Researchers at the University of Virginia developed a new type of high-temperature resistant low-cost alloy by combining nickel powder and graphene flakes, and applied for a patent. This new metal matrix composite material can maintain integrity at 1000 degrees Celsius, or it will become a good choice for natural gas engine materials.
Such lightweight materials are called "graphene superalloys" (graphene superalloy). Because of the use of lightweight graphene materials, it is lighter than other nickel superalloys, but stronger and more durable than other metal mixtures. Chris Li, a professor at the School of Mechanical and Aerospace Engineering who led the research, said: "This material is very light, and the perfect combination of strength and toughness may make it an ideal material for key components such as fuel nozzles for natural gas engines."
Researchers draw inspiration from nature when designing materials, such as mother-of-pearl shells. "They have a layer-by-layer structure." Mother-of-pearl consists of hexagonal aragonite flakes, whose strength and toughness are extremely rare among engineering materials. In the manufacture of most composite materials, the combination of the two alloys will cause most composite materials to lose ductility or toughness. However, with aragonite-like structures, the strength of graphene and nickel composites can be increased by 73%, and the tensile capacity is only reduced by 28%. This composite material can maintain high hardness even at a high temperature of 1000 degrees Celsius.
Replacing battery and engine materials with graphene reinforced materials helps reduce energy consumption. The challenge to achieve this goal is that graphene may cost hundreds of dollars per gram. Lead researcher Zhang said: "When applied to vehicles, cost needs to be considered. Cost is always the first. If you can not reduce the cost of graphene, you cannot use graphene in a large number of cars.
Researchers expect that natural gas engines will be widely used in the next five years or so, especially for commercial trucks. Trucking companies are looking for ways to reduce fuel costs and carbon emissions. Currently, the US Department of Energy and Transportation is supporting research on innovative materials to adapt to alternative fuels and reduce costs and greenhouse gas emissions. On a smaller, lower-cost scale, graphene can be used to improve common technology. For example, it can be used to manufacture flexible screens, and even flexible batteries for mobile phones, and may also be used for 3D printing.