Airflow masking of carbon-carbon composites for application of antioxidants

Abstract

Mask ( 10, 10′, 21, 22, 30 ) for use in coating a carbon-carbon composite brake disc ( 25 ) with anti-oxidant. The mask is composed of carbon-carbon composite material or nonreactive ceramic material. The mask is configured with edge ridges ( 11, 13, 34, 36 ) that are aligned with the outer and inner annular diameters of the carbon-carbon composite brake disc, a gas flow channel ( 12, 32 ) between the ridges, and a gas access port ( 18, 40 ) that allows gas to enter the gas flow channel. The mask may also include a gas exit port ( 16 ) having a valve ( 17 ) operatively connected thereto, so that gas flow may be restricted when pressure within the mask and carbon-carbon composite brake disc falls below a specified minimum value. Also, a method of avoiding application of liquid antioxidant material to a friction surface of a carbon-carbon composite brake disc, by: covering the friction surface with a mask configured to deliver compressed gas to the friction surface, and directing compressed gas across the friction surface and through pores in the carbon-carbon composite brake disc and/or in the mask while the masked brake disc is in the presence of the antioxidant material in a liquid state.

1 . A mask for coating a carbon-carbon composite brake disc, said mask being composed of carbon-carbon composite material or nonreactive ceramic material, said mask being configured with (i) edge ridges that are aligned with the outer and inner annular diameters of the carbon-carbon composite brake disc, (ii) a gas flow channel between said ridges, and (iii) a gas access port that allows gas to enter said gas flow channel.  
     
     
         2 . The mask of  claim 1 , which further comprises a gas exit port having a valve operatively connected thereto that allows restriction of gas flow when pressure within the mask and carbon-carbon composite brake disc falls below a specified minimum value.  
     
     
         3 . The mask of  claim 1 , wherein said mask is composed of carbon-carbon composite material having an open pore structure or of nonreactive ceramic material having an open pore structure.  
     
     
         4 . The mask of  claim 1  for coating a carbon-carbon composite brake disc having an open pore structure, wherein said mask is composed of carbon-carbon composite material that does not have an open pore structure or of nonreactive ceramic material that does not have an open pore structure.  
     
     
         5 . The mask of  claim 1  wherein at least one of said edge ridges includes a plurality of channels.  
     
     
         6 . The mask of  claim 5  wherein said channels are substantially perpendicular to an edge of said mask.  
     
     
         7 . An assembly comprising: 
 at least one carbon-carbon disk having a first side and a second side and an inner diameter and an outer diameter;    a first annular mask having an inner diameter and an outer diameter, an inner peripheral ridge and an outer peripheral ridge, a gas flow channel between said inner and outer peripheral ridges, and a gas access port communicating with said gas flow channel;    a second annular mask substantially identical to the first annular mask;    said first annular mask being mounted against said first side of said at least one carbon-carbon disk and said second annular mask being mounted against said second side of said at least one carbon-carbon disk.    
     
     
         8 . The assembly of  claim 7  including support means for holding said first annular mask and said second annular mask against said at least one carbon-carbon disk.  
     
     
         9 . The assembly of  claim 7  wherein said first annular mask inner diameter is substantially equal to the inner diameter of said at least one carbon-carbon disk and said first annular mask outer diameter is substantially equal to said at least one carbon-carbon disk outer diameter.  
     
     
         10 . The assembly of  claim 7  wherein said outer peripheral ridge includes an inner edge and an outer edge and a plurality of channels connecting said inner edge and said outer edge.  
     
     
         11 . The assembly of  claim 10  wherein said channels are radially aligned.  
     
     
         12 . The assembly of  claim 10  wherein said channels have a width of from about 0.1 to 1000 micrometers.  
     
     
         13 . The assembly of  claim 12  wherein said channels are radially aligned.  
     
     
         14 . The assembly of  claim 10  wherein said first mask comprises carbon-carbon composite material.  
     
     
         15 . The assembly of  claim 10  wherein said first mask comprises a nonreactive ceramic material.  
     
     
         16 . The assembly of  claim 10  including at least one support fixture holding said first and second masks against said at least one carbon-carbon disk and supporting said first and second masks and said at least one carbon-carbon disk.