Influence of Deformation on Precipitation Behavior of 2024Al Alloy

In the present work, 2024Al alloy was rolled before solid solution, between solid solution and aging, and after aging treatments. Precipitation sequence in 2024 Al has not been altered by the rolling treatment. However, peak aging temperature of S’ phase was decreased from 264 to 254 oC, implying that the process of S’precipitation was accelerated by the deformation. After thermo-mechanical treatments, precipitates werefiner dispersed, and finest precipitate distribution was observed after treatment III (rolling between solid solution and aging), while precipitate size was all smaller than 240nm and more than 95% precipitates was smaller than 200nm. The highest dislocation density was found in 2024Al alloy after treatment III since the dislocations generated during deformation was slightly decreased during following low temperature aging treatment. Therefore, in order to improve the mechanical properties, it is suggested that the rolling treatment should be performed between solid solution and aging treatment.