Cubic boron nitride nanopowder for metal cutting tools

Cubic boron nitride is a superhard material that is only 20 to 40 percent harder than diamond. Although second only to diamond in hardness, CNB surpasses gemstones in other important areas: The composite material does not react to carbon, making it possible to process steel, which accounts for 90 percent of mechanical engineering materials. By contrast, diamond reacts with one of its constituents, carbon, limiting its usefulness. Instruments made from nano-CNBs can cut metals that were previously uncut.