Chemically Bonded Phosphate Ceramics Stop Corrosion

Scanning electron microscopy indicates this passivation layer is about 20 microns thick. X-ray diffraction indicates this passivation layer is about 60% iron with components of phosphate, magnesium, silicon, hydrogen, and oxygen.

“History suggests that the new CBPCs passivation layer may resist corrosion indefinitely, as demonstrated by the Iron Pillar of Delhi,” says Wagh. “The Iron Pillar, a 7-meter high, 6-ton Indian artifact that has resisted corrosion for 1600 years with its original inscriptions still legible, has a virtually identical passivation layer to that of the new CBPC.”

In contrast to typical paint polymer coatings that sit on top of the substrate, the new ceramic coating bonds through a chemical reaction with the substrate, so slight surface oxidation actually improves the reaction. This makes it virtually impossible for corrosion promoters like oxygen and humidity to get behind the coating the way they can with ordinary paints.

The corrosion-resistant passivation layer is further protected by a true ceramic outer shell. This dense ceramic outer shell is impermeable to water, and resists impact, abrasion, chemicals, and fire. The ceramic outer shell forms simultaneously with the passivation layer and chemically bonds with it, after acid and base materials mix in the spray gun nozzle then react with the substrate surface. The dual-layer ceramic coating can be used both as a primer and a topcoat, and can be applied in a single pass that’s dry to the touch in a minute, hard dry in 15 minutes, and can be returned to service in an hour.

Though CBPCs such as these have proven themselves in the laboratory and in examples such as the Iron Pillar, Tony Collins knew that the effectiveness of the new material had to be compared to that of traditional anti-corrosion coatings. Duplicating a NASA corrosion test, these new CBPCs have been put to the test against 19 leading anti-corrosion coatings in a live corrosion test, viewable to the public by webcam. Coated samples were scribed, then exposed to 12 hours of sea spray, followed by 12 hours of sunlight (or the UV light equivalent). After 45 days, every other high-performance coating tested failed. Except for the rust on its scribe (gouge) line, the EonCoat sample looked the same as day one.

To monitor another ongoing corrosion test modeled on NASA’s sea spray test, the public can view, zoom, and control a live webcam at www.eoncoat.com. In the latest test, which has passed 120 days and includes brand names matched to numbers, 20 Q panels coated with a popular primer, topcoat, or the new CBPC are sprayed daily with corrosive seawater.

There’s nothing like seeing results with your own eyes. The product has gone more than 10,000 hours with no corrosion in a salt spray ASTM B117 test, but it is believed that engineers, facility managers, and industrial contractors will see value in comparing its effectiveness with leading brands. New CBPCs are a new approach to corrosion protection that should be looked into as aging plants, equipment, and infrastructure need to be safely maintained as long as possible.