New Copper Alloy Could Provide Breakthrough in Durability for Military Systems

June 11, 2025

An atomic-scale close-up of the copper-lithium particle, one of many embedded in the microstructure of the nanocrystalline copper-tantalum-lithium alloy. The blue features represent the lithium atoms; the yellow features represent the tantalum atoms encasing the lithium atoms and the orange features represent the surrounding copper matrix. (Image: Lehigh University)

U.S. Army researchers, in collaboration with academic partners, invented a stronger copper that could help redefine the use of high-temperature materials in aerospace and defense applications, thanks to its ability to endure unprecedented temperature and pressure extremes.

Extreme materials experts at the U.S. Army Combat Capabilities Development Command, known as DEVCOM, Army Research Laboratory built on a decade of scientific success to develop a new way to create alloys that enable Army-relevant properties that were previously unachievable. An alloy is a combination of a metal with other metals or nonmetals.

Along with researchers at Arizona State University, Lehigh University and Louisiana State University, ARL produced a nanocrystalline copper-tantalum-lithium alloy that can conduct electricity and heat like copper while demonstrating incredible strength and durability even at extremely high temperatures. Copper on its own has excellent heat and electricity conduction but doesn’t do well under extreme conditions needed in operational environments.

Their research, previously published in the journal Science, introduces a Cu-Ta-Li (Copper-Tantalum-Lithium) alloy with exceptional thermal stability and mechanical strength, making it one of the most resilient copper-based materials ever created.

The breakthrough comes from the formation of Cu₃Li precipitates, stabilized by a Ta-rich atomic bilayer complexion, a concept pioneered by the Lehigh researchers . Unlike typical grain boundaries that migrate over time at high temperatures, this complexion acts as a structural stabilizer, maintaining the nanocrystalline structure, preventing grain growth and dramatically improving high-temperature performance.

The alloy holds its shape under extreme, long-term thermal exposure and mechanical stress, resisting deformation even near its melting point, noted Patrick Cantwell, a research scientist at Lehigh University and co-author of the study.

By merging the high-temperature resilience of nickel-based superalloys with copper — which is known for exceptional conductivity — the material paves the way for next-generation applications, including heat exchangers, advanced propulsion systems and thermal management solutions for cutting-edge missile and hypersonic technologies.

“The Army’s new copper alloy represents a significant advancement in materials, promising lighter, more durable equipment that can perform reliably in extreme conditions,” said Lt. Col. Erik Kifune, ARL S&T Portfolio Manager. “This material will be instrumental in advancing the next generation of Army weapons making the future force more lethal and better protected.”

Tests conducted by the research team showed that the new alloy can withstand stress, both at room temperature and at extreme conditions, several times better than some of the best high-temperature commercial copper alloys.

The U.S. Army began licensing this technology to industry partners to accelerate its transition from fundamental research to real-world Army systems, helping to transform the Army to ensure war-winning future readiness.

“These findings could lead to armor that can absorb sudden and intense impacts without weakening, enabling longer-lasting, more reliable protection,” said Dr. Kristopher Darling, Army Materials Engineer at ARL. “This material could also play a critical role in the next generation of modular reactors — set to power the future battlefield — thanks to its unique combination of resistance to high-temperature creep, immunity to radiation damage and excellent thermal and electrical conductivity. The range of potential applications is staggering.”

Nanocrystalline copper alloys first attracted attention as a sturdier alternative to regular copper metal. Yet despite years of research demonstrating higher mechanical strength, they exhibited such structural instability at elevated temperatures that many saw them as too difficult to process and use.

In 2011, however, Army researchers demonstrated the unparalleled thermal stability and high temperature resilience of a nanocrystalline copper alloy augmented by tantalum — a phenomenon never seen before in nanocrystalline metals.

ARL’s continued research investment in nanocrystalline copper-tantalum alloys unveiled a new strategy in creating alloys that can simultaneously absorb tremendous impact and withstand extremely high temperatures, all without even a hint of deformation.

The research exemplifies how controlled nano-structuring can engineer resilience, said Darling.

“Much like oil and water, copper and tantalum do not mix well together, and we realized that forcing copper and tantalum into forming a solid solution might kinetically trap the system in an intermediate state and effectively freeze the microstructure,” he said. “As materials are increasingly expected to endure extreme mechanical, thermal and radiative conditions in the future operating environment, [this alloy] stands as both a legacy and a blueprint for the future of high-performance metallic systems.”

According to Darling, the new copper-tantalum-lithium alloy sets a new standard for material performance in extreme environments, because it doesn’t compromise in either strength, conductivity or durability like other commercial copper alloys.

“If these design principles can be successfully translated to other base metals, such as nickel, the implications could be even more profound,” Darling said. “A nanostructured nickel-based alloy with superior mechanical and thermal properties would redefine the performance limits of turbine engines, allowing them to operate under more extreme conditions. This would be a game-changer for sustained supersonic or hypersonic flight, making propulsion systems more efficient, more durable, and less reliant on complex cooling schemes.”

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