グラフェン強化 Al 基ナノ複合材料の機械的特性

Abstract

Basic science of graphene with various superior characteristics has been made clear rapidly on the frontier technology. Nevertheless, various surprising mechanical properties of graphene have been not attracted great attention, such as extreme low density, tensile strength with 100 times stronger than steel by weight, Young's modulus with 1 TPa and more flexible than rubber. We focused on graphene/Al nano composite materials. Since our original successful isolation techniques of creating single layer nanographene sheets from nanographene with a several sheet and uniforming dispersion of nanographene within based materials, we have been challenging in fabrication innovative graphene reinforced Al composite sintered materials with high specific strength and established the fabrication method. It has already been demonstrated that Vickers hardness of graphene/Al composite pellet-formed sintered materials showed the maximum value of 323 Hv, and the density decreased down to 2.45 g/cm3. In this study, we investigated possibility that industrial applications of our graphene/Al nano composite materials. Standard flat-plate type specimens consisted of our graphene/Al nano composite materials were fabricated under the same sintered condition. Bending, tensile mode tests were performed. Elastic and fracture properties were analyzed using four-point bending test apparatus. The results revealed that Young's modulus increased from 40 GPa of sintered Al up to 45 GPa of composite materials. Fracture characteristics showed that the breaking stress of the composite material showed improvement up to 75 %, and the breaking strain of the composite material also increased up to 70 %. These great improvements of mechanical properties can be attributed to reinforcement effect of nanographene. Therefore, graphene/Al nano composite materials give us excellent possibility of the innovative industrial use materials with a promising future.