Physical Characterizations of Ni-Plated Carbon Fibers after Controlled Thermal Treatments

Abstract

Surface modifications of carbon fibers (CFs) were conducted by electroless Ni depositions. After annealing in air at 300 degrees C, we fabricated a composite in NiO/Ni/CFs configuration. The samples revealed reasonable surface uniformities without defects at the interfaces. Values for the electrical resistivity indicated a steady increase with annealing time, reaching a plateau after 72h. Results on the tensile stress exhibited a marked reduction once the NiO was formed. A thermal treatment at 700 degrees C for 48 h in air allowed complete removal of the CFs, forming NiO hollow tubes with an inner diameter of 6.50 mu m. Subsequently, they were transformed into Ni hollow tubes with a reduced inner diameter of 5.53 mu m under a hydrogen treatment at 400 degrees C for 3 h. The NiO and Ni tubes demonstrated impressive structural integrities with considerable mechanical strengths. (C) 2009 The Japan Society of Applied Physics