Internal treatment of tubes and hollow objects
The treatment of the inner surface of small-diameter tubes or hollow components requires a specific approach to overcome accessibility constraints and ensure coating uniformity along the entire length of the part. Materia Nova implements two complementary plasma deposition configurations (PVD/PECVD), covering a wide range of internal diameters for metal, glass, and polymer tubes:
- Mini-cathode (patented technology): internal diameters from 4 to 40 mm;
- Conventional cathode: internal diameters above 40 mm.
In both cases, the cathode is inserted axially into the component, and the discharge is generated directly inside the tube in a coaxial cathode/substrate configuration. Plasma confinement in the immediate vicinity of the target, combined with a short target-to-substrate distance, eliminates the line-of-sight constraints inherent to conventional PVD/PECVD processes and enables precise control of coating thickness and uniformity across the entire internal surface. The process is fully dry, vacuum-operated, and requires neither chemical baths nor liquid effluents.
A technology ready for industrial transfer
The mini-cathode technology enables coating of the internal surface of tubes with diameters ranging from 4 to 40 mm and lengths of up to 500 mm. It provides an alternative to wet surface treatment technologies, some of which are increasingly subject to regulatory restrictions, while delivering equivalent functional performance in terms of surface hardness, friction coefficient, and corrosion resistance. This is achieved with coating thicknesses of only a few micrometres, compared with several tens of micrometres for conventional electroplating processes.
The same equipment can deposit various families of materials (metals, oxides, nitrides, carbides) and produce multilayer coating architectures, opening the door to additional functionalities.
Solutions tailored to every application
Thanks to the wide range of Surface treatments available at Materia Nova, internal tube treatment can be adapted to the specific requirements of each industry and application.
