Liquid oxygen compatibility of materials for space propulsion needs

Since the origin, the use of liquid oxygen as oxidizer is widespread in space propulsion. It has been the source of numerous incidents. Many materials can burn violently in an oxygen enriched environment when ignited. Consequently, it is mandatory to perform oxygen compatibility tests. In the present work, compatibility tests are impact tests and auto ignition tests. Both standardized test methods are illustrated by test results on polymeric materials (i.e. fluorinated resins, polyimides, polyetherketone) for seals and ball bearing cage. For future needs, in order to face the increase of pressure of injection of propellants in cryogenic engines, the adiabatic compression test has been identified as well suited for qualifying materials as oxygen compatible in highly constraining conditions. Details on the test procedure and on the installation available at the Université de Liège are presented.