Apparatus for pitch densification

Abstract

A pitch densification apparatus may be used to form a carbon-carbon composite material. In some examples, the apparatus is configured to pitch densify a material using one or more of a plurality of different pitch densification techniques. For example, the apparatus may densify a material with a selectable one of the resin transfer molding cycle, the vacuum-assisted resin transfer molding cycle, and/or the vacuum pressure infiltration cycle. The apparatus may respond to initial or changing properties of a material to be densified. In some additional examples, the apparatus includes a mold configured to receive a preform and a portion of solid pitch separate from the preform. The apparatus may include a heating source thermally coupled to the mold that is configured to heat the solid pitch above a melting temperature of the solid pitch. The apparatus may melt the pitch without external pitch melting equipment.

1 . An apparatus comprising:
 a mold configured to receive a material to be densified;   a ram configured to apply a ram pressure to force a pitch into the mold to densify the material;   a gas source configured to apply a gas pressure in the mold to force the pitch into the mold to densify the material; and   a vacuum source operable to create a vacuum pressure in the mold at least prior to application of either the ram pressure or the gas pressure;   wherein the apparatus is configured to densify the material in the mold using a selectable one of the ram, the gas source, the ram and the vacuum source, or the gas source and the vacuum source.   
     
     
         2 . The apparatus of  claim 1 , wherein the material to be densified comprises a carbon fiber material preformed into a shape of a brake disc. 
     
     
         3 . The apparatus of  claim 1 , wherein the ram is configured to apply the ram pressure between approximately 500 pounds per square inch (psi) and approximately 5000 psi. 
     
     
         4 . The apparatus of  claim 1 , wherein the ram comprises at least one of a hydraulic ram, a pneumatic ram, or a screw ram. 
     
     
         5 . The apparatus of  claim 3 , wherein the vacuum source is configured to apply the vacuum pressure between approximately 5 ton and approximately 100 ton. 
     
     
         6 . The apparatus of  claim 1 , wherein the gas source is configured to apply the gas pressure between approximately 10 pounds per square inch (psi) and approximately 1000 psi. 
     
     
         7 . The apparatus of  claim 6 , wherein the gas source comprises nitrogen. 
     
     
         8 . The apparatus of  claim 6 , wherein the vacuum source is configured to apply the vacuum pressure between approximately 10 ton and approximately 20 ton. 
     
     
         9 . The apparatus of  claim 1 , further comprising a density meter configured to determine an initial density of the material, wherein the apparatus is configured to select one of the ram, the gas source, the ram and the vacuum source, or the gas source and the vacuum source to densify the material based on the determined initial density. 
     
     
         10 . The apparatus of  claim 9 , wherein the apparatus is configured to select at least one of the gas source or the gas source and the vacuum source to densify the material to be densified if the initial density is less than or equal to approximately 0.8 grams per cubic centimeter. 
     
     
         11 . The apparatus of  claim 9 , wherein the apparatus is configured to select at least one of the ram or the ram and the vacuum source to densify the material to be densified if the initial density is greater than or equal to approximately 0.8 grams per cubic centimeter. 
     
     
         12 . An apparatus comprising:
 a mold configured to receive a preform;   a ram configured to apply a ram pressure to force a melted pitch into the mold to densify the brake disc preform during at least one of a resin transfer molding cycle or a vacuum-assisted resin transfer molding cycle;   an inert gas source configured to apply a gas pressure in the mold to force the melted pitch into the mold to densify the brake disc preform during a vacuum pressure infiltration cycle; and   a vacuum source configured to create a vacuum pressure in the mold during at least one of the vacuum-assisted resin transfer molding cycle or the vacuum pressure infiltration cycle,   wherein the apparatus is configured to densify the brake disc preform in the mold using a selectable one of the resin transfer molding cycle, the vacuum-assisted resin transfer molding cycle, or the vacuum pressure infiltration cycle.   
     
     
         13 . The apparatus of  claim 12 , wherein the ram comprises at least one of a hydraulic ram, a pneumatic ram, or a screw ram, and the ram pressure is between approximately 500 pounds per square inch (psi) and approximately 5000 psi. 
     
     
         14 . The apparatus of  claim 12 , wherein the inert gas source is configured to apply the between approximately 5 ton and approximately 100 ton. 
     
     
         15 . The apparatus of  claim 12 , further comprising a density meter configured to determine an initial density of the brake disc preform, wherein the apparatus is configured to select one of the resin transfer molding cycle, the vacuum-assisted resin transfer molding cycle, or the vacuum pressure infiltration cycle to densify the preform based on the determined initial density. 
     
     
         16 . The apparatus of  claim 15 , wherein the apparatus is configured to select the vacuum pressure infiltration cycle if the initial density is less than approximately 0.8 grams per cubic centimeter (g/cc), the vacuum-assisted resin transfer molding cycle if the initial density is between approximately 0.8 g/cc and approximately 1.0 g/cc, and the resin transfer molding cycle if the initial density is greater than approximately 1.0 g/cc. 
     
     
         17 . A method comprising:
 inserting a material to be densified into a mold, wherein the mold is part of an apparatus configured to densify the material using a selectable one of a resin transfer molding cycle, a vacuum-assisted resin transfer molding cycle, or a vacuum pressure infiltration cycle;   selecting one of the resin transfer molding cycle, the vacuum-assisted resin transfer molding cycle, or the vacuum pressure infiltration cycle to densify the material in the mold; and   densifying the material in the mold using the selected one of the resin transfer molding cycle, the vacuum-assisted resin transfer molding cycle, or the vacuum pressure infiltration cycle to densify the material to be densified.   
     
     
         18 . The method of  claim 17 , further comprising determining an initial density of the material to be densified, wherein selecting one of a resin transfer molding cycle, a vacuum-assisted resin transfer molding cycle, or a vacuum pressure infiltration cycle to densify the material to be densified comprises selecting the one of the resin transfer molding cycle, the vacuum-assisted resin transfer molding cycle, or the vacuum pressure infiltration cycle based on the determined initial density. 
     
     
         19 . The method of  claim 17 , wherein the material to be densified comprises a brake disc preform, and wherein densifying the material in the mold comprises pitch densifying the material in the mold. 
     
     
         20 . The method of  claim 19 , wherein pitch densifying the material in the mold comprises applying at least one of a ram pressure or an inert gas pressure to the pitch.