Patent ID: 11891331
Assignee: CORNING INCORPORATED
Field: Other special machines (Mechanical engineering)
Classification: CPC C | IPC C

Claim 0:
1. A method of nitridizing a glass article, comprising:
heating a glass article to a first temperature in a heating chamber;
supplying a nitridizing gas comprising NH3 to the heating chamber, wherein the nitridizing gas has an initial concentration of NH3 ([NH3]0);
heating the nitridizing gas to the first temperature at a first time;
exposing the glass article to the nitridizing gas within a contact time (tc) of the first time according to formula (IV):, t
          c
        
        =
        
          
            -
            
              [
              
                ln
                ⁡
                
                  (
                  
                    
                      
                        [
                        
                          NH
                          3
                        
                        ]
                      
                      
                        t
                        c
                      
                    
                    
                      
                        [
                        
                          NH
                          3
                        
                        ]
                      
                      0
                    
                  
                  )
                
              
              ]
            
          
          /
          
            [
            
              
                (
                
                  5.12
                  ×
                  
                    10
                    6
                  
                
                )
              
              ⁢
              
                e
                
                  (
                  
                    
                      -
                      17681
                    
                    /
                    T
                  
                  )
                
              
            
            ]
          
        
      
    
    
      
        (
        IV
        )
      
    
  

where [NH3]tc is a concentration of NH3 in the nitridizing gas at time tc, [NH3]0 is a concentration of NH3 at the first time, tc is in seconds, and T is the first temperature (in Kelvin), and
wherein a ratio of [NH3]tc:[NH3]0 is at least about 0.0001.