One of the characteristics of graphene that is often mentioned but seldom exploited is its strength compared to other materials. Its tensile strength has been measured at 130 GigaPascals, making it 200 times as strong as steel.
Now researchers at the Korean Advanced Institute of Science and Technology (KAIST) have put graphene’s tensile strength to work by using it in a composite consisting of copper and nickel. The graphene makes the copper 500 times as strong as it would be on its own and the nickel 180 times as strong.
This work is a significant breakthrough, since previous attempts to use graphene in a metal composite have not resulted in increased strength in the doped material. In the KAIST research, which was published in the journal Nature Communications ("Strengthening effect of single-atomic-layer graphene in metal–graphene nanolayered composites"), chemical vapor deposition (CVD) was used to grow a single layer of graphene on a metallic deposited substrate, and then another metal layer was deposited. These steps were repeated, resulting in a multilayer metal-graphene composite material.
According to the researchers, this work represents the first time a metal-graphene multilayer composite material has been successfully produced that exploits graphene's extraordinary strength.
“The result is astounding as 0.00004% in weight of graphene increased the strength of the materials by hundreds of times,” said Professor Seung Min Han in a press release. “Improvements based on this success, especially enabling mass production with roll-to-roll process or metal sintering process, in the production of automobile and spacecraft lightweight, ultra-high strength parts may become possible.”
If the process can be duplicated on an industrial scale, it would indeed be a possible way to make automobiles and aircraft lighter and therefore more fuel efficient. We’ve already seen how a nanocoating on aircraft that reduces fuel consumption by just 2 percent resulted in a whopping US $22 million in savings per year for just one airline.
This graphene-metal composite, according to Han, can also be used as a coating in nuclear reactor construction or other structural applications.