Chemical Vapour Deposition
Chemical Vapour Deposition is a gas phase process where reactant precursor gases form a solid coating on a heated substrate placed in a reaction chamber. Diffusion Alloys carries out the CVD of both titanium nitride (TiN) and titanium carbide (TiC) hard material coatings onto a variety of air-hardenable steels and stellite components. The coatings are deposited in both single and multi-layer forms, with typical coating thicknesses of 5 - 10 μm. We are one of very few CVD TiN and TiC coaters with the technology to chemically remove the coatings without base material damage in the rare event of a coating failure.
Properties and Uses of TiN and TiC CVD Coatings
The properties of our CVD coatings include:
- High resistance to abrasive and adhesive wear
- Fine grained
- High purity
- Harder than similar materials produced using conventional ceramic fabrication process
- distinctive golden-yellow colour.
- hardness of ~ 2200 HV0.025
- metallic grey in appearance
- hardness of ~ 3500 HV0.025
As the rates of both abrasive and adhesive wear are inversely related to hardness, CVD TiC and TiN coatings provide a marked increase in component wear resistance. This, combined with the low coefficient of friction of TiN in contact with steel, leads to substantial improvements in component performance and service life.
Typical areas of application for TiN and TiC CVD coatings include:
- Can seaming tooling for food, beverage & aerosol packing industries
- Metal forming: tooling, dies and punches
- Textile & paper industry components
Diffusion Alloys' CVD Facilities and Processes
Diffusion Alloys operates six atmospheric pressure CVD coating reactors at its facility in Hatfield. As the process temperature is around 1000°C, CVD TiN/TiC coated steel components are hardened and tempered after coating in a dedicated vacuum heat treatment furnace.
As one of only a few CVD suppliers that also has its own in house vacuum heat treatment capability, and supported by its experienced team of material technologists, Diffusion Alloys can offer a one stop resolution for customer coating requirements. Our experienced coating technologists can advise on your specific requests and needs.