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New method developed to produce hardest material

It will remain stable at very high temperatures and ultra-resistant to radioactivity

Water-jet machine at work cutting a steel plate | Shutterstock

Researchers have developed a new procedure for producing materials that require high hardness and strength.

According to the researchers, including those from the University of Seville in Spain, the material is a very hard black solid, which remains stable at very high temperatures, and is ultra-resistant to radioactivity. 

The team has made a variety of the compound boron carbide—one of the hardest synthetic substances known to man—with potential application as a cheap, ultra-resistant material for the design of planes, cars, and other means of transport. It may be used for making parts of blasting nozzles, abrasive water jet cutting, wire-drawing dies and having nuclear applications such as reactor control rods and neutron absorbing shielding.

The study, published in the journal Scientific Reports, noted that boron carbide was a family of ceramic materials represented as BxC. 

The study noted that the boron carbide family consisted of compounds from B4C to B14C, depending on the proportion of B (boron) and C (carbon), and each had different physical properties. 

Boron carbide, used as a powder with various grain sizes or as a ceramic component, is manufactured from the raw materials boron oxide and carbon in an arc furnace at temperatures above 2,400 °C.

Earlier studies had estimated that B6C—with 6 boron atoms to each one of carbon—was theoretically ultra-resistant to radioactivity, but a method to produce it did not exist until now, the researchers said.

In the new study, the researchers used the technique of laser zone floating consisting of fusion by means of the application of intense laser radiation and then rapid solidification.

The researchers found that the boron carbide obtained in this way has a hardness of 52 Gigapascals (GPa), and Young modulus of 600 GPa.

In comparison, the hardness of diamond is around 45 GPa, although it has a Young modulus of 1050 GPa, the researchers said.

"This make phase B6C the hardest material in nature after diamond, and the cubic phase of boron nitride," the researchers wrote in the study. 

(With inputs from PTI)