Improvement in Strength of 2024 Al Alloy by Enhanced Solution Treatment

摘要

In this paper the effects of an enhanced solution and aging on the strengthening behavior of commercially available 2024Al alloy were investigated using tension testing and scanning electron microscopy. A differential scanning calorimeter (DSC) was used to measure the incipient melting behavior and then determine the technological parameter of an enhanced solution heat treatment for strengthening the 2024Al alloy. The results show that the incipient melting behavior of the commercially available 2024Al alloy was characterized by a small amount of liquid phase between the temperatures 773K to 788K. A solution treatment, appropriately enhanced by slowly increasing the solution temperature from 773K to 783K at a heating rate of 5K/h, can make the final solution temperature of the alloy higher than the conventional solution temperature of 773K. This improves the constituent phase solution without the formation of overheated microstructures. The results are the strength, especially the yield strength, and the resistance to over-aging can both be considerably improved without a large deterioration to tensile ductility.