Rhenium Diboride

Rhenium diboride (ReB2) is a synthetic superhard material. It was first synthesized in 1962 and re-emerged recently due to hopes of achieving high hardness comparable to that of diamond. However, the reported ultrahigh hardness has not been confirmed.

The production method of this material does not involve high pressures as with other hard synthetic materials, such as cubic boron nitride, which makes production cheap. However, rhenium itself is an expensive metal.

The compound is formed from a mixture of rhenium, noted for its resistance to high pressure, and boron, which forms short, strong covalent bonds with rhenium.

Read more about Rhenium Diboride:  Synthesis, Properties