Can the New Super-hard Material Tungsten Boride Replace Tungsten Carbide and Artificial Diamond?

A team of international scientists has reported a new super-hard material that can be used in drilling, machine building and other fields -- a compound based on tungsten boride. It has been proved that this new type of boride has better properties than the widely used cemented tungsten-cobalt composite and synthetic diamond.

Superhard materials are widely used in many fields such as drilling, machinery manufacturing, metal processing, defense industry, and medicine. Although diamonds have the highest hardness, they are relatively expensive materials, and even artificial diamonds can be hard to afford for many applications. So, over the past 80 years, its competitor, the tungsten-cobalt-cemented carbide drill bit has maintained its dominant position in the market with unmatched cost performance.

Tungsten carbide is a black or gray hexagonal crystalline powder that also has a high hardness and is often used as a wear resistant coating for wear parts and a semiconductor film. Previously, due to the difficulty in synthesis, there have been few reports and applications of tungsten boride at home and abroad.

Tungsten carbide materials have been used for decades in the manufacture of drill bits for drilling bits, including drill bits and perforating bullets (a perforating projectile is a drilling tool similar to an armor-piercing projectile). These rigid materials either require higher pressure synthesis or have much lower fracture toughness. In short, they need at least two hard indicators, namely hardness and toughness.

It is well known that hardness and toughness are two parameters of mutual opposition and mutual restriction in metals, The high hardness means the low toughness, then the material will be brittle and fragile. Therefore, finding the balance point between the two parameters is the object that scientists have studied for many years. The scientists used the USPEX evolutionary algorithm to predict a new material –WB5, which can be synthesized at atmospheric pressure and can successfully balance the bit between the two most important parameters - hardness and fracture toughness. New materials are previously unknown compounds and can be easily obtained under normal conditions. The new material is being tested in a large project in Russia and is expected to be used in drilling applications.

Interestingly, the new material discovered by the team was confirmed by the analog synthesis of the supercomputing system. After experimenting with many materials and feeding them into computer systems to predict and calculate their properties, the new material was discovered finally. In conclusion, the tungsten-boron system has been the subject of many experimental and theoretical studies, but their new discovery of this type of tungsten boride has not been discovered until now, which is really surprising. Does it have the conditions to compete with the tungsten-cobalt alloy that has dominated for nearly a century?