Praxair S.t. Technology, Inc.

Mark W Perpall

Irina Belov

Zhihong Tang

Daryl Copeland

Brian D Fitzwater

Hexavalent chromium-free slurry formulations which are suitable in the production of inorganic overlay coating systems are described. The formulations provide superior hot corrosion and high-temperature oxidation protection for superalloy substrates. A basecoat slurry and topcoat slurry are provided. The basecoat slurry includes an aluminum phosphate based aqueous solution having a molar ratio of Al:P higher than about 1:3 with the incorporation of pigments of either metallic particles, or metal oxide particles, or both in combination. The topcoat slurry includes an aluminum phosphate based aqueous solution having a molar ratio of Al:P higher than about 1:3. An inorganic overlay coating formed on substrate made from the slurry formulation of present invention for hot corrosion protection on superalloy substrate against hot corrosion. Furthermore, a multilayer coating comprises a metallic bond coat and an inorganic overlay coating formed on superalloy substrate to further enhance high-temperature oxidation and hot corrosion protection.

Chromate-free inorganic coating systems for hot corrosion protection of superalloy substrate

Polyurethane-based coatings which exhibit superior erosion and heat resistance combined with antifouling and chemical resistance that are useful for protection of metal components are provided. The coatings are characterized by enhanced particle erosion resistance and enhanced heat resistance and are derived from specific multicomponent slurry compositions.

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Indianapolis, IN, United States of America

Mark W Perpall