Finite element analysis of two-turn incremental ECAP

Ultrafine grained (UFG) metals produced by severe plastic deformation (SPD) are characterised by improved mechanical properties, which make them suitable for advanced applications. However, the practical uses of UFG metals are rare because of the lack of industrial methods of SPD. This paper describes a new SPD process of Incremental ECAP (I-ECAP) in the two-turn, S-shape channel version. While I-ECAP opens up a possibility of continuous processing of very long billets, it still involves numerous repetitions to accumulate a large plastic strain required for advanced structural changes. The two-turn version of this process doubles the amount of plastic strain generated in one operation and, therefore, improves process productivity. In order to check the feasibility of two-turn I-ECAP, a FEA simulation is carried out and the suitable tool geometry and process kinematics are established. The mode of material flow is the same as in the well established classical ECAP (route C) process, while continuous character and improved productivity suggest that the new process might be suitable for nanostructuring of metals on industrial scale.