Effect of cluster interface structure on the spontaneous escape behavior of silver in ion plating coatings and its inhibition mechanism

Highlights: • The escape rate of silver from TiN film is lower than that from the carbon film. • The permanent retention of large amount of silver can be achieved in TiN films. • The dendritic structure of the TiN cluster interfaces blocks the escape of silver. • The electrical conductivity of the film increases with the content of silver. - Abstract: In order to study the spontaneous escape behavior of silver in ion plating coatings and its inhibition mechanism, a series of silver-doped titanium nitride coatings were prepared by magnetron sputtering. The effect of cluster interface structure on the spontaneous escape behavior of silver in ion plating coatings were observed, and various thicknesses of homogenous silver-free barrier layers were explored to achieve the permanent retention of silver. Results showed that for silver-doped titanium nitride coatings prepared with the silver target current increased from 0.01 A to 0.2 A, more spontaneously escaped silver particles were observed at the cluster interface of the coating and were far from being crystallized into a layered structure. Approximately 500 nm pure titanium nitride surface cover could achieve the permanent retention of silver in titanium nitride coatings with a high dopant content of silver. The cluster interfaces of the titanium nitride coating interdigitated with each other to form a dendritic network structure. The interdigitated dendritic network structure blocked the spontaneous escape of silver and achieved the permanent retention of silver in the titanium nitride coating.