Corning Incorporated

Albert Joseph Fahey

Ljerka Ukrainczyk

Shelby Kerin Wilson

Charlene Marie Smith

Rostislav Vatchev Roussev

Yuhui Jin

Ryan Claude Andrews

Lisa Marie Noni

Qiang Fu

David Eugene Baker

Wei Sun

Methods for regenerating a salt bath composition include heating the salt bath composition to an ion exchange temperature to form a molten salt bath. The methods may further include contacting at least a portion of an ion-exchangeable article that includes lithium oxide (LiO) with the molten salt bath. Lithium cations may diffuse from the ion-exchangeable article and into the molten salt bath. Additionally, the methods may include adding a first phosphate salt to the molten salt bath. A lithium phosphate salt that includes at least a portion of the lithium cations may be formed and precipitate from the molten salt bath. Furthermore, the methods may include adding a multivalent salt that includes a multivalent metal cation to the molten salt bath. A second phosphate salt that includes the multivalent metal cation may be formed and precipitate from the molten salt bath.

Salt bath compositions and methods for regenerating salt bath compositions

Ion-exchanged glass ceramic articles described herein have a stress that decreases with increasing distance according to a substantially linear function from a depth of about 0.07t to a depth of about 0.26t from the outer surface of the ion-exchanged glass ceramic article from a compressive stress to a tensile stress. The stress transitions from the compressive stress to the tensile stress at a depth of from about 0.18t to about 0.25t from the outer surface of the ion-exchanged glass ceramic article. An absolute value of a maximum compressive stress at the outer surface of the ion-exchanged glass article is from 1.8 to 2.2 times an absolute value of a maximum central tension (CT) of the ion-exchanged glass article, and the glass ceramic article has a fracture toughness of 1 MPa&#x221a;m or more as measured according to the double cantilever beam method.

Chemically strengthened lithium disilicate-petalite glass-ceramics

A method of etching a substrate comprises: contacting a substrate having a thickness with an etchant disposed in a vessel for a period of time until the thickness has reduced by at least 2 &#x3bc;m and at an average rate of 1 &#x3bc;m per minute to 6.7 &#x3bc;m per minute, the etchant having a temperature of 170&#xb0; C. to 300&#xb0; C. and comprising a molten mixture of two or more alkali hydroxides; and ceasing contacting the substrate with the etchant. The etchant in some instances comprises a molten mixture of NaOH and KOH. For example, the etchant in some instances includes a molten mixture of 24 wt. % to 72 wt. % NaOH, and 76 wt. % to 28 wt. % KOH. In some instances, the method alters the weight percentage of Na, Kand Liin the composition of the surface of the substrate by less than 1%.

Etching glass and glass ceramic materials in hydroxide containing molten salt

Ion-exchanged glass ceramic articles described herein have a stress that decreases with increasing distance according to a substantially linear function from a depth of about 0.07 t to a depth of about 0.26 t from the outer surface of the ion-exchanged glass ceramic article from a compressive stress to a tensile stress. The stress transitions from the compressive stress to the tensile stress at a depth of from about 0.18 t to about 0.25 t from the outer surface of the ion-exchanged glass ceramic article. An absolute value of a maximum compressive stress at the outer surface of the ion-exchanged glass article is from 1.8 to 2.2 times an absolute value of a maximum central tension (CT) of the ion-exchanged glass article, and the glass ceramic article has a fracture toughness of 1 MPa&#x221a;m or more as measured according to the double cantilever beam method.

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Corning, NY, United States of America

Albert Joseph Fahey