Test and Evaluation of Refractory Nozzle Materials for Application to the High Altitude Supersonic Target Missile

摘要

Six high temperature nozzle throat materials were tested to evaluate their performance in a highly oxidizing rocket exhaust environment. Four nozzles were designed and fabricated with a throat inside diameter of approximately 1.47 inches. The materials tested in this configuration were pyrolytic graphite washers (edge-oriented), co-deposited silicon carbide/pyrolytic graphite (SiC/PG) coated on an ATJ graphite substrate, JTA composite graphitic material, and co-deposited Hafnium carbide/zirconium carbide/pyrolytic graphite (HfC/PG and ZrC/PG) washers. The best performance was demonstrated by the SiC/PG with an erosion rate of about 2 mils per second over a 35-second duration test. The remaining two nozzle materials, zirconium diboride (ZrB2) and pyrolytic graphite coated carbitex, were tested in a 2.55-inch nominal diameter throat nozzle. (Modified author abstract)