Influence of ultrasonic treatment on the structure of materials subject to intensive plastic deformation by radial-shear rolling

The subject of study comprises samples of M1 copper and copper alloys of the L63 and LZhMts66-4-7 grades obtained by radial-shear rolling. The patterns of formation of the structure and mechanical properties of ultrafine-grained copper and its alloys obtained by radial-shear rolling under ultrasonic treatment are established. The electron backscatter diffraction method is used to determine the orientations of individual grains, local texture, and identify phases in the samples under study. Local and general deformations, the number of recrystallized and deformed grains, their sizes and orientations are determined. The structure of ultrafine-grained materials and their mechanical properties are studied using X-ray diffraction analysis and scanning electron microscopy. The relationship between the parameters of ultrasonic action and the microstructure and physicomechanical properties of ultrafine-grained copper and brass samples is established. It is shown that ultrasonic action on materials after their radial-shear rolling at certain amplitudes of mechanical stresses promotes relaxation of the nonequilibrium structure of grain boundaries and, thus, the removal of internal stresses.