Effect of Concurrent Precipitation on Recrystallization and Evolution of the P-Texture Component in a Commercial Al-Mn Alloy

The recrystallization behavior of a cold-rolled Al-Mn alloy was investigated, focusing on the effect of concurrent precipitation on nucleation and growth of recrystallization and the formation of the P- ({011}< 111 > and ND-rotated cube ({001}< 310 > texture components. It was observed that if precipitation took place prior to or simultaneously with recovery and recrystallization processes, i.e., by concurrent precipitation, this resulted in a delayed recrystallization, a coarse and elongated grain structure, and an unusually sharp P- texture component. The P- texture component sharpened with increasing initial cold rolling reduction, increasing initial supersaturation of Mn, and decreasing annealing temperature. The P- and ND-rotated cube nucleation sites have an initial growth advantage compared to the particle-stimulated nucleation (PSN) sites due to their 40 deg < 111 >-rotation relationship to the Cu component of the deformation texture. The boundaries between such sites and the surrounding matrix will be of the Sigma 7 type, and it is assumed that such highly perfect boundaries will be less affected by solute segregation and precipitation, resulting in early growth advantage. It was further observed that dispersoids present prior to cold rolling and annealing had a weaker effect on the recrystallized grain size and texture compared to concurrent precipitation, even though the average dispersoid density was higher in the pre-precipitation cases. The finer grain size was explained by the wider dispersoid free zones surrounding the large constituent particles compared to the concurrent precipitation cases. Subsequent growth of the nucleated grains, however, was more hindered due to the Zener drag, consistent with the higher dispersoid densities.