Summary of Frequently Asked Questions about DLC Coatings

▼ 01 How thick is the DLC coating? Why do some companies say that DLC hardness can go up to 4000HV while yours is 2000HV? #

Tool-plated DLC is typically 1-3 microns thick, which includes some of the thickness of the priming layer. The surface hardness of DLC varies slightly from company to company, usually between 1800HV and 2200HV. Decorative plated DLC is within 1 micron; however, closer to 0.5 micron, the DLC will appear as a dazzle, or heptachromatic DLC. uniform, varying colors that reflect the film thickness of the DLC.

DLC stands for Diamond Like Carbon. Because most of the carbon films deposited by PeCVD with methane gas have a hardness between 1800HV and 2200HV, are dominated by SP2 bonds and contain hydrogen, it is customary to refer to this type of carbon film as DLC.

DLC can also be broadly understood as a hybridized film system consisting of SP2 and SP3 bonds. Among them, graphite is used as the target material, hydrogen-free amorphous tetrahedral carbon film ta-C, unlike the narrow DLC which is dominated by SP2 bonds, ta-C is dominated by SP3 bonds (diamond structure). With the increase of SP3 content, the hardness increases significantly even up to 7000 HV, but the film thickness is usually within 0.5 micron due to internal stress.

Broadly speaking, there is a relationship between the hardness and thickness of DLC. However, DLC is a highly customizable film system, and different properties of carbon films can be achieved by changing the film lattice structure, elemental references, and coating process, such as ultra-thick DLC above 8 microns and ultra-thick ta-C (hardness is usually reduced to below 3500 HV). Some of them can realize super lubricating DLC below 0.05, or super hydrophobic DLC with F. Or high temperature resistant DLC with silicon, etc. with a temperature resistance of 450°.

Anyway, the DLC is an imaginative coating. Each factory process is not quite the same, so don't get too hung up on the name of the coating. Each factory also has a DLC type that is always in the furnace, and this is usually their most consistent DLC coating.