(V) Influence of TiB2 particles on the recrystallization and grain growth of aluminum alloys

With particles in the alloy, the recrystallization and grain growth are usually hindered. Large particles can also promote recrystallization in severely deformed area around them. For in-situ TiB₂ reinforced aluminum alloy, the size of TiB₂ particles inside distributes from tens of nanometer to a few micrometers, result in complicated influence during annealing. Detailed influences of TiB₂ particles on recrystallization and grain growth are analyzed with the help of different annealing processes. During recrystallization, TiB₂ particles are difficult to impede the grain boundary migration and the large ones can randomize the recrystallized texture by particle simulated nucleation. In the period of grain growth, TiB₂ particles are only effective in pinning on grain boundaries with misorientation angles out of the range of 20~45˚. Grain boundary energy has a greater impact on the grain growth than the pinning force of TiB₂ particles.