Insights into the Mechanical Properties and Correlation Between Strain Path and Crystallographic Texture of the AA2024 Alloy During Severe Plastic Deformation

Abstract

This study examined mechanical properties of AA2024 alloy and its correlation between strain path and crystallographic texture. Accumulative roll bonding (ARB) and cross accumulative roll bonding (CARB) were used to severely deform AA2024 alloys. Electron backscatter diffraction (EBSD) studies demonstrated that nano/ultrafine grains were formed by the strain routes after eight cycles. It was also found that the lamellar boundary spacing and the mean boundary spacing were ~ 360 ± 10 nm and 845 ± 10 nm after eight ARB cycles. In contrast to the ARB, the CARB specimen had equiaxed microstructures characterized by grains with a size of 150 and 100 nm. The CARB processed specimen exhibited a mean misorientation angle of 41.83° and a fraction of high angle grain boundaries of 78%, these values were 34.57° and 67% for ARB treated specimen, respectively. It was observed that the evolved texture is greatly affected by the strain paths. The ARB processed specimen revealed strong Copper {112} <111>, Dillamor {4 4 11} <11 11 8>, S {123} <634>, and Brass {011} <211> components. In contrast, the CARB processed specimen showed major texture with prominent Copper {112} <111>, Brass {011} <211>, Rotated Cube {001} <110>, S {123} <634>, and Goss {011} <100> components. In the CARB specimen, the Goss/Brass texture ratio was intensified and the mechanical properties were superior (tensile strength: 535 MPa, microhardness: 182 HV, elongation: 11.9%) compared with the ARB processed specimen (tensile strength: 455 MPa, microhardness: 145 HV, elongation: 9.2%). Further, the change in strain path did not significantly affect the intensity of Goss and Cube components, ruling out any further recrystallization tendency.

Graphical Abstract