undefined — Industry Glossary Entry

undefined Diamond-Like Carbon (DLC) is a PVD or PECVD amorphous carbon coating with a coefficient of friction as low as 0.05 against steel. Applied at 150–200 °C (much lower than nitride coatings), 1–3 µm thick. The amorphous carbon structure gives DLC its low friction and chemical inertness, while the sp²/sp³ carbon ratio controls hardness and density.

When to use

• Austenitic stainless slitting (304, 316) — eliminates built-up edge
• Aluminium foil slitting — eliminates welding
• Sticky polymer slitting (LDPE, soft PVC) — low friction releases the film
• Medical and food-contact cutting (chemically inert)

When NOT to use

• Above 350 °C edge temperature (DLC graphitises)
• Abrasive substrates without a hard undercoat (DLC alone is too soft)
• Impact-loaded parts (DLC is too thin)

DLC variants

• a-C:H (hydrogenated DLC): softer, lower stress, 1–2 µm
• ta-C (tetrahedral amorphous carbon): harder, higher stress, 0.5–1.5 µm
• a-C (amorphous carbon): standard

See also: PVD Coating Comparison Table, ta-C coating.