STATIC RECRYSTALLIZATION BEHAVIOR OF A SiC - PARTICLE REINFORCED ALUMINUM ALLOY AFTER HOT DEFORMATION

Static recrystallization (SRX) behavior of a composite based 7075 Aluminum alloy reinforced with SiC particles was studied during annealing the deformed samples at high temperatures. The results showed an absence ofSRX in the samples annealed after hot working at the same deformation temperature, however, a rise in annealing temperature of100-1500 Cabove that the def ormation temperature led to f ull recrystallization. This can be ascribed to the relatively moderate dynamic recovery and the presence of dispersions which stabilize the substructure. Particle stimulated nucleation (PSN) had a significant effect on the grain size in deformed samples at low temperature, but no PSN was observed in samples strained at high temperatures. The possible cause might be that at high temperature the dislocations can be annihilated by climb process around the particles together with the absence of deformation zone for nucleating the recrystallization.