n this work the creep behavior and microstructure changes in aluminum single crystal during equal-channel angular pressing (ECAP) were investigated in order to understand the relationships between microstructure and creep behavior. The investigated crystal was oriented with {111} parallel to the shear plane and was parallel to the direction of shear. During ECAP by route A at room temperature single-crystalline sample was subsequently transformed into the polycrystalline material. Microstructure of samples processed by 1 and 4 ECAP passes was characterized by transmission electron microscope (TEM) and scanning electron microscope (SEM) equipped with the electron backscatter diffraction unit (EBSD). Microstructure analyses showed inhomogeneity of microstructure after ECAP and the increase in the fraction of of HAGB's (θ>15°) with increasing number of ECAP passes. Tensile creep tests at temperature of 373K and at applied stress of 50 MPa were performed on the Al single crystal after one and four ECAP passes. It was found that the creep behavior is influenced by cooperative grain boundary sliding along mesoscopic shear bands.
展开▼
