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US3956531A Expired / Lapsed US ⏱️ 0.0 years remaining

Chromium oxide densification, bonding, hardening and strengthening of bodies having interconnected porosity

Assignee: Kaman Sciences Corp
•
Filing: 1972-09-18
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Granted: 1976-05-11
•
Expires: 1992-09-18
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Abstract

Abstract Chromium oxide densification, bonding, hardening and strengthening of bodies having interconnecting porosity therein by impregnation with a chromium compound convertible to chromium oxide on heating, heating the impregnated body to convert the compound to chromium oxide and repeating the impregnation and heating steps. The body may be of any material composed of an oxide, has an oxide constituent or will form a well adhering oxide on its surface.

Inventors

  • 👤 Peter K. Church
  • 👤 Oliver J. Knutson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 22:23
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C04B33/00; C04B33/32; C04B41/45; C04B41/50; C04B41/5025; C04B41/5033; C04B41/80; C04B41/81; C04B41/85; C04B41/87; C04B41/89; F; F02; F02B; F02B75/00; F02B75/02; F02B2075/022; F02B2075/027

Claims Analysis

Total Claims: 65
Claim 1
Independent Claim 147 words
The method of densifying, hardening and strengthening of bodies and coatings having interconnected porosity which comprises the steps of: impregnating a porous body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body, wherein the body consists of a material which is comprised of an oxide; is insoluble in and non-adversely reactive with the solution of a chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant to chromium oxide wherein the chromium compound is a mixture of chromic acid and a chromate.
Claim 2
Independent Claim 147 words
The method of densifying, hardening and strengthening of bodies and coatings having interconnected porosity which comprises the steps of: impregnating a porous body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body, wherein the body consists of a material which is comprised of an oxide; is insoluble in and non-adversely reactive with the solution of a chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant to chromium oxide wherein the chromium compound is a mixture of chromic acid and a chromate.
Claim 3
Independent Claim 155 words
The method of densifying, hardening and strengthening of bodies and coatings having interconnected porosity which comprises the steps of: impregnating a porous body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body, wherein the body consists of a material which is comprised of an oxide; is insoluble in and non-adversely reactive with the solution of a chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant to chromium oxide wherein the chromium compound is chromic acid comprising chromium trioxide dissolved in water to provide a specific gravity of about 1.65.
Claim 4
Independent Claim 155 words
The method of densifying, hardening and strengthening of bodies and coatings having interconnected porosity which comprises the steps of: impregnating a porous body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body, wherein the body consists of a material which is comprised of an oxide; is insoluble in and non-adversely reactive with the solution of a chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant to chromium oxide wherein the chromium compound is chromic acid comprising chromium trioxide dissolved in water to provide a specific gravity of about 1.65.
Claim 5
Independent Claim 160 words
The method of densifying, hardening and strengthening of bodies and coatings having interconnected porosity which comprises the steps of: impregnating a porous body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body, wherein the body consists of a material which is comprised of an oxide; is insoluble in and non-adversely reactive with the solution of a chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant to chromium oxide wherein the chromium compound is chromic acid comprising chromium trioxide dissolved in water with excess chromium trioxide added to provide a specific gravity of about 1.7.
Claim 6
Independent Claim 160 words
The method of densifying, hardening and strengthening of bodies and coatings having interconnected porosity which comprises the steps of: impregnating a porous body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body, wherein the body consists of a material which is comprised of an oxide; is insoluble in and non-adversely reactive with the solution of a chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant to chromium oxide wherein the chromium compound is chromic acid comprising chromium trioxide dissolved in water with excess chromium trioxide added to provide a specific gravity of about 1.7.
Claim 7
Independent Claim 145 words
The method of forming, densifying, hardening and strengthening of bodies having interconnected porosity which comprises the steps of: forming a porous body of a material which is comprised of an oxide; is insoluble in or non-adversely reactive with the solution of chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant to chromium oxide; impregnating the formed body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body wherein the chromium compound is a mixture of chromic acid and a chromate.
Claim 8
Independent Claim 145 words
The method of forming, densifying, hardening and strengthening of bodies having interconnected porosity which comprises the steps of: forming a porous body of a material which is comprised of an oxide; is insoluble in or non-adversely reactive with the solution of chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant to chromium oxide; impregnating the formed body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body wherein the chromium compound is a mixture of chromic acid and a chromate.
Claim 9
Independent Claim 156 words
The method of forming, densifying, hardening and strengthening of bodies having interconnected porosity which comprises the steps of: forming a porous body of a material which is comprised of an oxide; is insoluble in or non-adversely reactive with the solution of chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant to chromium oxide; impregnating the formed body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body wherein the chromium compound is chromic acid reduced by a reducing agent selected from the group consisting of tartaric acid, carbon, and formic acid.
Claim 10
Independent Claim 156 words
The method of forming, densifying, hardening and strengthening of bodies having interconnected porosity which comprises the steps of: forming a porous body of a material which is comprised of an oxide; is insoluble in or non-adversely reactive with the solution of chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant to chromium oxide; impregnating the formed body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body wherein the chromium compound is chromic acid reduced by a reducing agent selected from the group consisting of tartaric acid, carbon, and formic acid.
Claim 11
Independent Claim 166 words
The method of forming, densifying, hardening and strengthening of bodies having interconnected porosity which comprises the steps of: forming a porous body of a material which is comprised of an oxide; is insoluble in or non-adversely reactive with the solution of chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in convertng the chromium compound impregnant to chromium oxide; impregnating the formed body with a solution of a soluble chromium compound capable of being converted to a chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body wherein the chromium compound is chromic acid having dissolved therein a compound selected from the group consisting of Cr 2 O 3 . zH 2 O, Cr 2 O 3 and chromium hydroxide.
Claim 12
Independent Claim 166 words
The method of forming, densifying, hardening and strengthening of bodies having interconnected porosity which comprises the steps of: forming a porous body of a material which is comprised of an oxide; is insoluble in or non-adversely reactive with the solution of chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in convertng the chromium compound impregnant to chromium oxide; impregnating the formed body with a solution of a soluble chromium compound capable of being converted to a chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body wherein the chromium compound is chromic acid having dissolved therein a compound selected from the group consisting of Cr 2 O 3 . zH 2 O, Cr 2 O 3 and chromium hydroxide.
Claim 13
Independent Claim 156 words
The method of forming, densifying, hardening and strengthening of bodies having interconnected porosity which comprises the steps of: forming a porous body of a material which is comprised of an oxide; is insoluble in or non-adversely reactive with the solution of chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant to chromium oxide; impregnating the formed body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body wherein the chromium compound is a reaction product of chromic acid and an oxide selected from the group consisting of magnesium and zinc oxides.
Claim 14
Independent Claim 156 words
The method of forming, densifying, hardening and strengthening of bodies having interconnected porosity which comprises the steps of: forming a porous body of a material which is comprised of an oxide; is insoluble in or non-adversely reactive with the solution of chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant to chromium oxide; impregnating the formed body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body wherein the chromium compound is a reaction product of chromic acid and an oxide selected from the group consisting of magnesium and zinc oxides.
Claim 15
Independent Claim 170 words
The method of forming, densifying, hardening and strengthening of bodies having interconnected porosity which comprises the steps of: forming a porous body of a material which is comprised of an oxide; is insoluble in or non-adversely reactive with the solution of chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant to chromium oxide; impregnating the formed body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body wherein the material from which the body is formed is particulate and has an amount of the chromium compound mixed therewith prior to forming sufficient to provide chromium compound at each point of contract between the particulate material.
Claim 16
Independent Claim 170 words
The method of forming, densifying, hardening and strengthening of bodies having interconnected porosity which comprises the steps of: forming a porous body of a material which is comprised of an oxide; is insoluble in or non-adversely reactive with the solution of chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant to chromium oxide; impregnating the formed body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body wherein the material from which the body is formed is particulate and has an amount of the chromium compound mixed therewith prior to forming sufficient to provide chromium compound at each point of contract between the particulate material.
Claim 17
Independent Claim 156 words
The method of densifying, hardening and strengthening of bodies and coatings having interconnected porosity which comprises the steps of: impregnating a porous body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body, wherein the body consists of a material which is comprised of an oxide; is insoluble in and non-adversely reactive with the solution of a chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant to chromium oxide wherein the chromium compound is a mixture of chromic acid and a chromate selected from the group consisting of magnesium and zinc.
Claim 18
Independent Claim 156 words
The method of densifying, hardening and strengthening of bodies and coatings having interconnected porosity which comprises the steps of: impregnating a porous body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body, wherein the body consists of a material which is comprised of an oxide; is insoluble in and non-adversely reactive with the solution of a chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant to chromium oxide wherein the chromium compound is a mixture of chromic acid and a chromate selected from the group consisting of magnesium and zinc.
Claim 19
Independent Claim 148 words
The method of forming, densifying, hardening and strengthening of bodies having interconnected porosity which comprises the steps of: forming a porous body of a material which is comprised of an oxide; is insoluble in or non-adversely reactive with the solution of chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant to chromium oxide; impregnating the formed body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body wherein the chromium compound is a chromate selected from the group consisting of magnesium and zinc.
Claim 20
Independent Claim 148 words
The method of forming, densifying, hardening and strengthening of bodies having interconnected porosity which comprises the steps of: forming a porous body of a material which is comprised of an oxide; is insoluble in or non-adversely reactive with the solution of chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant to chromium oxide; impregnating the formed body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body wherein the chromium compound is a chromate selected from the group consisting of magnesium and zinc.
Claim 21
Independent Claim 152 words
The method of forming, densifying, hardening and strengthening of bodies having interconnected porosity which comprises the steps of: forming a porous body of a material which is comprised of an oxide; is insoluble in or non-adversely reactive with the solution of chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant to chromium oxide; impregnating the formed body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body wherein the chromium compound is of the general formula xCrO 3 . yCr 2 O 3 . zH 2 O.
Claim 22
Independent Claim 152 words
The method of forming, densifying, hardening and strengthening of bodies having interconnected porosity which comprises the steps of: forming a porous body of a material which is comprised of an oxide; is insoluble in or non-adversely reactive with the solution of chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant to chromium oxide; impregnating the formed body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body wherein the chromium compound is of the general formula xCrO 3 . yCr 2 O 3 . zH 2 O.
Claim 23
Independent Claim 154 words
The method of densifying, hardening and strengthening of bodies and coatings having interconnected porosity which comprises the steps of: impregnating a porous body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body, wherein the body consists of a material which is comprised of an oxide; is insoluble in and non-adversely reactive with the solution of a chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant to chromium oxide wherein the chromium compound is of the general formula xCrO 3 . yCr 2 O 3 . zH 2 O.
Claim 24
Independent Claim 154 words
The method of densifying, hardening and strengthening of bodies and coatings having interconnected porosity which comprises the steps of: impregnating a porous body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body, wherein the body consists of a material which is comprised of an oxide; is insoluble in and non-adversely reactive with the solution of a chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant to chromium oxide wherein the chromium compound is of the general formula xCrO 3 . yCr 2 O 3 . zH 2 O.
Claim 25
Dependent Claim 39 words
The method of claim 12 wherein the chromium compound is chromic acid having dissolved therein a compound selected from the group consisting of Cr 2 O 3 ; Cr 2 O 3 . xH 2 O; and, chromium hydroxide.
Claim 26
Dependent Claim 38 words
The method of claim 13 wherein the chromium compound is chromic acid having chromium oxide dissolved therein to provide a specific gravity of about 1.84 which is then diluted about 3 parts chromium solution to 1 part water.
Claim 27
Dependent Claim 29 words
The method of claim 12 wherein the chromium compound is chromic acid reduced by a reducing agent selected from the group consisting of tartaric acid, carbon, and formic acid.
Claim 28
Dependent Claim 28 words
The method of claim 15 wherein the chromium compound is chromic acid having an amount of carbon dissolved therein sufficient to provide a specific gravity of about 1.7.
Claim 29
Dependent Claim 34 words
The method of claim 16 wherein the carbon is dissolved in the chromic acid with a ratio of about 9 parts by weight of carbon to about 340 parts by weight of chromium trioxide.
Claim 30
Dependent Claim 34 words
The method of claim 16 wherein the carbon is dissolved in the chromic acid with a ratio of about 210 parts by weight of carbon to about 1812 parts by weight of chromium trioxide.
Claim 31
Independent Claim 156 words
The method of forming, densifying, hardening and strengthening of bodies having interconnected porosity which comprises the steps of: forming a porous body of a material which is comprised of materials selected from the group consisting of nitrides, carbides, silicides, silicates, titanates, stannates, zirconates, borides, intermetallics, ferrites, metals, metal alloys, oxides, complex oxides and mixtures thereof; is insoluble in or non-adversely reactive with the solution of chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant to chromium oxide; impregnating the formed body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body.
Claim 32
Independent Claim 156 words
The method of forming, densifying, hardening and strengthening of bodies having interconnected porosity which comprises the steps of: forming a porous body of a material which is comprised of materials selected from the group consisting of nitrides, carbides, silicides, silicates, titanates, stannates, zirconates, borides, intermetallics, ferrites, metals, metal alloys, oxides, complex oxides and mixtures thereof; is insoluble in or non-adversely reactive with the solution of chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant to chromium oxide; impregnating the formed body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body.
Claim 33
Dependent Claim 35 words
The method of claim 19 wherein the bodies are comprised of materials selected from the group consisting of silicon carbide, silicon nitride, boron carbide, molybdenum silicide, zirconium silicate, calcium titanite, magnesium stannate and cesium zirconate.
Claim 34
Dependent Claim 13 words
The methods of claim 19 wherein the chromium compound is a chromic acid.
Claim 35
Dependent Claim 15 words
The method of claim 19 wherein the soluble chromium compound is an acidic chromium compound.
Claim 36
Dependent Claim 35 words
The method of claim 19 wherein the material from which the body is formed is a slurry of finely divided particles in a liquid which is applied to a substrate to form a coating thereon.
Claim 37
Dependent Claim 51 words
The method of claim 23 wherein the slurry is comprised of a mixture of particles of a relatively low expansion rate material and particles of a relatively high expansion rate material in such proportions as to provide a combined expansion rate substantially matching the substrate to which the slurry is applied.
Claim 38
Dependent Claim 30 words
The method of claim 23 wherein the slurry includes an amount of a ductile metal powder sufficient to tolerate substantial thermal expansion mismatches between the substrate and the cured coating.
Claim 39
Dependent Claim 56 words
The method of claim 19 wherein the porous body is a porous coating formed on a substrate wherein the porous bodies are comprised of an in situ oxide coating on stainless steel; stellite; 2/3 nickel 1/3 copper alloy; 78% nickel, 15% chromium, 6% iron alloy; navel bronze and bronze alloys; and boron carbidesilicon carbide alloyed material.
Claim 40
Dependent Claim 11 words
The method of claim 26 wherein the coating is iron oxalate.
Claim 41
Dependent Claim 11 words
The method of claim 26 wherein the coating is iron oxide.
Claim 42
Independent Claim 145 words
The method of forming, densifying, hardening and strengthening of bodies having interconnected porosity which comprises the steps of: forming a porous body of a material which is comprised of an oxide; is insoluble in or non-adversely reactive with the solution of chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant to chromium oxide; impregnating the formed body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body where the porous body is a porous coating electrolytically formed on a substrate.
Claim 43
Independent Claim 145 words
The method of forming, densifying, hardening and strengthening of bodies having interconnected porosity which comprises the steps of: forming a porous body of a material which is comprised of an oxide; is insoluble in or non-adversely reactive with the solution of chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant to chromium oxide; impregnating the formed body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body where the porous body is a porous coating electrolytically formed on a substrate.
Claim 44
Dependent Claim 11 words
The method of claim 29 wherein the coating is anodized aluminum.
Claim 45
Dependent Claim 11 words
The method of claim 29 wherein the coating is titanium oxide.
Claim 46
Dependent Claim 11 words
The method of claim 29 wherein the coating is chrome plating.
Claim 47
Dependent Claim 12 words
The method of claim 32 wherein the chromium compound is chromic acid.
Claim 48
Independent Claim 159 words
The method of densifying, hardening and strengthening of bodies and coatings having interconnected porosity which comprises the steps of: impregnating a porous body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body, wherein the body consists of a material which is comprised of materials selected from the group consisting of nitrides, carbides, silicides, borides, intermetallics, stannates, zirconates, titanates, borocarbides, silicates, ferrites, metals, metal alloys, oxides, complex oxides and mixtures thereof; is insoluble in and non-adversely reactive with the solution of a chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant, to chromium oxide.
Claim 49
Independent Claim 159 words
The method of densifying, hardening and strengthening of bodies and coatings having interconnected porosity which comprises the steps of: impregnating a porous body with a solution of a soluble chromium compound capable of being converted to chromium oxide on being heated; drying and curing said impregnated body by heating same to a temperature sufficient to convert the chromium compound in situ to chromium oxide; and, repeating the impregnation and curing steps at least once to densify, harden and strengthen the body, wherein the body consists of a material which is comprised of materials selected from the group consisting of nitrides, carbides, silicides, borides, intermetallics, stannates, zirconates, titanates, borocarbides, silicates, ferrites, metals, metal alloys, oxides, complex oxides and mixtures thereof; is insoluble in and non-adversely reactive with the solution of a chromium compound selected as an impregnant; and is inherently temperature stable to at least the minimum heat cure temperature employed in converting the chromium compound impregnant, to chromium oxide.
Claim 50
Dependent Claim 65 words
The method of claim 34 wherein the bodies are comprised of materials selected from the group consisting of silicon carbide, silicon nitride, cesium stannate, cesium titanate, cesium zirconate, magnesium titanate, magnesium stannate, strontium zirconate, chromium carbide, boron silicide, chromium silicide, titanium boride, vanadium boride, aluminum borocarbide, vanadium carbide, titanium nitride, iron nitride, boron carbide, molybdenum silicide, zirconium silicate, calcium titanite, magnesium stannate and cesium zirconate.
Claim 51
Dependent Claim 13 words
The methods of claim 34 wherein the chromium compound is a chromic acid.
Claim 52
Dependent Claim 15 words
The method of claim 34 wherein the soluble chromium compound is an acidic chromium compound.
Claim 53
Dependent Claim 29 words
The method of claim 37 wherein the chromium compound is a reaction product of chromic acid and an oxide selected from the group consisting of magnesium and zinc oxides.
Claim 54
Dependent Claim 25 words
The method of claim 38 wherein the chromium compound is chromic acid having magnesium oxide dissolved therein to provide a specific gravity of about 1.3.
Claim 55
Dependent Claim 33 words
The method of claim 39 wherein the magnesium oxide is dissolved in the chromic acid with a ratio of about 40.3 parts by weight to about 100 parts by weight of chromium trioxide.
Claim 56
Dependent Claim 25 words
The method of claim 38 wherein the chromium compound is chromic acid having magnesium oxide dissolved therein to provide a specific gravity of about 1.65.
Claim 57
Dependent Claim 41 words
The method of claim 41 wherein the magnesium oxide is dissolved in the chromic acid with a ratio of about 40.3 parts by weight to about 200 parts by weight of chromium trioxide to provide a specific gravity of about 1.65.
Claim 58
Dependent Claim 41 words
The method of claim 41 wherein the magnesium oxide is dissolved in the chromic acid with a ratio of about 40.3 parts by weight to about 400 parts by weight of chromium trioxide to provide a specific gravity of about 1.65.
Claim 59
Dependent Claim 41 words
The method of claim 41 wherein the magnesium oxide is dissolved in the chromic acid with a ratio of about 40.3 parts by weight to about 600 parts by weight of chromium trioxide to provide a specific gravity of about 1.65.
Claim 60
Dependent Claim 41 words
The method of claim 41 wherein the magnesium oxide is dissolved in the chromic acid with a ratio of about 40.3 parts by weight to about 1000 parts by weight of chromium trioxide to provide a specific gravity of about 1.65.
Claim 61
Dependent Claim 25 words
The method of claim 38 wherein the chromium compound is chromic acid having zinc oxide dissolved therein to provide a specific gravity of about 1.65.
Claim 62
Dependent Claim 41 words
The method of claim 46 wherein the zinc oxide is dissolved in the chromic acid with a ratio of about 40.7 parts by weight to about 200 parts by weight of chromium trioxide to provide a specific gravity of about 1.65.
Claim 63
Dependent Claim 41 words
The method of claim 46 wherein the zinc oxide is dissolved in the chromic acid with a ratio of about 40.7 parts by weight to about 400 parts by weight of chromium trioxide to provide a specific gravity of about 1.65.
Claim 64
Dependent Claim 41 words
The method of claim 46 wherein the zinc oxide is dissolved in the chromic acid with a ratio of about 40.7 parts by weight to about 800 parts by weight of chromium trioxide to provide a specific gravity of about 1.65.
Claim 65
Dependent Claim 41 words
The method of claim 46 wherein the zinc oxide is dissolved in the chromic acid with a ratio of about 40.7 parts by weight to about 1000 parts by weight of chromium trioxide to provide a specific gravity of about 1.65.

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1979-05-11 1979-11-10 1980-05-11 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1983-05-11 1983-11-10 1984-05-11 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1987-05-11 1987-11-10 1988-05-11 $7700.00 Window Closed / Lapsed

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