FEM Method Study of the Advanced ECAP Die Channel and Tool Design

Equal-channel angular pressing (ECAP) is one of the most effective methods for obtaining ultrafine-grained structures in metals and alloys, significantly improving their mechanical properties. In this work, FEM modeling and development of a new design of the instrument for ECAP were carried out, followed by the production of real samples of working dies and casing. Four different designs of dies have been studied: with channel intersection angles of 90° and 45° and two schemes with the same angles and a spherical cavity to create back pressure. The main purpose of the study was to study the effect of dies geometry on the stress–strain state and pressing load, as well as to develop an optimal tool design that ensures the reliability and durability of the process. The simulation results showed that reducing the channel intersection angle to 45° increases the degree of accumulated deformation to 4.5 mm/mm but also increases the pressing load to 280 kN. The introduction of a spherical cavity contributes to a more uniform distribution of deformations, although the pressing load increases to 416 kN. Based on the data obtained, an improved tool design with a massive steel casing was developed and manufactured. The analysis and production of real samples confirmed its effectiveness and reliability, which will improve the ECAP process and obtain materials with improved characteristics while reducing operating costs.