Long-time aging behaviour of the alloy Al-2024 characterized by positron annihilation spectroscopy

The reconstruction of the precipitation structure after solution treatment has been investigated by positron annihilation spectroscopy. In this study the behaviour of samples taken from an aircraft "Airbus 300", being in oper ation for 18 years, is compared to a reference material supplied by Alcoa. The results of position annihilation spectroscopy show that there are no si gnificant differences in both materials. This finding is in agreement with the results obtained from other methods within the scope of the general res earch program which points to a materials behaviour as predicted for a safe operation of this type of aircraft.