Texture evolution during equal channel angular extrusion: Part I. Effect of route, number of passes and initial texture

It is shown that equal channel angular extrusion (ECAE) is an effective technique to control texture of metals and alloys. Two processing parameters, the route and number of passes, exert an important influence on texture evolution. Routes define orientations allowing the creation of numerous new components. Before four passes, depending on route and initial texture strength, all types of texture strength, from weak to very strong, are created, whereas after four passes, a global texture weakening is observed for all routes and medium to strong to very weak textures are produced. A simple Taylor model shows that crystallographic slip mechanically activated by simple shear is the governing mechanism for evolution of texture orientations. However, after four passes, the creation of submicron-grained structures with high misorientations is believed to limit crystallographic slip and weaken textures.