High Strengthening of PAN-based Carbon Fiber by Imposing of a High Magnetic Field in Graphitization Process

Abstract

A high static magnetic field was imposed on PAN-based carbon fibers in the graphitization process. Oxidized fibers were graphitized in the magnetic field of 12 T and at the temperature of 2, 273 K. Samples were made under the magnetic fields perpendicular to fiber axis and parallel to it. The latter treatment has improved the tensile strength more than the former does. In the both samples the increase of the tensile strength more than 30% has been achieved by imposing the magnetic field. The reason of improvement of the tensile strength is discussed from the view points of magnetic energies difference due to the magnetic anisotropy of a six carbocyclic ring and of flaws on a fiber.