When developing alloys, researchers often face the challenge of balancing the strength and ductility of materials. Maintaining ductility at low temperatures is particularly difficult, but scientists have managed to find a solution to this problem.

The Problem of Metal Brittleness in Extreme Cold

In space, temperatures can drop as low as -270°C, and on Earth, materials are exposed to intense cooling during the development of quantum technologies, superconductivity, and the storage of biological samples. Under such extreme conditions, most metals retain their strength but become brittle—they can withstand loads but cannot stretch, bend, or change shape.

Ductility is the opposite of brittleness; it is the ability of a material to withstand stretching. For example, gold is highly ductile, which allows it to be rolled into extremely thin sheets and drawn into wire.

A New Approach to Alloy Design

In a recent study, physicists described how they created an alloy based on cobalt, nickel, and vanadium that maintains both strength and ductility at low temperatures. The details of this process were published in the journal Nature.

Traditional methods of strengthening alloys have not yielded significant results for materials used in extremely cold environments. The researchers proposed a new way to design metallic alloys, in which two types of ordered atomic structures form within the material: some arise chemically, while others are created mechanically.

The chemically formed structures are called subnanometer-scale short-range order. They appear as tiny islands of ordered atoms, mainly formed under the influence of temperature. The mechanically induced structure is a nanometer-scale long-range order. The combination of these structures allows atoms within the alloy to self-organize on multiple scales.

Results and Future Applications

As a result of the experiments, the team obtained a cobalt-nickel-vanadium alloy that remains exceptionally strong and tough at temperatures down to -186°C (87 Kelvin). According to the scientists, their development will be especially useful in the aerospace industry and will also be in demand in other fields on Earth.

This new material will enable the creation of more durable spacecraft and reliable infrastructure—such as pipes and tanks for storing liquefied natural gas. Moreover, the approach to material design described in the article can be applied to other types of alloys as well.

"Our results highlight the impact of duplex chemical ordering on the mechanical properties of complex alloys and offer guidance for controlling these states to enhance their characteristics for cryogenic applications," noted one of the study's authors, Shan-Tung Tu.