Oxynitride glass production procedure

Claim 1

A method of preparing an oxynitrite glass comprising: mixing low-melting temperature glass with discrete particles of a nitrogen-containing compound to form a first batch, heating the first batch, under an atmosphere of flowing nitrogen to a temperature sufficient to melt the glass but below the decomposition temperature of the nitrogen-containing compound, maintaining the temperature for a period of time sufficient for the glass to melt, forming a first melt of molten glass containing particles of nitrogen-containing compound, cooling the melt to form a glass containing particles of nitrogen-containing compound, grinding the glass to form particles of nitrogen-containing compound encapsulated in low-melting temperature glass, mixing the particles with glass-forming oxides in an amount sufficient to bring the composition of the mixture into a glass-forming region, forming a second batch, heating the second batch, under an atmosphere of flowing nitrogen and in the presence of a buffer gas, to a temperature sufficient to melt the low-melting temperature glass and to dissolve the nitrogen-containing compound and glass-forming oxides in the molten glass to form a second melt, maintaining the temperature of the second melt for a period of time sufficient for the nitrogen-containing compound and the glass-forming oxides to dissolve in the molten glass to form a molten mixture and for the molten mixture to homogenize to form a homogeneous melt, and cooling the homogeneous melt, thereby forming an oxynitrite glass.

Claim 2

A method of preparing an oxynitrite glass comprising: mixing low-melting temperature glass with discrete particles of a nitrogen-containing compound to form a first batch, heating the first batch, under an atmosphere of flowing nitrogen to a temperature sufficient to melt the glass but below the decomposition temperature of the nitrogen-containing compound, maintaining the temperature for a period of time sufficient for the glass to melt, forming a first melt of molten glass containing particles of nitrogen-containing compound, cooling the melt to form a glass containing particles of nitrogen-containing compound, grinding the glass to form particles of nitrogen-containing compound encapsulated in low-melting temperature glass, mixing the particles with glass-forming oxides in an amount sufficient to bring the composition of the mixture into a glass-forming region, forming a second batch, heating the second batch, under an atmosphere of flowing nitrogen and in the presence of a buffer gas, to a temperature sufficient to melt the low-melting temperature glass and to dissolve the nitrogen-containing compound and glass-forming oxides in the molten glass to form a second melt, maintaining the temperature of the second melt for a period of time sufficient for the nitrogen-containing compound and the glass-forming oxides to dissolve in the molten glass to form a molten mixture and for the molten mixture to homogenize to form a homogeneous melt, and cooling the homogeneous melt, thereby forming an oxynitrite glass.

Claim 13

A method of preparing a oxynitrate glass containing up to about 15 at. % nitrogen comprising: preparing a low-melting temperature glass from SiO 2 ,Al 2 O 3 , and Y 2 O 3 having a melting temperature below about 1400 degrees C., grinding the low-melting temperature glass to form a powder having a particle size of about 2 to 10 microns, mixing the powder with up to about 50 wt % Si 3 N 4 , as discrete particles to form a first batch, the amount of Si 3 N 4 in the batch being proportional to the amount of nitrogen in the final product, compacting the first batch to form a first compact, heating the compact in a crucible, in an atmosphere of flowing nitrogen and in the presence of Si 3 N 4 to from a buffer gas, to about 1450 degrees C. to melt the low-melting temperature glass to form a melt of low-melting temperature glass containing particles of Si 3 N 4 therein, cooling the melt to form a low-melting temperature glass containing particles of Si 3 N 4 embedded therein, grinding the glass to a particle size of about 20 to 100 microns to form particles of Si 3 N 4 encapsulated in low-melting temperature glass, adding sufficient Y 2 O 3 , SiO 2 , and Al 2 O 3 to the particles to form a mixture having a composition in the glass-forming region, compacting the mixture to 20,000 to 25,000 psi to form a second compact, heating the second compact in a crucible under a flowing nitrogen atmosphere and in the presence of a mixture of a 1:1 ratio of Si 3 N 4 and SiO 2 to from a buffer gas, to a temperature of about 1550 to 1600 degrees C. to melt the low-melting temperature glass and dissolve the Si 3 N 4 , Y 2 O 3 , SiO 2 , and Al 2 O 3 in the molten glass, maintaining this temperature for a period of time sufficient for the glass to melt and for the Si 3 N 4 , Y 2 O 3 , SiO 2 , and Al 2 O 3 to dissolve in the molten glass forming a melt and for the melt to homogenize, and cooling the melt, thereby forming an oxynitrite glass.

Claim 14

A method of preparing a oxynitrate glass containing up to about 15 at. % nitrogen comprising: preparing a low-melting temperature glass from SiO 2 ,Al 2 O 3 , and Y 2 O 3 having a melting temperature below about 1400 degrees C., grinding the low-melting temperature glass to form a powder having a particle size of about 2 to 10 microns, mixing the powder with up to about 50 wt % Si 3 N 4 , as discrete particles to form a first batch, the amount of Si 3 N 4 in the batch being proportional to the amount of nitrogen in the final product, compacting the first batch to form a first compact, heating the compact in a crucible, in an atmosphere of flowing nitrogen and in the presence of Si 3 N 4 to from a buffer gas, to about 1450 degrees C. to melt the low-melting temperature glass to form a melt of low-melting temperature glass containing particles of Si 3 N 4 therein, cooling the melt to form a low-melting temperature glass containing particles of Si 3 N 4 embedded therein, grinding the glass to a particle size of about 20 to 100 microns to form particles of Si 3 N 4 encapsulated in low-melting temperature glass, adding sufficient Y 2 O 3 , SiO 2 , and Al 2 O 3 to the particles to form a mixture having a composition in the glass-forming region, compacting the mixture to 20,000 to 25,000 psi to form a second compact, heating the second compact in a crucible under a flowing nitrogen atmosphere and in the presence of a mixture of a 1:1 ratio of Si 3 N 4 and SiO 2 to from a buffer gas, to a temperature of about 1550 to 1600 degrees C. to melt the low-melting temperature glass and dissolve the Si 3 N 4 , Y 2 O 3 , SiO 2 , and Al 2 O 3 in the molten glass, maintaining this temperature for a period of time sufficient for the glass to melt and for the Si 3 N 4 , Y 2 O 3 , SiO 2 , and Al 2 O 3 to dissolve in the molten glass forming a melt and for the melt to homogenize, and cooling the melt, thereby forming an oxynitrite glass.