Paper TF-ThP11
Development of Dispersed C60/TiAlN Nano-Composite Thin Films with Superior Mechanical Properties

Thursday, October 22, 2015, 6:00 pm, Room Hall 3

We have succeeded in the development of innovative dispersed C₆₀ molecule nano-composite Al and TiN thin films with great high hardness and excellent tribological properties. Fabrication method of their composite films has been used by our original unique vacuum evaporation method with both RF magnetron sputtering source and heat evaporator source. Nano-indentation hardness of 1.0 wt.%C₆₀/Al nano-composite thin film showed increased up to 3 times larger than that of Al film. And 2.0 wt.%C60/TiN nano-composite thin film, both nano-indentation hardness and tribological properties increased up to 30 % larger than those of a conventional TiN thin film. These results clearly indicated that dispersion of C₆₀ molecules in the conventional films contributed improvement in mechanical properties.

In our study, we challenged to apply the established techniques to fabricate nano-composite materials using C₆₀ to TiAlN, which is harder than TiN. Development of the synthesis method of C₆₀/TiAlN nano-composite thin films with the excellent mechanical properties more than those of TiN nano-composite must give effective industrial contributions. C₆₀/TiAlN nano-composite thin films with constant thickness 200 nm were deposited on Si(100) water-cooled substrates using by the same method with both Ti and Al sputtering targets for 30 minutes. The concentrations C₆₀ molecule powder were changed in the range from 0.5 to 40 wt.%, and the evaporation temperature was controlled in the range of 523-723 K. The structure analyses of all nano-composite thin films showed that XRD patterns indicated only TiAlN crystalline structure and absorption peaks estimated by FT-IR also corresponded to those of C₆₀ molecule. From these results, the microstructures of C₆₀/TiAlN nano-composite thin films were confirmed to consist of both C₆₀ molecule and TiAlN crystalline metallic compound. Nano-indentation hardness made clear that the hardness of the composite films of 2.0 wt.%C₆₀/TiAlN showed the maximum hardness of 20 GPa and this value was increased up to 20 % larger than that of TiAlN thin film. Furthermore, tribological properties were also increased up to 20 % larger than that of TiAlN.

On the basis of remarkable results of the previous researches and the present results, it clearly indicates that C₆₀ nano-composite is extremely effective in great mechanical properties improvement to dispersed C₆₀ uniformly in matrix conventional thin films. Therefore, this study let us know one of bright future view of development of the innovative great hard composite thin films using by C₆₀ molecules.