Patent ID: 6308408
Filing Date: 2001-10-30
Classification: F02K,Y10T

Abstract:
A process for fabricating an integral, lightweight combustion chamber/nozzle assembly wherein said assembly comprises (1) a shell of a refractory metal having a configuration defining a chamber of generally frusto-conical contour, the refractory metal shell having an inner and an outer surface and communicating at its base or smaller end with a rocket body, and terminating at its larger end in a generally conical contour which is open at the terminus thereof and which serves as a nozzle for the rocket engine; (2) the entire inner surface of the refractory metal shell having applied thereto a thermal and oxidation barrier layer; and (3) an ablative silica phenolic insert bonded to the exposed surface of the thermal and oxidation barrier layer and configured to provide an inner contour for the combustion chamber, the ablative silica phenolic insert having a taper or gradual reduction in thickness thereof toward the open terminus of the nozzle; which process comprises:(a) providing a graphite mandrel having a shape conforming to the configuration of the metal refractory metal shell;(b) applying a coating of a refractory metal on the entire surface of the graphite mandrel by vacuum plasma spraying of the refractory metal;(c) removing the coating of refractory metal from the graphite mandrel after the coating and mandrel have cooled to provide a refractory metal shell;(d) applying a silicide coating to the entire interior surface of the refractory metal shell;(e) providing a steel mandrel having a shape conforming to a chosen inner surface contour for the combustion chamber;(f) wrapping a silica phenolic tape around the surface of the steel mandrel to provide a silica phenolic tape wrapped billet;(g) curing the silica phenolic tape wrapped billet;(h) machining the exterior surface of the cured silica phenolic tape wrapped billet to conform to the interior surface of the refractory metal shell coated with silicide, thereby producing an ablative insert; and(i) bonding the ablative insert to the silicide coating on the interior surface of the refractory metal shell.