reinforced with carbon fibers can lead both to structural changes and to significant changes in the fiber shell morphology [4–6]. At the same time, amorphization and recrystallization processes and development of specific surface morphology, in particular, corrugation of the fiber, can take place depending on the irradiation temperatu
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