Evolution of the AA2030 alloy microstructure in the ECAP process.

This work aims to study the microstructural development of lead-containing aluminum alloy in the process of intense plastic deformation. The evolution of the AA2030 alloy obtained by the ECAP and long-term natural aging (within 45 months) has been analyzed using electron microscopes. The average grain size of the ECAP treated samples is 420 and 380 nm along the routes B_c and C, respectively. Long-term natural aging contributes to transforming grain boundaries without changing their size. The results have shown that the structure, phase distribution, and stoichiometric composition of the inclusions differ significantly during annealing, equal-channel angular pressing, and long-term natural aging. The strain route affects the dissolution kinetics and evolution of inclusions. A mechanism for refining the grains is proposed that is associated with high dislocation density, dislocation cells, grain and subgrain boundaries, as well as the evolution of inclusions in the ECAP AA2030 alloys. [ABSTRACT FROM AUTHOR]