Effect of multi-interfacial structure on fracture resistance of composite TiSiN/Ag/TiSiN multilayer coating

A composite TiSiN/Ag/TiSiN multilayer coating was deposited on a Ti6Al4V substrate by multi-arc ion plating system. The coating had a special structure with a TiN buffer layer, TiSiN/Ag multilayers that possess alternating TiSiN (45 nm) and Ag (12 nm) layers, and TiSiN coating interlayers of 120 nm thickness for a total thickness of 1.7 μm. The TiSiN layers had a nanocrystalline/amorphous microstructure of nc-TiN, nc-Ag and amorphous Si3N4, with amorphous Si3N4 present around nanocrystal TiN and Ag boundaries, and Ag layers consisting of ductile nanocrystal silver. We have shown that this design of the composite TiSiN/Ag/TiSiN multilayer coating can effectively hinder crack propagation and increase fracture resistance of the coating.