Inspired by abalone shells, researcher develops strong, lightweight metal


The United States has abundant reserves of natural gas, which burns cleaner and more efficiently than gasoline, producing about 25% less carbon dioxide. This is better for the environment. Natural gas is also less expensive to extract and process than gasoline, requiring less refining. It is also relatively inexpensive.

For these reasons, motor vehicles that run on natural gas are increasingly popular as alternatives to gasoline vehicles.

Unfortunately, natural gas burns hot, which puts a lot more strain on the metal components of the engine than gasoline.

But a University of Virginia engineer and graduate student developed and patented a new, low-cost alloy that can withstand high heat and perform optimally under the high temperature conditions produced by the combustion of natural gas. The material, which overlays graphene (a promising new semi-metal, stronger than steel and as thin as paper) with nickel powder, maintains its integrity at 1,000 degrees Celsius (much higher than aluminum, at 660 degrees Celsius), making it a perhaps a good choice for natural gas engines.

“The material is lightweight, with an exceptional combination of strength and toughness, which makes it perhaps ideal for critical components in natural gas engines, such as fuel nozzles,” said Chris Li, Professor Rolls- Royce Commonwealth of Mechanical and Aerospace Engineering, who is leading the research. “Engine manufacturers are looking for new materials for alternative fuels, and we’ve created a unique one. “

The lightweight material, called “graphene superalloy,” is lighter than other nickel superalloys (nickel resists high temperatures well) due to the use of the lightweight graphene material. But Li said it is stronger and more durable than other metal mixtures.

“The result is very solid and still light, like the hull. I tell my students that if we pay attention to nature, we can learn from it. “

– Chris Li

Li is inspired by nature to design materials. He said he was very impressed with the shells – the body’s natural armor – of mollusks, such as oysters, clams and abalone, which are a brick-and-mortar-like layer of calcium carbonate taken from sea water.

“Calcium carbonate itself is brittle and weak, but when layered – like brick and mortar – like seashells do, it becomes extremely strong,” he said. “This is what I looked at while we were working on our process of superimposing graphene with nickel; we imitated Mother Nature’s special recipe in building an abalone shell. The result is very solid and still light, like the hull. I tell my students that if we pay attention to nature, we can learn from it. “

Li expects natural gas engines to be widely used over the next five years or so, especially for commercial trucks. He said trucking companies are looking for ways to reduce both their fuel costs and their carbon footprint. The U.S. government seeks to make the nation more energy independent using its own fuel reserves, and the Departments of Energy and Transportation are supporting the search for innovative materials that can accommodate alternative fuels and reduce costs and emissions. greenhouse gases.

UVA research is conducted primarily by Li and her graduate student Yunya Zhang, and builds on UVA’s strengths in materials and engineering technologies for a sustainable and connected society. The work is funded by the National Science Foundation and has been published in scientific progress.


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