By producing diamond and cubic boron nitride thin films from a gas mixture, scientists from Tomsk Polytechnic University (TPU) are creating coverings for next-generation cutting tools that are not only durable but also suitable for the treatment of most materials.
Diamond coatings, thanks to their hardness, have been widely used in the manufacture of cutting tools. They’re appropriate for the treatment of some metal alloys, ceramics, and carbon composites but ineffective for iron and steel because at high temperatures carbon interacts with these metals and gradually collapses.
To resolve this problem, TPU scientists proposed to develop a composite coating based on diamond and cubic boron nitride. It is the hardest known material. Cubic boron nitride is not destroyed by contact with iron and steel, which makes a tool almost "invulnerable."
"Nobody has synthesized cubic boron nitride coatings in the form of polycrystalline carbon yet. We want to use the crystal lattice proximity of the substance and diamond. This similarity allows growing cubic boron nitride crystals on diamond crystals,” explains Stepan Linnik, a research engineer from the TPU Institute of High Technology Physics laboratory. “Our coating that integrates the properties of diamond and nitride coatings will be applicable to most metals."
