Incremental ECAP with converging billets

A new concept of incremental equal channel angular pressing (I-ECAP) with converging billets is proposed and simulated numerically. It follows a recently introduced process of ECAP with converging billets, in which the contact surface between converging billets plays the same role as a movable die wall in the output channel of classical ECAP and thus reduces friction and the process force. The process productivity is doubled and material pickup, especially problematic in the output channel, avoided. However, ECAP with converging billets, as any ECAP-based process, suffers from a limited length of the billets it can process. This paper proposes an incremental version of ECAP with converging billets, which enables processing very long billets. Additionally, a new option for ECAP or I-ECAP with converging billets is considered, which assumes their separation with a movable tool. This tool can also be used to apply a back force. FEM simulations of all these processes enable their comparison in terms of strain distribution and the force required.