Coperion is a leading global company for compounding, extrusion, metering and weighing technology as well as bulk materials handling. The hardening of the extrusion tools reduces the need for maintenance. Simulation helps to reduce residual stresses in designs in advance and to define the process parameters for the hardening process in the best possible way.
The main challenge here is to define the heating and cooling process in such a way that an optimum degree of hardness is achieved with low internal stresses and the best possible process parameters.
Setting up a workflow for the simulation of the residual stress on the tool and carrying out a transient temperature field analysis coupled with a structural mechanical investigation to determine the thermomechanical distortion with ANSYS Mechanical.
Through targeted comparative analyses, the tool design department was able to design prototypes in the best possible way in advance, thus saving cost-intensive development loops. A workflow defined with CADFEM made the entry into hardening simulation possible.
In order to minimize wear and tear and thus the need for maintenance of the equipment, great importance is attached to the hardening of the extrusion dies. The main challenge here is to define the heating and cooling process in such a way that an optimum degree of hardness is achieved. Due to the material transformation effects, thermomechanical internal stresses result in the components to be hardened during the cooling process, which can already lead to component damage during the hardening process. The simulation of the hardening process should help to design components with low residual stresses in advance and to define the process parameters for the hardening process in the best possible way.
With the knowledge gained from the simulation, Coperion is able, through targeted comparative analyses, to investigate the tool designs in the best possible way in the run-up to prototype production, thus saving cost-intensive development loops. By varying process and material parameters, the influence on the hardening result can be shown in a comparable manner. The findings from the pilot project were handed over to the customer in a subsequent training session together with the workflows implemented by CADFEM. This enabled Coperion to make an efficient start to the hardening simulation.
CADFEM supported Coperion's development department by implementing a workflow for simulating the internal stresses that arise in an injection head during the hardening process. For this purpose, a transient temperature field analysis coupled with a structural-mechanical investigation to determine the thermomechanical distortion was carried out with Ansys Mechanical®. Depending on the temperature-time curve, the elastoplastic material properties were adjusted in accordance with the underlying phase transformation properties during the simulation process (STAAZ method). The results of the analyses are the residual stresses and plastic strains at the end of the cooling process and a resulting hardness distribution in the component. Heavily stressed areas can be identified and constructively modified in order to minimize the risk of crack formation at an early stage.