Method of Oper tion: Nozzles used in CVD furnaces deliver cold, unre- acted gas to the surface being treated. The gas must be both unreacted so that the coating occurs on the intended surface rather than on the inside of the nozzle, and close to the surface to be treated so that the surface and not the walls of the furnace get sprayed. A nozzle is like a paint spray gun, which must be close to the part being painted.
Typic l Missile-Rel ted Uses: These nozzles are required parts of pyro- lytic deposition equipment used to make critical, high-heat-tolerant parts such as rocket nozzles and reentry vehicle nose tips.
Other Uses: These nozzles are used to make high-heat-tolerant parts for jet engines.
Appe r nce ( s m nuf ctured): Nozzles for CVD furnaces are designed to tolerate high furnace temperatures either by construction from very high-temperature-resistant material such as graphite or by water-cooling. Nozzle dimensions are approximately half the width of the furnace. Small nozzles are typically made of graphite because it is inexpensive, easily re- placed, and lightweight (approximately 0.5 to 2.5 kg). Larger nozzles for production furnaces are often made of metal, require water cooling, may have integral attachment flanges, and weigh upwards of 25 kg.
Nozzles are made in varying lengths, which depend on the size of the fur- nace and the surface. The larger, more complex, water-cooled nozzles are up to 1.5 m long, with their tubular portion 20 cm in diameter. However, because some portion of most nozzles is custom designed, there is no stan- dard shape or size.
Appe r nce ( s p ck ged): Packaging for the nozzle and pyrolytic deposi- tion equipment is suitable for preventing damage to a highly durable pipe with somewhat fragile valves and fittings. Typically, several nozzles are shipped together in well protected packaging separate from any large furnace shell.
(c) Equipment and process controls, and specially designed software therefor, designed or modified for densification and pyrolysis of structural composite rocket nozzles and reentry vehicle nose tips.
nd Purpose: Specialized equipment and process controls are
essential for the densification and pyrolysis necessary to composites used for rocket nozzles and reentry vehicle
produce structural nose tips. Specially
designed software trol the processes
often is required to operate to produce these structural
the equipment and/or con- composites. Manufacturing
items from this type of process conditions such
material usually requires cycling through various as high temperature and/or pressure. Precise con-