TESTING METHOD OF GRAPHITE MATERIAL FOR NOZZLE OF ROCKET MOTOR

摘要

PURPOSE:To evaluate quantitatively the thermal shock resistance of graphite material for a nozzle by deriving the limit thermal shock speed of a solid model by using a shape correcting factor and a limit thermal shock speed derived from a limit electric power value where a cracking occurs to a graphite disk. CONSTITUTION:The graphite disk 1 to be tested is mounted between graphite electrodes 2 and 3 for arc discharge at specific intervals and a high voltage is applied from a power source adjusting device 11 to measure the limit electric power value W0 where cracking occurs to the disk 1, and the limit thermal shock speed of the disk is derived from a specific expression. Similarly, the limit electric power value E0' of a small-sized graphite solid model similar to the nozzle of a rocket motor is derived, and those two electric power values are compared mutually to obtain a shape correcting factor. The electric power value W0' is multiplied by the factor to device the limit thermal shock speed of the solid body. Thus, the thermal shock resistance of the graphite material for the nozzle is evaluated quantitatively and accurately with ease.