Harder Than Diamond: Cubic Boron Nitride Is the New Ultra-Hard Substance

Benjamin Reeves   |  January 29 2013 3:16 EST

It's been an given for centuries that nothing is harder than diamond, but it seems that even diamonds must lose their crown eventually. Scientists at a consortium of universities have succeeded in creating a substance harder than diamond, nanotwinned cubic boron nitride.

Researchers from the University of Chicago, University of New Mexico, Yanshan University, Jilin University and the Hebei University of Technology succeeded in synthesizing the new substance. The nanotwinned cubic boron nitride has a Vickers score, the scientific measure of hardness, of 108, compared to 100 for synthetic diamond, according to Wired.com. However, scientists aren't completely sure exactly how hard the new substance is because the only way to measure hardness is to try and dent it with something even harder.

Most super-hard materials, like diamond, are based on the element carbon. Cubic boron nitride, however, is made up of a “latticework of boron and nitrogen atoms,” according to Scientific American. Moreover, the nanotwinned structure of the new material makes it incredibly strong. Basically, the crystalline structures of the new material are interlocked together, similar to the way anti-roll bars stiffen the chassis of a car.

The material possesses “onion-like nested structures with intrinsically puckered [...] layers and numerous stacking faults,” according to the research abstract published in the journal Nature's Jan. 17 issue.

The newfound material could improve efficiency and potentially cut costs for industries using heavy machinery. For instance, enhancing the durability of tools like drill bits and saw blades with cubic boron nitride would make them more efficient and decrease the frequency of repairs.

Compounds featuring various crystalline forms of boron nitride have been at the center of several recent advances. Besides the new ultra-hard material, researchers at Rice University say that they have succeeded in bonding another form, hexagonal boron nitride, with graphene to create a nano-scale insulated conductor, according to UPI Monday.

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(Diamond, pictured, courtesy Wikimedia Commons.)