Study on quasi-in-situ tensile microstructure evolution law of 5052-O aluminum alloy based on EBSD

Abstract

SHIMADZU AGS-100KN universal testing machine was used to carry out tensile experiments of 2.2%, 5%, 10%, 15%, 20% and 25% of different tensile elongations on 5052-O aluminum alloy. The surface DIC morphology characteristics and the evolution law of the microstructure of samples under different elongation rates were studied by the DIC (digital image correlation) and the EBSD (electron backscatter diffraction). The results show that the tensile strength of the 5052-O aluminum alloy reaches the maximum value of 205.632 MPa and the elongation at failure is 28.8%. When the tensile deformation is 2.2%, there is an obvious slip band at 45° to the direction of the tensile axis. At 10% deformation, the slip band is obviously narrowed, with darker interior color and large deformation. With the gradual increase of the deformation, the proportion of the microstructure recrystallization area and the substructure area decreases, and the proportion of the deformation area increases. The plastic deformation mechanism is mainly the dislocation slip. The low angle grain boundary gradually increases and the high angle grain boundary decreases as the increase of deformation. When the deformation is above 15%, the changing trend of low-angle and high-angle grain boundaries also slows down. During the tensile deformation process, the corresponding KAM (Kernel Average Misorientation) value distribution curve value is constantly moving to the right and expanding. The R-type texture {124}< 211 > always exists, the Brass texture {110}< 112 > and the S-type texture {123}< 634 > keep increasing. • During the quasi-in-situ tensile test of the 5052-O aluminum alloy sample, the change of the sample morphology was continuously recorded by DIC. It can dynamically observe the microstructure changes of the specimen during the tensile process. • EBSD was used to study the evolution of grain orientation, the change of recrystallization region and the statistics of crystallographic orientation difference of specimens under different deformations during tensile deformation. It reveals the stress concentration mechanism in the deformation region and discusses the evolution of texture after tensile deformation. It provides some theoretical basis for the process optimization in industrial production. • Through the analysis of the texture evolution, the R-type texture {124}< 211 > existed during the deformation process. The Brass texture {110}< 112 > and S-type texture {123}< 634 > continued to increase with the tensile deformation increased.