High quality anti-sticking coating based on multilayer structure

A multilayer Re/Ir coating was deposited on WC substrate by RF magnetron sputtering deposition system. SEM, AFM, XRD, HRTEM, Nano Indenter and contact angle were used to characterize the morphology, micro-structure and anti-sticking property. The results demonstrated that the multilayer Re/Ir coating presented higher anti-sticking property and mechanic performance comparing with the monolayer coatings. The formation of TaC at elevated temperature and coherent boundary between Ta and Ir crystalline were both assumed to impede the further diffusion of C or Co atoms. Moreover, the ordered nanostructure enhanced the bonding between Re and Ir at interface, which made it difficult for Ca, Ba of glass network modifiers elements to penetrate in protective films, and alleviate adhesion of glass at elevated temperature. The motion of edge dislocations and stacking faults were also significantly impeded due to the increase of interfaces and grain boundaries. This restriction probably contributes to improving the mechanical property, which is benefit to the lifetime of mold and the quality of the optical glass product. The wetting angle at high temperature was adopted to evaluate the anti-sticking property of multilayer coating, and shown the coherent results as mentioned before. •Multilayer Re-Ir coating for glass molding was initially deposited and compared with other monolayer coatings.•The promoted mechanical performance is elucidated by the blockage of dislocations motion.•Atoms diffusion resistance by the interfaces were used to explain the improvement of anti-sticking.