Scientists have developed aluminum alloys with higher strength and superior resistance to hydrogen embrittlement.
A team led by researchers from the Max Planck Institute mixed scandium with aluminum alloys to achieve 40 percent higher strength. Their alloy also offers five times higher resistance to hydrogen embrittlement – while maintaining the same ductility.
Scientists’ innovative approach enables both exceptional strength and superior resistance to hydrogen embrittlement, paving the way for safer and more efficient aluminum components in the hydrogen economy.
Exceptional strength and superior resistance to hydrogen
Researchers revealed that nanoparticles with a shell of particles out of aluminum, magnesium and scandium trap hydrogen and reduce the risk of embrittlement, while nanoparticles of aluminum and scandium increase strength.
Their approach enables both exceptional strength and superior resistance to hydrogen embrittlement, paving the way for safer and more efficient aluminum components in the hydrogen economy.
Researchers used a complex, size-sieved precipitation strategy in scandium-added aluminium-magnesium alloys. Through a two-step heat treatment, the researchers engineered fine Al3Sc nanoprecipitates on which a shell of a highly structurally complex Al3(Mg,Sc)2 forms in-situ.
Method tested across various Al alloy systems
These dual nanoprecipitates are distributed throughout the alloy to serve two key roles: the Al3(Mg,Sc)2 phase traps hydrogen and enhances resistance against hydrogen embrittlement, while the fine Al3Sc particles boost strength, according to researchers.
“Our new design strategy solves this typical trade-off. We no longer have to choose between high strength and hydrogen resistance – this alloy delivers both,” says Baptiste Gault, group leader at the Max Planck Institute for Sustainable Materials.
The resulting material offers a 40 percent increase in strength and a five-fold improvement in hydrogen embrittlement resistance compared to scandium-free alloys.
Researchers underlined that their method was tested across various Al alloy systems, and also demonstrated scalability by using water-cooled copper mould casting and thermomechanical processing methods that align with current industrial standards.
This research paves the way for a new generation of aluminum materials tailored for the demands of a hydrogen-powered future – safe, strong, and ready for industrial use.
Atom probe tomography measurements carried out at the Max Planck Institute for Sustainable Materials were essential in verifying the role of the Al3(Mg,Sc)2 phase in hydrogen trapping at the atomic level, offering insights into how the alloy design works on a fundamental scale. Experiments carried out at the partner institutes included electron microscopy and simulation, according to a press release.
Researchers stressed that their work showcases a possible route to increase hydrogen resistance in high-strength Al alloys and could be readily adapted to large-scale industrial production.
Published in the journal Nature, the study highlights that the hydrogen embrittlement (HE) impairs the durability of aluminium (Al) alloys and hinders their use in a hydrogen economy. Intermetallic compound particles in Al alloys can trap hydrogen and mitigate HE4, but these particles usually form in a low number density compared with conventional strengthening nanoprecipitates.
“Here we report a size-sieved complex precipitation in Sc-added Al–Mg alloys to achieve a high-density dispersion of both fine Al3Sc nanoprecipitates and in situ formed core-shell Al3(Mg, Sc)2/Al3Sc nanophases with high hydrogen-trapping ability,” said researchers in the study.
