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Cerablak™ protective coatings on metals & alloys

Much of the near-term product opportunities are targeted toward lower manufacturing or maintenance costs in industrial/chemical processing.  Metals and alloys are extensively used in these industries over a range of temperatures and harsh environments.  Surface modification of these substrates will enable extended lifetimes, better performance, and, in some cases, even improve the quality of the final product.  Corrosion or oxidation of these substrates presents a major problem for industry requiring frequent replacement of parts and increasing production costs due to downtime and other related factors.  Due to the thin, dense, and hermetic nature of Cerablak™, and its ease of applicability, it can be implemented readily with highly effective protection.  In addition, the low surface energy induced by the film will also offer desirable characteristics such as better flow properties for molten polymers or molten metals.  Successful demonstration for coupon-sized as well as full size prototypes have been done for a wide range of substrates to include various grades of steel alloys (including 304, 316, 321), cast iron, aluminum, titanium and its alloys, nickel-based alloys (including Inconel) and superalloys, and copper.

High-temperature oxidation protection

An approximately 200nm thick Cerablak™ film was deposited on SS 304 using a dip-coating process.  Figure on the left shows uncoated and coated SS304 after 1000ºC, 100h anneal in ambient air.  Along with significant cracking and spallation observed for the uncoated coupon, the specific weight gain was almost two orders of magnitude higher than for the Cerablak™-coated coupon.

Protection against salt corrosion

Aluminum alloys coated with an essentially transparent film of Cerablak™ showed a remarkable improvement in protection against salt fog corrosion with virtually no sign of pitting after prolonged exposure (over 500h) in salt fog (ASTM B117).

Plots showing oxidation resistance of Cerablak™ coated nickel-based superalloy. Samples were subject to 100 thermal cycles of 1 hour at 1100°C.

(Thermal cycling tests performed at NASA GRC – POC: Dr. James Smialek)