Microstructure and texture evolution in the cryorolled CuZr alloy

Abstract

The microstructure and texture evolution of the room temperature and cryogenically rolled Cu-0.3%Zr alloy were investigated at a range of true strains (0.36, 0.69, 1.20, 2.30) by transmission electron microscopy (TEM) and electron backscatter diffraction (EBSD). The high angle boundary spacing of lamellar grains along the normal direction is mainly dependent on the geometrical effect, and cryorolling has a minor refining effect on the width of the lamellae. However, the deformation twins and shear bands within the lamellar structure of the cryorolled CuZr alloy contribute to the grain refinement and improve the mechanical properties. The cryorolling enhances the inhomogeneous deformation and forms brass-type shear bands. In contrast to the copper-type texture in the room temperature rolled CuZr alloy, the cryorolled CuZr alloy exhibits a typical brass-type texture. This texture discrepancy is mainly attributed to the closely spaced twin/matrix lamellae and brass-type shear bands induced by cryorolling. The twin/matrix lamellae stimulate the initial formation of brass-type texture, and the shear bands promote its development. Unlike the room temperature rolled CuZr alloy, the Goss component is observed in the remnant grains in the cryorolled CuZr alloy. The occurrence of the Goss component may be attributed to the suppression of cross slip during cryorolling.