Mechanical properties and antibacterial behaviors of TaN–(Ag,Cu) nanocomposite thin films after annealing

Abstract

TaN–(Cu,Ag) nanocomposite films were deposited by reactive co-sputtering on Si(001) and M2 tool steels. The films were then annealed using RTA (Rapid Thermal Annealing) at 200°C–400°C to induce the nucleation and growth of metal particles in TaN matrix and on film surface. After deposition, structures, surface morphologies, and mechanical properties were analyzed, the samples were tested for their anti-wear and anti-bacterial behaviors against Gram-negative Escherichia coli. It is found that the antibacterial efficiency against E. coli can be much improved for TaN–(Cu,Ag), comparing with that of TaN–Ag or TaN–Cu films. This could be attributed to large number of surfaced Ag and Cu particles. The tribological properties could also be improved, and are similar to TaN–Ag under a normal load of 5N. In general, the annealing temperature for TaN–(Cu,Ag) can be as low as 200°C. Being annealed at this temperature, the film still shows good antibacterial and anti-wear behaviors.