▎ 摘　　要

In this work friction characteristics of polycrystalline graphene grown on the metallic matrix from the liquid phase via new metallurgical method were investigated using atomic force microscopy under the range of applied normal loads. Polycrystalline graphene films were transferred onto silicon oxide using a modified polymer supported transfer process. Lateral force microscopy mode with both silicon and diamond-like carbon coated probes was used to measure the friction properties. Ogletree method was employed in order to calibrate the lateral force and estimate the average friction coefficient of polycrystalline graphene. As a comparison the friction of SiO2 surface, commercially available CVD grown graphene monolayers transferred onto SiO2 as well as highly oriented pyrolytic graphite were also measured under the same experimental conditions. (C) 2014 Elsevier Ltd. All rights reserved.