appConfigEntityId

bodyType

customContents

entityId

entityUuid

isVideo

articlePageQuery

article

articleSchemaContent

content

hooksArticlePageAdvertisementConfigArticle

hooksArticlePageFloatingButtonConfigArticle

appConfig

filter

json

liveArticle

Zhang Tong

A team of Chinese scientists says it has developed an alloy that retains strength at ultra-high temperatures using tantalum – a very hard and flexible metal.
For applications in aerospace, hypersonic vehicles and nuclear reactors, materials must endure both extreme heat and heavy loads. But most metals fail above 2,000 degrees Celsius (3,632 degrees Fahrenheit) – they either melt or soften to a putty-like consistency.
New research is challenging that limit.
According to a paper published last month in Nature, a research team led by Sun Jun at Xian Jiaotong University has developed an alloy that maintains exceptional load-bearing performance at temperatures up to 2,400 degrees.
For most metals, once the temperature reaches about 60 per cent of their melting point, their internal structure changes rapidly and their strength drops. For example, the nickel-based single-crystal superalloys widely used in aeroplane engines cannot cross the 2,000-degree threshold.
The team’s work focuses on a tantalum alloy. Tantalum melts at nearly 3,000 degrees and alloys made using the metal are among the few materials that can carry loads above 2,000 degrees.


Tantalum alloys are usually strengthened by a technique called oxide dispersion – tiny ceramic particles are spread evenly through the metal to act as an internal scaffold.
But above 2,000 degrees, those particles start to dissolve and the alloy becomes brittle.
In the 1960s, Nasa turned to carbides – which are strengthened with carbon – because of their high melting point compared with oxides. But the T‑222 alloy Nasa developed, which was once mass-produced, has a tensile strength below 100 megapascals (MPa) at 1,926 degrees. That is roughly equivalent to the strength of a piece of wood with a cross‑sectional area of 1 sq cm (0.155 square inches) – it would snap under a load of just 1 tonne (0.98 ton), whereas ordinary structural steel at room temperature can handle 4 tonnes.
To boost performance, the Xian Jiaotong team devised a new process they called “boron-intervened in situ oxidation.”
They added trace amounts of hafnium boride to the tantalum, which captured oxygen to form stable hafnium oxide particles and released boron atoms that spread through the tantalum. These boron atoms then coated the hafnium oxide nanoparticles like a protective shell, stopping them from dissolving at high temperatures.
The resulting alloy shows remarkable mechanical properties. At room temperature, it has a tensile strength above 800 MPa and can stretch by 35 per cent, making it easy to shape and process.


At 2,000 and 2,400 degrees, it maintains tensile yield strengths of 200 MPa and 100 MPa respectively – outperforming all other known alloys. Tests also indicate that it is much more durable than traditional alternatives.
“This new tantalum alloy delivers double the tensile yield strength at 2,000 degrees compared with conventional tantalum alloys. Moreover, when bearing an identical load of 100 MPa, its temperature ceiling is raised by around 500 degrees over existing tantalum-based materials,” Sun told China’s state news agency Xinhua.
The alloy’s unique heat resistance and flexibility open up new engineering possibilities in extreme environments.
The authors also showed their boron process translates effectively across different metals, including other tantalum-based alloys and niobium-tungsten alloys, suggesting broad applicability for the next generation of ultra-high-temperature structural materials.


T. rex was warm-blooded and had body temperature close to ours, study finds

China uses 100,000 home-grown AI chips to build leading weather forecast system

Geologists find unexpectedly large water sources in Xinjiang beneath China’s largest desert

Chinese scientists build world’s smallest CT scanner, weighing just 6kg

Science

How Chinese scientists created an alloy that can survive 2,400 degrees Celsius

The tantalum alloy’s unique heat resistance and flexibility open up new engineering possibilities in extreme environments. Photo: Getty Images

China’s unique high-orbit satellite is using a rare metal the US struggles to obtain

The satellite can monitor a third of the Earth’s surface. Photo: China Academy of Space Technology 

Each high-power amplifier can generate 800 watts. Photo: Journal of Microwaves

Why the US-China space race could come down to a thin metal cap

A Long March-10B carrier rocket blasts off from a spacecraft launch site in Wenchang in China's southern Hainan province on Friday. Photo: Xinhua

A proprietary, ultra-low-temperature integral forming process for tank domes slashes production time from more than a week to just a few hours. Photo: CCTV

Why China is looking to coal waste as a source of critical metals

Amid a global energy shortage, coal piles sit near a chemical plant in Datong, as China turns coal into critical metals. Photo: AP 

Could China’s metal-like composite make drones, planes and rockets 26% stronger?

Researchers say improved joint strength addresses a long-standing weakness in composite materials, such as those used for uncrewed aerial vehicles. Photo: Getty Images

At US$1,455 per ounce, China’s e-waste gold recovery is world’s most efficient

Chinese scientists have found a way to harvest gold from electronic waste in under 20 minutes and at a cost less than a third of the present market price. Photo: Shutterstock

Central processing units found in computers contain precious metals including gold that can be harvested in under 20 minutes using a new technique. Photo: Shutterstock

News

China

The tantalum alloy developed at Xian Jiaotong University could be used in aerospace, hypersonic vehicles and nuclear reactors


The tantalum alloy developed at Xian Jiaotong University could be used in aerospace, hypersonic vehicles and nuclear reactors.


Xian Jiaotong University

How Chinese scientists created an alloy that can survive 2,400 degrees Celsius

.css-1c6uqr6{color:inherit;font-weight:inherit;font-size:inherit;font-family:inherit;line-height:inherit;overflow-wrap:break-word;}The tantalum alloy developed at Xian Jiaotong University could be used in aerospace, hypersonic vehicles and nuclear reactors

The tantalum alloy developed at Xian Jiaotong University could be used in aerospace, hypersonic vehicles and nuclear reactors