All You Need To Know About Diamond-Like Carbon Coating

Thanks to its high corrosion resistance, low friction, high durability, and wear-resistant characteristics, DLC coating is becoming an increasingly popular carbon-based application layer across many industries.

Diamond-like carbon coating is a meta-stable hydrogenated carbon (a-C:H). Basically, it’s a class of amorphous carbon (a-C) that displays the unique characteristics of diamond.

The technology was developed around 60 years ago and has evolved greatly since then. It features incredible hardness, chemical inertness, temperature resistance, and optical transparency. The coating technique is extensively used to protect plungers, pistons and pins, jewelry, blades, automotive parts, and more.

Read on to learn about DLC coating in detail.

The DLC Coating Process

DLC coating is slicker and more rigid than natural diamond and Teflon. It can be deposited on nearly all forms of metals, such as steel and iron, and non-metals such as ceramics, glass, silicon, and polymers.

Here’s a step-by-step guide detailing the DLC coating process:

  1. The process starts by heating an object at a low temperature of around 300°F. This preheating phase ensures that any absorbed moisture in the object is outgassed.
  2. After preheating, the object is bombarded with ions of argon gas to clean its surface and remove impurities for a smooth and firm DLC application. This step is known as the ion etching phase.
  3. Now, the object enters the coating phase. Sometimes, an initial under-layer is applied to improve the functionality, quality, and performance of the final product. If no under-layer is required, a dense layer of DLC is deposited on the substrate.
  4. A carbon carrying gas enters the DLC chamber at this point, which is the primary source of the coating. This gas is introduced using auxiliary anodes, after which it undergoes the cracking process.
  5. The cracking process separates carbon from hydrogen gas.
  6. The ionized carbon is directed toward the substrate with an electrical charge that’s applied on the carousel.

Final Steps

The product is rotated inside the chamber while the electric charge directs the ionized carbon on its surface, depositing a firm DLC layer. This process ensures the smooth application of a diamond-like amorphous carbon deposition. It’s equalized by single, double, or 3D axis rotation; this depends on the complexity of the object’s structure.

Types of DLC Coating

There are seven types of DLC coating; each has its unique structure and benefits. DLC consists of two allotropes, diamond and graphite, in which the carbon is structured three-dimensionally. Out of all seven forms, the tetrahedral amorphous carbon is considered the purest, since it contains only sp3 bonded C-atoms.

The efficacy of DLC coating depends on various factors, such as the substrate’s temperature, coating thickness, resistivity, hydrogen content, ion energy and density, and process time.

Characteristics & Benefits of DLC Coating

DLC coating has many commercial and industrial applications. From aircraft engineers to chemists, professionals from every industry understand the importance of DLC coating due to its beneficial properties:

  • Exceptional corrosion resistance
  • Excellent degree of micro-hardness (up to 3,500 HV)
  • Excellent resistance against abrasion and chemical attacks
  • Good dimensional stability and sharp contour accuracy
  • No loss of hardness
  • Glossy, smooth, black/charcoal visual refinement
  • Incredibly low level of roughness (less than Ra 0.02 µm)

Looking for the Best DLC Coating Service Provider?

If you’re looking to leverage the hard and wear resistance coating properties for your products, reach out to NISU Lab, one of the best DLC coating companies in Houston, TX. They offer premium DLC coating services at affordable prices!

Contact their team today for more information.

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