Study On Texture And Mechanical Properties Of Cold Rolled AA 5052 Aluminum Alloy

The hot band of continuous cast (CC) AA 5052 aluminum alloy possesses a typical deformed structure and strongβfiber rolling texture. The mechanical properties of aluminium alloy sheets are strongly affected by heat treatments of hot bands and subsequent cold rolling. In the present work the evolution of texture and mechanical properties during cold rolling of AA 5052 aluminium alloy with and without pre-treatment was investigated by X-ray and tensile tests.The hot bands of CC AA 5052 aluminium alloy were annealed at 371℃for 3 hours, and then cold rolled to different reductions. The (111), (200), (220) and (311) pole figures were determined by X-ray diffraction in order to investigate the texture evolution of AA 5052 aluminium alloy during cold rolling. The orientation distribution functions (ODFs) were calculated from the incomplete pole figures using the series-expansion method. The texture volume fractions were calculated by an improved integration method. The results show that AA 5052 aluminium alloy exhibits the cube recrystallization texture after annealing at 371℃for 3 hours. As the cold-rolling reduction increases, the volume fractions of the cube, r-cube, r-Goss and remainder components decrease, whereas the volume fraction of theβfiber component increases. The relationship between the texture volume fractions and rolling true strain can be quantified by the Avrami equation.The hot bands and annealed hot bands of AA 5052 aluminium alloy were cold rolled to different reductions. The tensile properties of both cold rolled sheets were measured along the rolling direction. The strain hardening and orientation hardening/softening were analyzed based on the variation of the yield strength and Taylor factor with rolling true strain. The results show that yield strength and ultimate tensile strength of cold rolled sheets increase with increasing the cold rolling reduction, whereas elongation decreases for the hot band and annealed hot band of AA 5052 aluminium alloy. The relationship between the yield strength and rolling true strain can be represented by the Voce law. The contribution to the hardening rate of cold rolled sheets comes largely from the deformed microstructure and partly from the texture change. The orientation hardening occurs during cold rolling of the hot band. However, during cold rolling of the annealed hot band the orientation softening occurs at true strains below 0.5, while the orientation hardening occurs at true strains above 0.5.