Evaluation of Deterioration Damage for Liquid Oxygen/Hydrogen Combustion Chamber of Copper Alloy by Replica Method for Oxide Film

抄録

Non-destructive damage evaluation of rocket engine combustion chambers was carried out using a replica method that employs a rapid-setting silicone rubber molding agent. Scratch marks, grinding marks and the oxide film on the combustion side surface that developed after repeated burning tests were successfully transferred to a silicone rubber sheet, eliminating any need for complex surface treatment before examination. The sampled replicas showed traces of oxide film formation and the disappearance of the grinding marks and crack formations on the oxide films caused by to redox reactions during repeated use. The surface roughness of the light and dark lines parallel to the cooling channels and cracked oxide film was evaluated by laser scanning microscopy. We found the surface roughness parameter to be potentially useful for evaluating the level of damage sustained by reusable sounding rocket engines.

 

This Paper was Originally Published in Japanese in J. Japan Inst. Met. Mater. 83 (2019) 176–180. Equation (2) and the captions of Figs. 1, 3, 4, 6, 7 were slightly changed.

Fig. 6 Macroscopic images of the sampled replica sheet show light and dark lines parallel to the cooling channels, the macroscopic image (a), the microscopic image (b), laser scanning microscope image of the light and dark line parts and the height measurement profile.