Chinese researchers have created a “glass” that can cut diamonds. The transparent, yellow-hued material may find use in many industrial applications and is reportedly 20 to 100 times stronger than standard bulletproof windows.
The research team, led by Professor Tian Yongjun at Yanshan University in Hebei Province, published the results in the blue ribbon science journal, National Science Review.
Yongjun has spent years studying and creating ultra-hard substances. In 2013, the professor and his team made the news when they created a boron nitride crystal twice as strong as a natural diamond.
The new material, named AM-III, is a yellow-tinted, transparent carbon that is incredibly strong, scoring 113 GPa on the Vickers Hardness Test. Typically diamonds will score anywhere between 50 and 70 GPa on the same scale.
While testing just how hard AM-III is, lab technicians cut a deep scratch into the surface of a diamond with relative ease. Not a small feat considering diamonds are one of the most unyielding natural materials and are often used to cut other materials like glass.
Researchers suggest that AM-III will find use in a myriad of industrial applications but, while similar to diamonds, may not find any space in the jeweller’s cabinet as it does not share the same aesthetic quality of diamonds and other gems.
The reason AM-III lends itself to a variety of hi-tech applications is its unique construction. Diamonds and other crystal structures are strong because, at a molecular level, the direction and organisation of the atoms are uniform and synchronised.
Glass, unlike diamonds, has a fragmented and disorganised atomic makeup, making the material inherently brittle and weak. AM-III is described by Tian and his colleagues as glass with crystals inside.
The manufacturing process of AM-III is intensive and requires fullerene, a soft material made of hollow carbon molecules. The team tempered fullerene at high temperatures and crushing pressures, around 1200 degrees Celsius and 25GPa respectively. In the past, scientists have attempted this but have stopped short of the extreme conditions Tian and his team subjected the substance to.
The tempering process, while extreme, was done patiently. It took a reported 12 hours to get the fullerene up to temperature and the cooling period was equally long.
AM-III has a conductivity comparable to silicon making it an excellent candidate for the semiconductor industry. Photoelectric devices and hi-tech weapons that demand pinpoint precision, as well as robustness, also call for properties the material can offer.
While a significant breakthrough, with mass production of the futuristic material still some years away, Tian and the team at Yanshan University are confident the material is an excellent candidate for some very toughest tasks.
https://interestingengineering.com/the-worlds-hardest-glassy-material-is-tougher-than-diamond
