MICROSTRUCTURE AND TEXTURE EVOLUTIONS OF AA1050 ALUMINUM ALLOY COLD ROLLED TO HIGH STRAINS

The evolutions of the microstructure and texture of AA1050 alloy cold rolled to large strains have been investigated using electron channeling contrast (ECC) imaging and electron backscattered diffraction (EBSD) techniques. It is found that the microstructure evolves from a cell--block structure at low strains into a lamellar structure at high strains, within which most of lamellar boundaries (LBs) are parallel to rolling direction (RD). Two mechanisms contribute to the microstructure transition, i.e., a gradual reorientation of the cell--block boundaries toward to RD due to the cold rolling deformation (Mechanism I, which is the dominant importance) and the realignment of boundaries to RD as a result of the shearing introduced by S--bands structure (Mechanism II). During this process a significant number of high angle boundaries (HABs) is created, about 47% HABs originate from deformation--induced boundaries at 90% reduction. The number of HABs increases and the spacing decreases with the increase of strains. The texture evolves into typical cold rolling deformation texture components of Brass+S+Copper, and the intensity of the texture increases with the increase of strain.