A team of researchers in Hefei, China, have developed what they claim is the strongest pure form of tungsten. The super-strong material has a tensile strength greater than most alloys, making it a prime candidate for many demanding projects, including nuclear reactors, aircraft, satellites and heavy machinery.
Tungsten (or ‘wolfram’), represented by the letter W on the periodic table, is renowned for its strength. After carbon, tungsten has the highest melting point of the known elements (3 400 degrees Celsius) and the highest boiling point (5 930 degrees Celsius).
China currently dominates the tungsten supply, accounting for roughly 80% of all production. Russia and Canada also have significant tungsten reserves but combined only produce roughly 10% of China’s annual output, according to World Atlas. The second-largest economy also has an unmatched appetite for the metal, consuming more tungsten than any other country.
However, the substance’s significant density and strength also make it unyielding and brittle, especially in its raw state.
A collaborated research team which consisted of scientists affiliated with Xi’an Jiaotong University and the Institute of Solid Physics at the Hefei Institutes of Physical Sciences, believes it has developed a novel method to create high-strength, high-ductility tungsten.
Participating research member, Wu Xuebang, described the collaboration’s scientific method in a research paper published by the journal, Acta Materialia.
The team began its objective by low-temperature sintering activated tungsten powders. Sintering is a relatively common method of forming pure tungsten where particles of material are slowly heated and subjected to pressure, eventually fusing at an atomic level, creating a solid structure.
Other methods of forming pure tungsten include forging, extruding and drawing, but powder metallurgy like sintering often offers increased precision and design flexibility.
Wu and his team reported that their novel sintering method created a tungsten material with an ultra-fine grain that maintained its strength but boosted its ductility.
According to the research paper, the tungsten performed outstandingly in the strength and tensile tests it was subjected to. At room temperature, the team recorded a yield strength of 1 302 megapascals (MPa,) outperforming existing tungsten materials. Wu’s team also reported that the material performed well in tensile tests where it also outperformed current tungsten alternatives.
Wu is confident the material will be useful in a variety of industrial applications, including fusion reactors and other high-temperature industries. He added that the method is relatively cost-effective and simple, meaning widespread adoption of the technique may be a possibility.