Patent ID: 11890609
Assignee: CORNING INCORPORATED
Field: Chemical engineering (Chemistry)
Classification: CPC B | IPC B

Claim 18:
19. A method for treating a honeycomb body, the honeycomb body comprising a skin surrounding a matrix of cells defined by a plurality of intersecting walls, the method comprising:
applying a buffer solution to an exterior surface of the skin, the buffer solution comprising a first pH, wherein a porous inorganic material of the skin comprises a plurality of micro-cracks, and wherein applying the buffer solution to the skin comprises introducing the buffer solution into the plurality of micro-cracks, wherein the buffer solution comprises one or more of: ammonium chloride, ammonium nitrate, ammonium acetate, ammonium hydroxide, potassium phosphate, sodium hydroxide, boric acid, potassium chloride, sodium chloride, potassium carbonate, potassium borate, potassium hydroxide, hydrochloric acid, or potassium acid phthalate; and
coating the exterior surface of the skin with an oxide slurry and depositing inorganic particles of the oxide slurry in pores of the porous inorganic material of the skin to increase a first density of the skin relative to a second density of a porous inorganic material of the matrix, the inorganic particles comprising particles of an oxide or a precursor of the oxide,
wherein the oxide comprises alumina, silica, titania, zirconia, ceria, or aluminum silicate;
wherein the oxide slurry comprises a second pH different from the first pH, wherein the oxide slurry and the buffer solution form a gel that inhibits the inorganic particles of the oxide or the precursor of the oxide from entering the plurality of micro-cracks, and
wherein the method increases the coefficient of thermal expansion of the skin measured at 800° C. by no more than two and a half times.