Praxair S.t. Technology, Inc.

Other

Praxair Technology, Inc.

Irina Belov

Daryl Copeland

Vladimir Belov

Zhihong Tang

Mark W Perpall

Brian D Fitzwater

Lothar Puppe

Thomas J Hunt

Thomas F Lewis, Iii

Gerd Passing

Vladimir V Belov

Daryl G Copeland

Thomas F Lewis

Brian 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.

Erosion and corrosion resistant overlay coating systems for protection of metal components

Hexavalent chromium-free slurry formulations which are suitable in the production of ceramic overlay coating systems are described. The formulations provide superior hot corrosion and heat 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:POhigher than about 1:3 with the incorporation of metal oxide particles. The topcoat slurry includes an aluminum phosphate based aqueous solution having a molar ratio of Al:POhigher than about 1:3. Both of the basecoat slurry and the topcoat slurry are hexavalent chromium-free.

Chromate-free ceramic coating compositions for hot corrosion protection of superalloy substrates

Hexavalent chromium-free slurries are provided that are capable of achieving a full cure at temperatures as low as 330-450 degrees F., thus making the coatings especially suitable for application on temperature sensitive base materials. The slurries are suitable in the production of protective coating systems formed by novel silicate-based basecoats that are sealed with novel phosphate-based topcoats. The coating systems exhibit acceptable corrosion and heat resistance and are capable of replacing traditional chromate-containing coating systems.

Chromate-free ceramic compositions with reduced curing temperature

A composition based on a certain chromium-free silicate-based binder is described. The composition is an aqueous solution of lithium-doped potassium silicate in combination with an aluminum or aluminum alloy powder, zinc powder or a combination thereof. The coatings of the present invention are capable of achieving a full cure at temperatures as low as 350-450 degrees F. by the inclusion of a colloidal solution of a nano-sized ceria, thus making the coatings especially suitable for application on temperature sensitive base materials.

Chromium-free silicate-based ceramic compositions with reduced curing temperature

A high surface finish, thermally stable, multilayer slurry-based overlay system suitable for use in a severe thermal environment is disclosed. The disclosed embodiments include a basecoat layer formed from a slurry comprising ceramic pigment filled phosphate-based binder, a second layer formed from a slurry comprising metal oxide pigment or ceramic oxide pigment filled phosphate-based binder, and an optional seal coat layer formed from a phosphate-based binder substantially free of pigments.

Multilayer overlay system for thermal and corrosion protection of superalloy substrates

A novel chromate-free multi-layer coating system composed of a lithium-doped potassium silicate binder based basecoat composition that is sealed with an aluminum phosphate-based top coat composition is described. The multi-layer coating system exhibits superior corrosion and heat oxidation resistance which can replace traditional chromate-containing coating systems.

Chromate-free ceramic coating compositions

A composition based on a certain chromium-free silicate-based binder is described. The one-part slurry composition is an aqueous solution of lithium-doped potassium silicate in combination with an aluminum or aluminum alloy powder. The one-part slurry composition produces a corresponding coating exhibiting improved performance at a reduced coating thickness.

Chromium-free silicate-based ceramic compositions

An improved slurry formulation for the production of a thermal and environmental barrier coatings are provided which can withstand high temperature applications. The slurry includes a combination of a coarse ceramic powder fraction having close porosity particles and a fine ceramic powder fraction. The combination of the two powders produces a bimodal particle size distribution having a controlled amount of closed porosity that imparts desirable properties to the coating produced. The finer solid particles are interdispersed within an aqueous binder to produce a ceramic matrix with sufficient mechanical strength. The closed porosity containing coarse particles are embedded within the resultant ceramic matrix and do not disintegrate under high temperature conditions to impart a temperature resistant, non-collapsing closed porosity to the coating which can also act as an environmental barrier.

Aqueous slurry for the production of thermal and environmental barrier coatings and processes for making and applying the same

Provided is a process for isolating zirconium peroxosulfate and its use, either as is or to prepare high purity zirconium compounds including powders of zirconium dioxide and stabilized zirconia. The process is based on precipitating a peroxide compound from an acidic peroxide solution of zirconium and provides a simple, economical method for producing the zirconium peroxosulfate powder and its derivatives with degree of zirconium recovery more than 99%. This process further provides an effective method for the separation and purification of zirconium from a variety of elements and/or naturally occurring ores.

Process for the isolation and purification of zirconium peroxosulfate and uses thereof

Provided is a novel high selectivity aqueous slurry composition method of utilizing same. The composition includes non-modified silica based abrasive particles in an amount of about 5 to about 50 weight percent, and an organic compound in an amount of about 0.001 to about 2.0 weight percent in an aqueous solution, wherein the silicon oxide to silicon nitride selectivity ratio ranges from about 50 to about 700.

High selectivity colloidal silica slurry

The process produces a stabilized zirconia powder by first contacting zirconium basic carbonate particles with a stabilizer compound. This reacts the zirconium basic carbonate particles with the stabilizer compound through heterogeneous contact to form a stabilized zirconia precursor. The stabilizer compound is for stabilizing a phase structure selected from the group consisting of tetragonal phase, cubic phase and mixtures of tetragonal and cubic phases. And calcining the stabilized zirconia precursor removes gaseous by-products and forms the stabilized zirconia powder. The stabilized zirconia powder has a phase structure selected from the group consisting of tetragonal, cubic and mixtures of tetragonal and cubic.

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Zionsville, IN, United States of America

Irina Belov