Corrosion resistant metal protection

Greenkote® coating is widely chosen for its exceptional higher performance corrosion resistance, longer wear and other special capabilities. It outperforms many other traditional coating processes such as zinc plating, hot dip, metal flake and sherardizing as well as PVD and CVD. It can also replace chromium-, vanadium- and titanium-based coatings in many applications.

Bottom line, the unique Greenkote thermal diffusion process is selected because it delivers higher performance metal protection — on many fronts…

Unexcelled corrosion resistance

Higher performance Greenkote metal coatings provide exceptionally high corrosion resistance for longer periods of time — both at low and high temperatures, giving high-quality corrosion protection up to 600°C. In corrosion-resistance tests, Greenkote-coated bolts outperform hot-dip galvanized bolts, for example, by a significant margin.

Uniform and conformal coating

Greenkote thermal diffusion process compared with other zinc-based coatings. Click chart to enlarge.

Greenkote provides greater uniformity and conformality of coverage than most other competitive coatings. This includes both ID and OD coverage, blind holes, threads, filets and sharp corners, which are challenging for many coating technologies. And Greenkote offers a wide range of coating thicknesses, from 100 µm down to 5 µm, to further enhance its conformality on very small features.

Metallurgically bonded

By its patented thermal diffusion process Greenkote metal coatings are literally diffused into the surface of the part. Integrally adhered in this way, it provides an extremely strong and permanent metallurgical bond. So, unlike certain other coatings, Greenkote will not delaminate, and it is highly resistant to chipping and similar types of damage. Greenkote can also stand up to crimping, bending and other follow-up processing.

Notably, Greenkote coatings are also weldable in certain applications. The fully-alloyed intermetallic structure of Greenkote gives it superior weldability compared with pure zinc coatings.

Elimination of hydrogen embrittlement

When metals such as steel are exposed to hydrogen the hydrogen atoms can diffuse into the metal, ultimately creating internal pressures, causing the metal to become brittle and to fracture. Some metal coating processes such as electroplating commonly cause hydrogen embrittlement; but fortunately Greenkote does not. Because it involves no sources of hydrogen, Greenkote totally eliminates hydrogen embrittlement as a potential coating problem.

Superior adhesion

The unique micro-roughness of Greenkote’s surface naturally improves the adhesion of top-coat layers when it is used in primer or adhesive bonding applications. It requires no additional surface roughening or adhesion aids. Greenkote is particularly well suited to one- and two-coat adhesive products used for molded rubber compounds of natural and synthetic elastomers.

Longer wear

Compared with zinc plating and hot-dip, Greenkote has greater hardness (up to HV 450–550). Combined with reduced friction, this gives Greenkote greater durability, longer wear and greater resistance to galling and seizing.

Greater cost efficiency

Compared with regular diffusion coatings, the Greenkote batch process uses 90% less coating powder and requires significantly less processing time and energy. It is a streamlined, quick and efficient process — often taking less than 3 hours — which translates to savings across the board. In addition, Greenkote processing equipment is relatively low cost, and does not require significant floor space.

Plus — it’s uniquely eco-friendly!

Greenkote is extremely unusual in that it combines high performance, cost-efficiency — and eco-friendliness! Unlike many competitive processes, Greenkote uses no hazardous materials, generates no toxic wastes and is completely benign to the environment. Which is why it passes even the most strict environmental standards and regulations in industries around the world.

Greenkote^® and the Greenkote logo are registered trademarks of Greenkote PLC.