What Does Diamond-Like Carbon Mean?
Diamond-like carbon is amorphous carbon which has some of the valuable properties of diamond. It is a thin carbon-based coating that can be applied on almost any material that is compatible with the vacuum in which it is usually produced. It has unique properties of natural diamond such as:
- Low friction
- High hardness
- Chemical resistance
- High corrosion resistance
Diamond-like carbon exists in seven different forms of amorphous carbon materials. All seven contain significant amounts of sp3 hybridized carbon atoms.
Corrosionpedia Explains Diamond-Like Carbon
Diamond-like carbon is a name attributed to a variety of amorphous carbon materials, some containing up to about 50 at.% hydrogen (a-C:H), others containing less than 1% hydrogen (a-C). Diamond-like carbon films contain significant numbers of sp3 type C bonds, giving them attractive physical and mechanical properties that are similar to diamond.
Diamond-like carbon is typically produced by processes in which high-energy precursive carbons (e.g. in plasmas, in filtered cathodic arc deposition, in sputter deposition and in ion beam deposition) are rapidly cooled or quenched on relatively cold surfaces. When applied in pure form it is as hard as natural diamond, sometimes even harder. In pure form these diamond coatings offer extraordinary protection against abrasive wear and attack from atmospheric moisture and chemical vapors. DLC coatings can have different structures and properties that rely on the ratio of sp3 (diamond) and sp2 (carbon) or other fillers like hydrogen, silicon and metal.
Diamond-like carbon is used in:
- Optical products to create a hard, low-friction, scratch-resistant surface (glass, plastics, mirrors)
- Medical products including implantable joints, catheters, surgical implements, medical instrumentation and packaging
- Thermal applications including thermal print heads and passivation of electronic circuitry
- Barrier applications including pharmaceutical packaging and medical product storage
- Wear applications including plastic molds, gear pumps, extrusion dies, stamping devices, process equipment, magnetic tape heads and computer hard disks