Â鶹ÒùÔº

Navigating the extreme cold of deep space or handling super-chilled liquid fuels here on Earth requires materials that won't break. Most metals become brittle and fracture at such low temperatures. However, new research is pioneering an approach to build metal structures atom by atom to create tough and durable alloys that can withstand such harsh environments.

Traditional strengthening approaches are often not good enough for these applications. For example, a common heat treatment technique called precipitation hardening strengthens metals by creating tiny hard particles within their structure. But in extreme temperatures, the materials can lose their ductility (the ability to bend, stretch or be pulled into a new shape without breaking) and fracture suddenly.

A study in the journal Nature describes a new way to design metal alloys so they stay strong and tough even at super low temperatures. The big idea is to create an alloy with two different types of perfectly arranged atomic structures inside it. These structures are called subnanoscale short-range ordering (SRO), which are tiny islands of organized atoms and nanoscale long-range ordering (NLRO), which are slightly larger.

The researchers created their alloy with a controlled process of heat treating and mechanical shaping, which caused the atomic structures to self-assemble. In other words, scientists created the conditions for the atoms to arrange themselves into the desired structure.

The result was a new cobalt-nickel-vanadium alloy that is exceptionally strong and tough at temperatures as low as -186°C (87 K). It was tested by being pulled and stretched in a lab at extremely low temperatures to see how much stress it could handle.

"Our results highlight the impact of dual co-existing chemical ordering on the mechanical properties of complex alloys and offer guidelines to control these ordering states to enhance their mechanical performance for cryogenic applications," wrote Shan-Tung Tu, one of the study's authors.

With its exceptional strength and durability, especially in extreme cold conditions, the alloy could have numerous practical uses. In space exploration, it could be used to build more durable spacecraft that can handle the extremely low temperatures of deep space. For the energy sector, the alloy could create safer and more reliable infrastructure, such as pipes and tanks for liquefied natural gas.

The researchers also believe that their atomic-level engineering approach could be applied to other types of alloys. This could lead to the development of a whole new generation of materials that can withstand the harshest cold conditions without compromising performance or safety.