This image shows the ‘treasure map’ that highlights materials with the best combination of high hardness and fracture toughness. Image: Kvashnin, Skoltech.
This image shows the ‘treasure map’ that highlights materials with the best combination of high hardness and fracture toughness. Image: Kvashnin, Skoltech.

Diamonds aren't just a girl's best friend – they're also crucial components for hard-wearing industrial components, such as the drill bits used to access oil and gas deposits underground. Now, a cost-efficient method for uncovering other suitable materials to do the job is on the way.

Diamond is one of the only materials that is both hard enough and tough enough for the job of constant grinding without significant wear. But diamonds are pricey, which is driving the search for new, less expensive hard and superhard materials. However, the experimental trial-and-error search process is itself expensive.

A simple and reliable way to predict new material properties is needed to facilitate modern technology development. Using a computational algorithm, Russian scientists have now reported just such a predictive tool in a paper in the Journal of Applied Physics.

"Our study outlines a picture that can guide experimentalists, showing them the direction to search for new hard materials," said the study's first author Alexander Kvashnin from the Skolkovo Institute of Science and Technology and Moscow Institute of Physics and Technology.

As fiber optics, with its fast transmission rate, replaced copper wire communications, so are materials scientists looking to find new materials with desirable properties to support modern technology. When it comes to the mining, space and defense industries, it's all about finding materials that don't break easily, and for that, the optimal combination of hardness and fracture toughness is required.

But it's tricky to theoretically predict hardness and fracture toughness. Although lots of predictive models do exist, Kvashnin estimates they are 10–15% off the mark at best.

The Russian team recently developed a computational approach that considers all possible combinations of elements in the periodic table – christened ‘Mendelevian search’, after Dmitri Mendeleev, the Russian chemist who first formulated the periodic table. They then used this algorithm to search for optimal hard and tough materials.

By combining their toughness prediction model with two well-known models for material hardness, the scientists' algorithm learned which regions of chemical space were most promising for creating tough, hard phases that could be easily synthesized.

They plotted the results on a ‘treasure map’ of toughness versus hardness, and were impressed with what they saw. All known hard materials were predicted with more than 90% accuracy. This proved the search's predictive power, and the newly revealed combinations are potential treasures for industry.

Kvashnin explained he is part of an industrial project devoted to developing new materials for drilling bits. Experimentalists on the project are now synthesizing one of these predicted hard materials – tungsten pentaboride (WB5).

"This computational search is a potential way to optimize the search for new materials, much cheaper, faster and quite accurately," said Kvashnin, who hopes this new approach will allow the speedy development of new materials with enhanced properties.

But the scientists aren't stopping there with the theory. They want to use their modern methods and approaches to pin down the general rules for how elements combine in hard and superhard materials to better guide researchers of the future.

This story is adapted from material from the American Institute of Physics, with editorial changes made by Materials Today. The views expressed in this article do not necessarily represent those of Elsevier. Link to original source.