MOSCOW, June 25. /TASS/. Chemists from Russia and China have discovered a way of synthesizing a new ultra-hard material which is 50% harder than pobedit (cemented carbide) and which can be used down the road in drilling technologies, machine building, and other fields. This groundbreaking news was announced by the press office of the Skolkovo Institute of Science and Technology (Skoltech).
Ultra-hard substances have a wide range of application covering drilling technologies, machine building, metal processing, and other areas of industry. The hardest known material is the diamond, but by the same token, it is the most expensive. For example, the more affordable pobedit is widely used in drilling heads (a composite material of tungsten carbide with cobalt) and has remained unrivalled for the past 80 years.
The Skoltech researchers led by Professor Artem Oganov and with the aid of an evolutionary algorithm USPEX invented by him predicted a new material which can be synthesized under normal pressure and which can be a successful rival to pobedit if the two most important parameters (hardness and fracture toughness) are considered. Although the new material ranks lower by about 20% in fracture toughness, it is 50% harder than pobedit.
The new material is a previously unknown substance, WB5, which can be easily obtained under normal conditions. According to the authors of the study, the tungsten-boron system was the subject of numerous experimental and theoretical studies, but this compound had not been discovered until now.
"Before we discovered this material, we had studied a large amount of systems, trying to predict stable chemical compounds and calculate their properties. There were many promising substances among them, but they couldn’t compete with pobedit. At some point, I even thought that the pobedit could not be beaten as it held its niche for almost a hundred years and for good reason. But suddenly, we saw a ray of light at the end of the tunnel, and found a unique compound WB5," said Artem Oranov, head of the research team.
The study was carried out within the framework of Gazprom Neft’s major project aimed at creating new materials for drilling technologies. The study’s results were published in the prominent scientific journal The Journal of Physical Chemistry Letters.