New Aluminum-Nickel Superalloy Promises 100% Hydrogen Combustion Engines

A groundbreaking superalloy, composed primarily of aluminum and nickel, has been developed by an engineering team at the University of Alberta. This innovative material is specifically designed for high-temperature applications, showcasing remarkable potential in advancing hydrogen combustion engines.

Referred to as a ‘complex concentrated alloy,’ this new superalloy is ideally suited for coating surfaces in gas turbines, power stations, vehicles, and airplane engines. Its introduction marks a significant advancement in material science.

In a paper published in the journal Materials Today, researchers detailed the alloy known as AlCrTiVNi5. This material exhibits exceptional thermomechanical properties, including high stability, low expansion, fracture tolerance, and an advantageous blend of strength and ductility. These characteristics make it particularly suitable for high-heat and high-pressure environments, such as those found in hydrogen engines.

Jing Liu, the senior author of the study, highlighted the alloy’s potential in a media statement. “If you would like to use a 100% hydrogen fuel combustion engine, the flame temperature is extremely high,” Liu explained. “Until now, none of the existing metallic coatings have been able to work in a 100% hydrogen combustion engine.”

Hydrogen combustion involves temperatures ranging from 600 to 1500 degrees Celsius, necessitating that all mechanical components resist both high heat and corrosion from steam. Presently, most hydrogen combustion engines in commercial use operate on a blend of fuels—such as natural gas and hydrogen or diesel and hydrogen. However, as industries increasingly adopt hydrogen as a primary fuel source, the need to prepare for ultra-high temperature conditions in fully hydrogen-fueled engines becomes imperative.

“As we move toward a 100% hydrogen combustion engine, we want to know which alloys can withstand the conditions. None of the existing ones did, but we learned valuable insights from these failures,” Liu noted.

The research team assessed the strengths and weaknesses of each existing commercially available alloy. Using theoretical simulations, they identified potential new combinations that might offer the desired strength and durability.

“We understand how things react when they heat up,” said Hao Zhang, co-author of the study. “So we use these simulations and calculations to understand how the interface between the matter and the environment changes if we change the composition.”

After identifying AlCrTiVNi5, the team subjected the new alloy to the same rigorous high-temperature tests used on existing alloys. While all existing alloys failed after 24 hours or less in the hot, corrosive environment, the new complex concentrated alloy demonstrated remarkable resilience.

“We conducted our experiment in these corrosive environments for up to 100 hours at 900 degrees Celsius, and it survived. That’s a significant improvement,” Zhang stated.

Although the alloy shows great promise for withstanding the heat of a high-percentage hydrogen combustion engine, further studies are necessary before it can be widely adopted.

“This alloy outperforms anything else on the market right now,” Liu said. “It opens the door for new possibilities and will hopefully advance the Canadian hydrogen economy.”