Thermo-Fluid Modeling of the Friction Extrusion Process

Abstract

Friction extrusion is a novel manufacturing process for producing high-value materials (e.g. metal wires) from low-cost precursors (e.g. powders) or through recycling of machining wastes (e.g. chips). In the friction extrusion process, the material experiences high temperature and severe plastic deformation before it forms the final product in the form of a wire. The present work is focused on understanding the heat transfer and material flow phenomena in the friction extrusion process. A numerical thermo-fluid model has been developed and validated by experimental measurements. In the model, the experimentally measured mechanical power is used as the heat input to predict the temperature field in the experiment. The processing material is treated as a non-Newtonian fluid with a viscosity that is temperature and strain rate dependent. Select marker particles in the material are followed and their motions observed in the simulation to study material flow patterns. It is found that predictions of the temperature field and marker particle trajectories match reasonably well with experimental measurements. Results of this study suggest that the proposed thermo-fluid model can capture the main features of the thermo-fluid phenomena in the friction extrusion process and can be used to provide reasonable predictions of the temperature and material flow fields in the friction extrusion process.