 | Diamond-like Carbon CoatingsDiamond-like carbon (DLC) is applied to surfaces providing a range of benefits, and is used in a diverse array of applications and industries. Renishaw Advanced Materials offers DLC coatings for a wide variety of surfaces, tailored to industry specifications. Our coatings offer superior adhesion and performance. We have extensive experience in the thin-film area, with over 17 years of experience in developing and optimising proprietary processes. What is diamond-like carbon? DLC, one of the many forms or allotropes of carbon, consists of an amorphous arrangement of diamond and graphite, hence diamond-like carbon. DLC is somewhat generic insofar as the process used to deposit the material, combined with modified process parameters, can generate films with many different properties. These can be tailored according to customer requirements and range from polymer-like to near-diamond in terms of hardness. Other physical properties like friction, can vary considerably with coefficients as low as <0.05 Mu.
DLC forms an ionic bond with the substrate and is generally very adherent; however, the substrate material can strongly influence this and interfacial layers can be applied to ensure an appropriate bond. As the essential material in DLC is carbon, it is very corrosion resistant and this property tends to produce a very biocompatible material with good anti-thrombogenic and cytological properties. Deposition process, properties and applications Renishaw Advanced Materials uses Plasma Enhanced Chemical Vapour Deposition (PECVD) techniques to deposit DLC films from approximately 10 nm to 4.0 microns thickness. One of the attributes of this process is that the thermal envelope is at near-room temperature, allowing coatings to be deposited onto thermally sensitive materials such as polymers. Hardened steels are unaffected as the process temperature is below the annealing range. Renishaw Advanced Materials, using extensive expertise, is able to combine other elements with DLC and tailor these composites for a range of innovative applications.
DLC has been successfully applied to many artefacts in diverse industries. We customize the coating technique to ensure optimum properties for specific applications. The properties that can be exploited are: | Co-efficient of friction | 0.2 |
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| Electrical resistivity | 106 x 1212 Ώcm |
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| Hardness | 3000 HV |
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| Abrasion resistance | very good |
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| Corrosion resistance | Acids, alkalis, saline - excellent |
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| Diffusion barriers | for biomedical - limits, Ni/Co/Cr+ migration |
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| Coating thickness | 1.5 μm (may be controlled between 1.3 and 2.0) |
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| Max operating temperature | Continuous 250 °C - intermittent 350 °C |
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| Density | 1.5 – 2.2 x 103 kg/m3 |
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| Thermal conductivity | 1.0 - 0.7 W/m·K |
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| Refractive index | 1.5 – 3.1 |
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| Deposition temperature | ambient to 200 °C |
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