Research on friction layer is needed for mechanical systems and assemblies in order to control failure and wear of contacting materials. This study investigates the formation of friction layer of Ni3Al matrix composites (NMCs) with multi-layer graphene (MLG) under different contact loads. The results show that, under 15 N condition, the friction layer with the ultrafine grain and nanocrystalline structure mainly consists of the thin debris re-embedded layer (DREL) and the matrix refinement layer (MRL). The build up of the DREL is a dynamic equilibrium recovery process. The severe plastic deformation induces the dislocations and twinning, as well as misorientation boundaries, resulting in the formation of the stress dissipative structure in MRL. The low friction coefficient (0.27-0.30) and wear rate (1.2 -1.6 x 10(-5) mm(3)N(-1) m(-1)) of NMCs at 15 N load are attributed to the formation of friction layer with micro- and nano-structure during sliding friction. (C) 2014 Elsevier B.V. All rights reserved.