Paper MS-ThP1
Development of Dispersed C₆₀-Molecules/Al Composite Materials Using Nanocrystalline Al Powder Synthesized by Pulsed Wire Evaporation Method

Thursday, November 13, 2014, 6:00 pm, Room Hall D

In this study, C₆₀ /Al composite materials were prepared by a usual press sintering method. We must prevent from aggregation of C₆₀ powders in composite materials because the aggregation parts would surely cause a loss of strength of the materials. In order to distribute C₆₀ molecules around Al powders, ultrasonic vibration was applied with isopropyl alcohol as a solvent for 1 h when both powders were mixed before sintering composite materials. The powder for press sintering was prepared to dry in a furnace at about 340 K for 10 minutes. The average diameter of Al powders and the crystal grain size were about 100 nm measured by SEM and several tens of nm estimated by X-ray diffraction method, respectively. The composite materials with uniform dispersion of C₆₀ were fabricated by press sintering process under the condition of the applied pressure of 1 GPa and the temperature of 723K for 4 hour in Ar gas atmosphere. We investigated the optimal condition of the composite materials as changing composition rates from 0 to 5.0 wt.%C₆₀.

In our results, we could not find remarkable aggregated parts of C₆₀ powders mixing powders up to 1.0 wt.%C₆₀ powders by SEM observations, and the microstructures must be considered to dispersion of C₆₀ molecules around Al powders. All specimens sintered were looked like uniform bulk materials. The densities of composite materials decreased according to the increase in the composition rate of C₆₀, and decreased from 2.7×10³ kg/m³ of Al to 2.36 ×10³ kg/m³ of 1.0 wt.%C₆₀. X-ray diffraction method showed only Al crystalline structure for all composite materials and FT-IR analysis clarified the existence of C₆₀ molecules in composite materials. Vickers hardness of Al material showed drastic increase up to 300 Hv in comparison with about 60 Hv of commercial Al materials due to nanocrystallization effect. The composite material with 1.0 wt.%C₆₀ showed the maximum value of 340 Hv. The specific strength of 1.0wt.%C₆₀ was increased up to 5.4 times comparing with those of industrially Al materials. This maximum specific strength of this study clarified surprisingly enhancement of over 3 times in comparison with that of commercial Mg alloys. Therefore, dispersed C₆₀-molecules/Al-matrix composite materials with nanocrystalline powder give us dreams of development for innovative high specific strength materials.