Surface hardness of articles by reactive phosphate treatment
AssigneeMcDonnell Douglas Corporation
InventorsRobert A. Dichiara, Jr., Robert W Kreutzer
Life of this patent
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Abstract
An article has at its surface a nonmetallic ceramic form of a cation reactive with phosphate ion to form a ceramic phosphate, such as an oxide of a cation selected from the group consisting of beryllium, aluminum, iron, magnesium, calcium, thorium, barium, zirconium, zinc, silicon, and mixtures thereof. A source of reactive phosphate ions, such as concentrated phosphoric acid or monoaluminum phosphate, is applied to the surface of the article. The surface of the article is thereafter heated to cause the nonmetallic ceramic form of the cation and the source of the reactive phosphate ions to react together, producing a phosphate-bonded hard layer at the surface of the article.
Claims20
A method for preparing a wear-resistant surface, comprising the steps of:
- preparing a slurry comprising an oxide capable of reacting with phosphate ions, a binding agent, and an emissivity-controlling agent;
- applying the slurry to the surface of an article;
- drying the slurry;
- applying a source of reactive phosphate ions to the surface of the article;
- and thereafter
- heating the surface of the article to cause the oxide and the source of the reactive phosphate ions to react together to form a ceramic phosphate.
A method for preparing a wear-resistant surface, comprising the steps of:
- preparing a slurry comprising an oxide powder capable of reacting with phosphate ions, a silica-containing binding agent, and molybdenum disilicide;
- applying the slurry to the surface of a porous article;
- drying the slurry;
- applying an aqueous source of reactive phosphate ions to the surface of the article;
- and thereafter
- heating the surface of the article to cause the oxide and the source of the reactive phosphate ions to react together to form a ceramic phosphate.
A method for preparing an article with a wear-resistant surface, comprising the steps of:
- furnishing an article made of a first ceramic material and having porosity extending through at least a portion of the body adjacent a first surface of the article;
- preparing a slurry of a slurry comprising an oxide powder capable of reacting with phosphate ions, a silica-containing binding agent, and an emissivity-controlling agent;
- impregnating the first surface of the article with the slurry;
- drying the slurry within the porosity of the article;
- firing the slurry to cause the binding agent to bind the ceramic powder and the emissivity-controlling agent to the interior of the porosity of the article;
- applying a source of reactive phosphate ions to the surface of the article;
- and
- heating the surface of the article to cause the oxide and the source of reactive phosphate ions to react together.
Dependencies are inferred from the claim text.