# US 5,352,638 A · Nickel aluminosilicate glass-ceramics

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- Number: US 5,352,638 A
- Document ID: US5352638A
- Status: Granted
- Kind: A
- Application number: 08/199,753
- Filed: 1994-02-22
- Granted: 1994-10-04
- Earliest claimed: 1994-02-22
- Assignees: Corning Incorporated
- Inventors: George H. Beall; Joseph E. Pierson
- Web page: https://patentgrep.com/patent/US5352638A

## CPC

- C03C 10/0036: {containing SiO2, Al2O3 and a divalent metal oxide as main constituents}
- C03C: CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS

## Abstract

This invention is directed to the production of thermally crystallizable glasses which can be crystallized in situ via heat treatment into glass-ceramic articles containing a nickel spinelloid as the predominant crystal phase. The glasses consist essentially, in weight percent, of 40-60% SiO.sub.2, 10-35% Al.sub.2 O.sub.3, 5-35% NiO, 0-20% MgO, and 0-15% total TiO.sub.2 and/or ZrO.sub.2. The preferred glasses contain at least 2% MgO.

## Claims

### Claim 1

A glass-ceramic article containing a nickel spinelloid as the predominant crystal phase, said glass-ceramic article consisting essentially, expressed in terms of weight percent on the oxide basis, of 40-60% SiO.sub.2, 10-35% Al.sub.2 O.sub.3, 5-35% NiO, 0-20% MgO, and 0-15% total TiO.sub.2 and/or ZrO.sub.2.

### Claim 2 (depends on 1)

A glass-ceramic article according to claim 1 containing at least 2% MgO.

### Claim 3 (depends on 2)

A glass-ceramic article according to claim 2 containing 5-15% MgO.

### Claim 4

A method for making a glass-ceramic article containing a nickel spinelloid as the predominant crystal phase comprising the steps of:
(a) melting a batch for a glass consisting essentially, expressed in terms of weight percent on the oxide basis, of 40-60% SiO.sub.2, 10-35% Al.sub.2 O.sub.3, 5-35% NiO, 0-20% MgO, and 0-15% total TiO.sub.2 and/or ZrO.sub.2 ;
(b) cooling said melt to a temperature at least below the transformation range of said glass and simultaneously forming a glass body therefrom of a desired configuration;
(c) exposing said glass body to a temperature between about 800.degree.-850.degree. C. for a time sufficient to generate the development of nuclei therein;
(d) exposing said nucleated glass body to a temperature between about 850.degree.-1200.degree. C. for a time sufficient to cause the growth of nickel spinelloid crystals in situ on said nuclei to form a glass-ceramic body; and thereafter
(e) cooling said glass-ceramic body to room temperature.

### Claim 5 (depends on 4)

A method according to claim 4 wherein said glass contains at least 2% MgO.

### Claim 6 (depends on 5)

A method according to claim 5 wherein said glass contains 5-15% MgO.