Surface protection of porous ceramic bodies
First Claim
1. A method of protecting the surface of a porous ceramic body, comprising the steps of:
- furnishing a body made of a first ceramic material and having porosity extending through at least a portion of the body adjacent to a first surface of the body;
preparing a slurry of a mixture comprisinga ceramic powder made of a second ceramic material, anda binding agent comprising silica particles;
impregnating the slurry into the first surface of the body so that substantially all of the slurry enters the porosity of the body and substantially none of the slurry resides on the first surface;
drying the slurry in place within the porosity of the body to leave a mixture of ceramic powder and binding agent within the porosity; and
firing the mixture of ceramic powder and binding agent to cause the binding agent to bind the ceramic powder to the interior of the porosity of the body.
2 Assignments
0 Petitions
Accused Products
Abstract
A surface of a porous ceramic body is protected by binding ceramic particles entirely within the subsurface porosity of the body adjacent to the surface but not present as a separately identifiable surface layer. To produce such a protective layer, a slurry of a mixture of a ceramic powder and a silica-containing binding agent is first prepared. The slurry is impregnated into the surface of the body so that all of the slurry enters the porosity of the body and substantially none of the slurry resides on the surface. The slurry is dried in place, and the residual solids are fired to bind the ceramic powder to the interior walls of the porosity. Drying and firing can be accomplished at intermediate temperatures of about 700°-1000° F. using heat lamps, so that the surface protection can be accomplished without removing the ceramic body from a larger structure.
96 Citations
20 Claims
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1. A method of protecting the surface of a porous ceramic body, comprising the steps of:
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furnishing a body made of a first ceramic material and having porosity extending through at least a portion of the body adjacent to a first surface of the body; preparing a slurry of a mixture comprising a ceramic powder made of a second ceramic material, and a binding agent comprising silica particles; impregnating the slurry into the first surface of the body so that substantially all of the slurry enters the porosity of the body and substantially none of the slurry resides on the first surface; drying the slurry in place within the porosity of the body to leave a mixture of ceramic powder and binding agent within the porosity; and firing the mixture of ceramic powder and binding agent to cause the binding agent to bind the ceramic powder to the interior of the porosity of the body. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A method of protecting the surface of a porous ceramic body, comprising the steps of:
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furnishing a body made of a mass of fired fibers of a first ceramic material and having porosity extending through at least a portion of the body adjacent to a first surface of the body; preparing a slurry of a mixture comprising a ceramic powder made of a second ceramic material, and a binding agent comprising silica particles; impregnating the slurry into the first surface of the body so that substantially all of the slurry enters the porosity of the body and substantially none of the slurry resides on the first surface; drying the slurry in place within the porosity of the body to leave a mixture of ceramic powder and binding agent within the porosity; and firing the mixture of ceramic powder and binding agent to cause the binding agent to bind the ceramic powder to the interior of the porosity of the body, so that substantially none of the second ceramic material and silica-containing binding agent lies on the first surface.
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17. A method for the in situ application of surface protecting material to insulative ceramic tiles having porosity extending through at least a portion of the tile adjacent an outer surface thereof, said method comprising the steps of:
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applying a slurry comprising a mixture of a ceramic powder and a binding agent comprising silica particles to the outer surface of an insulative ceramic tile affixed to a surface of an aircraft or spacecraft such that the slurry enters the porosity of the tiles and substantially none of the slurry resides on the outer surface of the tile; drying the slurry in place within the porosity of the tile to leave a mixture of ceramic powder and binding agent within the porosity; and heating the slurry to cause the binding agent to bind the ceramic powder to the interior of the porosity of the tile. - View Dependent Claims (18, 19)
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20. A method of protecting the surface of a porous ceramic body, comprising the steps of:
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furnishing a body made of a first ceramic material and having porosity extending through at least a portion of the body adjacent to a first surface of the body; applying to the first surface of the body a slurry comprising a ceramic powder made of a second ceramic material and a binding agent comprising silica particles so that substantially all of the slurry enters the porosity of the body and substantially none of the slurry resides on the first surface; drying the slurry in place within the porosity of the body to leave a mixture of ceramic powder and binding agent within the porosity; and firing the mixture of ceramic powder and binding agent to cause the binding agent to bind the ceramic powder to the interior of the porosity of the body, so that substantially none of the second ceramic material and silica-containing binding agent lies on the first surface.
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Specification