News Column

Researchers Submit Patent Application, "Gasket with High Temperature Coating", for Approval

August 28, 2014



By a News Reporter-Staff News Editor at Politics & Government Week -- From Washington, D.C., VerticalNews journalists report that a patent application by the inventors Barrall, Jeffery L. (Lititz, PA); Lehr, Brian C. (Lancaster, PA), filed on February 7, 2014, was made available online on August 14, 2014.

The patent's assignee is Interface Solutions, Inc.

News editors obtained the following quote from the background information supplied by the inventors: "Internal combustion engines for heavy duty vehicular and non-vehicular applications, such as trucks, tractors, buses, well-drilling machines, boring machines, portable pumping units, emergency power generators, and the like, can generate significant amounts of heat and produce exhaust gases that are hotter than the exhaust gases produced by non-commercial cars and trucks. Accordingly, the exhaust piping joints for the exhaust manifolds, the turbocharger, the EGR system, and the catalytic converter of such engines can become exceedingly hot. Unfortunately, exhaust piping gaskets made from the more-common stainless steel alloys, which are generally suitable for the lower exhaust gas temperatures found in non-commercial cars and trucks, will often experience severe oxidation corrosion leading to the deterioration or flaking of their outer surfaces in the heavy duty, high temperature applications. As a result, specialized high temperature gaskets formed from expensive and exotic metal alloys, such as the class of austenitic nickel-chromium-based superalloys produced and sold under the Iconel.TM. brand of materials, may be required.

"Consequently, a need exists for an effective treatment or coating that could be applied to lower cost gasket substrates made from the more-common stainless steels, and that would allow the gaskets to perform effectively and without substantial oxidation corrosion or deterioration or flaking of their outer surfaces in high temperature applications, such as the heavy duty applications described above. It is toward such a high temperature coating or treatment that the present disclosure is directed."

As a supplement to the background information on this patent application, VerticalNews correspondents also obtained the inventors' summary information for this patent application: "Briefly described, one embodiment of the present disclosure comprises a method of making a gasket having a high temperature coating. The method includes obtaining a substrate formed from a metallic material and having the shape of the gasket, and applying a nanoparticle solution or suspension over the outer surfaces of the substrate. The nanoparticle suspension comprises a plurality of nanoparticles suspended in a carrier fluid, and in which the nanoparticles can have an average particle size of less than or about 50 nanometers. The method also includes heating the substrate to a first elevated temperature that is between about 80.degree. C. and 600.degree. C. to form an undercoat layer. The undercoat layer can be a self-protective oxide coating, and is configured to inhibit excess oxidation of the surface of the substrate when the gasket is exposed to temperatures greater than or about 600.degree. C.

"After cooling the substrate and undercoat layer, the method further includes applying a boron nitride coating over at least a portion of the undercoat layer and heating the substrate to a second elevated temperature that is between about 80.degree. C. and 200.degree. C., to dry the boron nitride coating into a overcoat layer on top of the undercoat layer. The overcoat layer is configured to provide lubricity to the undercoat layer and substrate when the gasket is exposed to temperatures greater than about 600.degree. C.

"Another embodiment of the disclosure comprises a gasket having a high temperature coating. The gasket includes a substrate formed from a metallic material and having a shape of a gasket, with the substrate having an upper surface, a lower surface, and an aperture formed therethrough. The gasket also includes an undercoat layer that covers substantially all of the surface area of one or both of the upper surface and the lower surface, with the undercoat layer comprising a self-protective oxide coating formed from a plurality of nanoparticles that have been applied to the surface and heated to a first elevated temperature that is between about 80.degree. C. and 600.degree. C., and is preferably between about 80.degree. C. and 100.degree. C., and for a predetermined period of time. The gasket further includes an overcoat layer on the undercoat layer to provide lubricity to the surface when the gasket is exposed to temperatures greater than about 600.degree. C., with the overcoat layer generally comprising boron nitride.

"Another embodiment of the disclosure comprises a method of making a gasket having a high temperature coating. The method includes obtaining a substrate formed from a metallic material and having a shape of a gasket, the substrate having an upper surface, a lower surface, and an aperture formed therethrough, and applying a nanoparticle suspension over substantially all of the surface area of one or both of the upper surface and the lower surface, with the nanoparticle suspension including a plurality of nanoparticles suspended in a carrier fluid. The method also includes heating the substrate to a first elevated temperature between about 80.degree. C. and about 200.degree. C. to form a self-protective oxide coating, followed by washing the substrate to remove any dried carrier fluid. The substrate can be washed in an ultra-sonic parts washer.

"The method further includes applying a boron nitride coating over at least a portion of the self-protective oxide coating, followed by heating the substrate between about 80.degree. C. and about 200.degree. C. to dry the boron nitride coating and form an overcoat layer. The self-protective oxide coating can be configured to inhibit excess oxidation of the surface of the substrate when the gasket is exposed to temperatures greater than or about 600.degree. C., while the overcoat layer can be configured to provide lubricity to the undercoat layer and substrate when the gasket is exposed to temperatures greater than about 600.degree. C.

"The invention will be better understood upon review of the detailed description set forth below taken in conjunction with the accompanying drawing figures, which are briefly described as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

"The patent or application file contains several photographs executed in color. Copies of this patent or patent application publication with color photographs will be provided by the Office upon request and payment of the necessary fee.

"FIGS. 1A-1C are front views of various representative exhaust gaskets for internal combustion engines as found in the prior art.

"FIG. 2 is a perspective view of an exhaust gasket having a high temperature coating, in accordance with a representative embodiment of the present disclosure.

"FIG. 3 is a cross-sectional side of the exhaust gasket of FIG. 2, as taken along Section Line A-A.

"FIG. 4 is a perspective view of an multi-layer exhaust gasket having a high temperature coating, in accordance with another representative embodiment of the present disclosure.

"FIG. 5 is a flowchart depicting a method for forming the high temperature coating of FIGS. 2-3, in accordance with another representative embodiment of the present disclosure.

"FIGS. 6A-6B are photographs of bare, stainless steel test blanks without coatings, before and after heat aging at 800.degree. C., respectively.

"FIGS. 7A-7B are photographs of stainless steel test blanks with a nanoparticle coating, before and after heat aging at 800.degree. C., respectively.

"FIGS. 8A-8B are photographs of stainless steel test blanks with a boron nitride coating, before and after heat aging at 800.degree. C., respectively.

"FIGS. 9A-9B are photographs of stainless steel test blanks with both a nanoparticle undercoat a boron nitride overcoat after heat aging at 800.degree. C.

"FIG. 10 is a table detailing the anti-friction performance of some of the test blanks shown FIGS. 6A-9B.

"FIGS. 11A-11B are graphs detailing the sealability performance of the test coatings illustrated in FIGS. 8A-8B and 9A-9B, respectively."

For additional information on this patent application, see: Barrall, Jeffery L.; Lehr, Brian C. Gasket with High Temperature Coating. Filed February 7, 2014 and posted August 14, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=5946&p=119&f=G&l=50&d=PG01&S1=20140807.PD.&OS=PD/20140807&RS=PD/20140807

Keywords for this news article include: Chemicals, Chemistry, Nanoparticle, Boron Nitride, Nanotechnology, Stainless Steel, Emerging Technologies, Interface Solutions Inc..

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Source: Politics & Government Week


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