Structure and mechanical properties of diamond-like carbon films with copper functional layer by cathode arc evaporation

► DLC bilayers with Cu functional layer are prepared by double-excitated cathode arc method. ► Cu/DLC bilayer facilitates graphitic rearrangement but DLC/Cu can be against graphitization. ► A three-layer diffusion model is used to describe the diffusion of Cu and C layers. ► Both DLC bilayers showed highly dispersed nano-agglomerates on the surface. ► DLC/Cu bilayer annealed at 100-400 °C showed a higher hardness and lower stress.