Low density composite rocket nozzle components and process for making the same from standard density phenolic matrix, fiber reinforced materials

Abstract

A process for producing low-density composite components as disclosed herein involves forming a compacted and curable pre-preg into a selected level of compaction whereby voids are capable of forming in the compacted curable pre-preg. The compacted curable pre-preg is then cured at a pressure sufficiently low to permit evolving gases to form voids in the pre-preg as the pre-preg cures into the composite article. The pre-preg is only partially debulked in the process. Rocket nozzle components may be produced with reduced densities while still exhibiting satisfactory erosion and other characteristics desired for products subject to the harsh erosive environment of a rocket motor.

What is claimed is:  
     
         1 . A composite article comprising: 
 a pre-preg material comprising a reinforcement impregnated with a thermosetting resin, the composite article having a specific density ranging from approximately 1.00 g/ml to approximately 1.15 g/ml.    
     
     
         2 . The composite article of  claim 1 , wherein the thermosetting resin comprises a carbon phenolic resin.  
     
     
         3 . The composite article of  claim 1 , wherein the thermosetting resin comprises a phenolic resin or an epoxy resin.  
     
     
         4 . The composite article of  claim 1 , wherein the reinforcement comprises glass fibers, boron filaments, boron nitride, silicon carbide, graphite (carbon) filaments, or high modulus organic filaments.  
     
     
         5 . The composite article of  claim 4 , wherein the high modulus organic filaments comprise poly(benzothiazoles) or poly(aromatic amides).  
     
     
         6 . The composite article of  claim 1 , wherein the reinforcement comprises organic filaments of nylon, polyethylene, or aramid.  
     
     
         7 . The composite article of  claim 1 , wherein the pre-preg material further comprises a filler material.  
     
     
         8 . The composite article of  claim 7 , wherein the filler material comprises silica, carbon powder, powdered alumina trihydrate, or antimony oxide.  
     
     
         9 . The composite article of  claim 1 , wherein the composite article comprises a rocket nozzle component.  
     
     
         10 . The composite article of  claim 1 , wherein the composite article comprises a composite panel.  
     
     
         11 . The composite article of  claim 1 , wherein the composite article has an across-ply tensile strength of about 1800 psig to about 3000 psig.  
     
     
         12 . The composite article of  claim 1 , wherein the composite article has an across-ply tensile strength of about 1800 psig to about 2200 psig.