Compared with gasoline, natural gas burns cleaner and more efficient, produces about 25% less carbon dioxide, and the cost of refining and processing is also relatively low. Therefore, natural gas-powered vehicles are increasingly concerned. However, due to the high combustion temperature of natural gas, the requirements for metal engine components are also much higher.
Researchers at the University of Virginia in the United States have developed a new metal matrix composite material by combining nickel powder and graphene flakes. This new metal matrix composite material is called "graphene superalloy" (graphene superalloy). Because of the use of lightweight graphene materials, it is lighter than other nickel-based superalloys and is more durable. The professor who led the study 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. Using a similar aragonite structure, the strength of graphene nickel-based composites has increased by 73%, and the toughness has been reduced by only 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 in achieving this goal is that graphene may cost hundreds of dollars per gram. The main researcher 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.