Abstract
The evolution of shear band and mechanical properties in plane strain compression of 7050- T7451 aluminum alloy were studied. The shear bands or slip lines formed on L plane with L direction constrained are more diffuse than those formed on T plane with T direction constrained. The constrained surface is rougher when it is L plane than T plane. The shear band formation is mainly in accord with the macroscopic mechanics approach. The flow strength of specimens with constraint in L direction is higher than that with constraint in T direction, except the final stage of true stress- engineering curve of specimen cut from surface and deformed with constrained in L direction. The specimens form trapezoid shape and decrease the true stress we measured. Compared with the tensile properties in previous study, shear bands formed at a strain near but a little bit larger than the uniform strain in tension. There is no obvious hardening phenomenon after formation of shear bands. The maximum and minimum points appeared in true stress- engineering strain curves of family II specimens are related to the formation of shear band. Regarding microstructure and texture in the alloy, when T direction was constrained, most slip bands fell into two sets which make an angle of 35°to the longitudinal direction on T plane of the specimen. On L plane of the specimens with constraint in L direction, most slip bands fell into two sets roughly follow the direction of the shear bands and make an angle about 90°. By X-ray diffraction, it is found that the texture in the alloy is mainly a mixture of Goss texture and Brass texture . Goss texture is the main texture to deform when constrained in T direction. Multiple slip occurs when the constraint is in L direction.