The recrystallization processes of Al alloys under the influences of second–phase particles are investigated. There are many second phase particles in the microstructures of aluminum alloys. These second–phase particles can be formed in the solidification processes or precipitated in the solid phase transformation processes. They have great influences on the recrystallization processes of the Al alloys. Firstly

in the nucleation processes

the fine dispersed second phase particles prevent the dislocation movement

thus slowing down the recrystallization nucleation processes. However

when the sizes of the second–phase particles are large

the dislocations concentrate around the second– phase particles with high density

which leads to nucleation near the second phase particles. Secondly

in the process of recrystallization grain growth

the second–phase particles pin the grain boundary movement

thus slowing down the recrystallization processes. The influences of the size and distribution of second phase particles on the recrystallization processes are very important foundation of the composition and processing technology design of Al alloys. The influence factors of the second–phase particles on the recrystallization processes of Al alloys mainly focus on the analysis of the size and distribution of the second–phase particles. The morphologies of second–phase particles and the particle/matrix interfacial energies also have great influences on the recrystallization processes.