Effect of Deep Cryogenic Treatment on the Microstructure of an Aerospace Aluminum Alloy

This paper describes how deep cryogenic treatment at 98K produces changes in the microstructure of a heat-treated aluminum alloy. It was observed how the sub-micrometric particles increased near and at the grain boundaries. This slight precipitation did not produce any modification in static mechanical properties. However, the compressive residual stresses of the material were higher after compared to before the treatment. Both these effects can enhance the life of this alloy through cryogenic treatment.