Recrystallization and Grain Growth Phenomena in a Particle-Reinforced Aluminum Composite

摘要

Recrystallization and grain growth in a 2219/TiC/15p composite were investigated as functions of the amount of deformation and deformation temperature. Both cold and hot deformed samples were annealed at the normal solution treatment temperature of 535 deg C. It was shown that large rystallized grain diameters, relative to the interparticle spacing, could be produced in a narrow range of deformation for samples cold-worked and those hot-worked below 450 deg C. For cold-worked samples, between 4 to 6 pet deformation, the recrystallized grain diameters varied from 530 to 66 mu m as the amount of deformation increased. Subsequent grain growth was not observed in these recrystallized materials and noncompact grain shapes were observed. For deformations greater than 15 pet, recrystallized grain diameters less than the interparticle spacing were observed and subsequent grain growth produced a pinned grain diameter of 27 mu m. The pinned grain diameter agreed well with an empirical model based on three dimensional (3-D) Monte Carlo simulations of grain growth and particle pinning in a two-phase material. Tensile properties were determined as a function of grain size, and it was shown that grain size had a weak influence on yield strength. A maximum in the yield strength was observed at a grain size larger than the normal grain growth and particle-pinned diameter.