Orientation Preference of Recrystallization in Supersaturated Aluminum Alloys Influenced by Concurrent Precipitation

The influence of concurrent precipitation on recrystallization is analyzed by comparing the nucleation and growth behavior of P ({011} 〈566〉), Cube ({001} 〈100〉), and 20 deg ND-rotated Cube ({001} 〈310〉, NDcube)-oriented grains in Al-xMn-Fe-Si (x = 0, 0.4, 1.0 wt pct) alloys. The number densities of recrystallized grains in alloys annealed at various temperatures clearly demonstrate that concurrent precipitation significantly reduces the nucleation density of recrystallization. However, this effect varies strongly with grain orientation, and the P orientation is affected less than other orientations, in particular the Cube orientation. The number fraction of P-oriented grains can increase ten times as the effect of concurrent precipitation enhances. The P- and NDcube-oriented grains grow faster than Cube grains when strong concurrent precipitation occurs. However, on the other hand, when precipitation is limited or completely absent, P grains grow more slowly than Cube (and NDcube) grains. Micro-segregation enhances the effect of concurrent precipitation, indicating that the effect is closely related to heterogeneous distribution of precipitation.