The effect of annealing on the properties of copper-coated carbon fiber

In this paper, we prepared copper-coated carbon fibers (CFs) by electroplating and studied the effect of annealing temperature on the electrical conductivity and mechanical properties of these fibers. The results showed that the defects of the copper layer were reduced after annealing. The XRD peak intensity and grain size of the copper layer increased significantly with the increase in annealing temperature, indicating that annealing can effectively increase crystallinity and reduce the presence of grain boundaries. After annealing for 20 min, the conductivity of the copper-coated CFs increased by 78 times, and the mechanical properties also improved. The effect of grain boundaries on the electronic transport properties of copper was studied using the density functional tight-binding method in combination with the non-equilibrium Green's function method. According to the results, the existence of grain boundaries reduces the transmission probability of electrons and current passing through the system, as well as the uniformity of the atomic potential distribution in the central region of the structure, which hinders the transmission of electrons.