hardmaterials

Hardmaterials refers to materials exhibiting exceptionally high resistance to permanent deformation and scratching, typically assessed by hardness tests such as Vickers, Knoop, or Rockwell. In industry, materials with high hardness are prized for wear resistance, cutting performance, and longevity in abrasive environments.

Diamond is the most well-known hard material, with a Vickers hardness commonly cited around 60 to 100 gigapascals (GPa). Other industrially important hard materials include cubic boron nitride (cBN), boron carbide (B4C), silicon carbide (SiC), tungsten carbide (WC), and hard oxides such as alumina. These materials range broadly in chemistry but share high resistance to plastic deformation, though many are brittle.

Hard materials often have high elastic moduli and can retain hardness at elevated temperatures, but many are also brittle and prone to fracture under impact. This brittleness influences tool design, coating strategies, and the choice between bulk material use versus hard coatings.

Manufacture and processing vary: natural diamond occurs in geology, while synthetics are produced by high-pressure high-temperature (HPHT) methods or chemical vapor deposition (CVD). cBN and carbide materials are engineered through specialized synthesis and sintering or sintering of powders. In engineering, hard coatings such as diamond-like carbon, polycrystalline diamond, and various ceramic coatings extend the surface hardness of tools and components.

Applications include cutting and forming tools, grinding wheels, wear-resistant coatings, and protective armor. Hard materials also serve in precision optics, electronics substrates, and medical implants where surface hardness and wear resistance are advantageous. Ongoing research focuses on improving toughness, reducing cost, and developing novel superhard materials.