Use of aluminum-beryllium composites on the orbcomm~sm satellite

摘要

Newly developed metal matrix composites of aluminum and beryllium have been used n the primary structure of Orbital Sciences Corporation's ORBCOMM comunication satellites. Hot isostatically pressed and extruded AL-Be allys used in these spacecraft have a two-phase microstructure that combines the stiffness and light-weight of beryllium with the ductility and fabrication ease of aluminum and the synergistic strengthening effect of the dual phases. The ORBCOMM spacecraft has undergone a rigorous qualification testing program that included model identification (to verify structural stiffness), ultimate static loading, vibration testing to levels typical of a pegasus launch, separtion shock loading to over 600 g's at greater than 1000 Hz, and thermal cycling between - 35 deg C and + 40 deg C. The aluminum-beryllium composite structure survived these environments with no cracking. no detrimental permanent deformation, and no degradation in material properties. Furthermore, the first two ORBCOMM satellites have been launched into low earth orbit by OSC's Pegasus launch vehicle, and have bene operating for over a year. This paper will furthe rdescreibe the spacecraft structure, design drivers that led to the selection of this material, its fabrication process, results of qualification testing, and a ocst comparison to other materials.