| Summary: | 碩士 === 國立中興大學 === 材料工程學系所 === 95 === TaN–Ag nanocomposite films were deposited by reactive co-sputtering on Si and tool steel substrates. The films were then annealed using RTA (Rapid Thermal Annealing) at 400 ℃ for 2, 4, 8 minutes respectively to induce the nucleation and growth of Ag particles in TaN matrix and on film surface. C-AFM (Conductive Atomic force Microscopy)、SSPM (Surface Scanning Potential Microscopy) and FESEM (Field-Emission Scanning Electron Microscopy) were applied to examine the Ag nano-particles emerged on the surface of these thin films. The effect of annealing on anti-wear and anti-bacterial properties of these films was studied. A nano-indenter and a pin-on-disc tribometer were used to study the effect of annealing on the films’ mechanical properties. The results reveal that annealing by RTA can cause Ag nano-particles to emerge on the TaN surface. Consequently, the mechanical properties of the films will vary depending on annealing conditions, as well as the anti-bacterial behavior.
The results also show that the size of the surfaced Ag particles may increase with the increase of Ag content and annealing time. The surfaced Ag may act as a type of solid lubricant and causes the decrease of friction coefficient and wear rate. The improvement of mechanical property and the anti-bacterial of the TaN-Ag nanocomposite films is dependent on Ag content and annealing time. For films containing 5.4 at. % Ag, after annealing for 8 minutes, the films’ hardness may increase and reach a 27GPa. This may also results in the decrease of wear rate. In sum, the exposed Ag can act as a type of solid lubricant which may further decrease the friction coefficient and hence the wear rate. Overall, all the annealed TaN-Ag samples can reach >95% antibacterial efficiency in 24 hrs.
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