Investigation of cold extrusion process by coupled thermo-mechanical finite element analysis

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JOURNAL OF THE FACULTY OF ENGINEERING AND ARCHITECTURE OF GAZI UNIVERSITY, vol.35, no.1, pp.323-335, 2020 (SCI-Expanded) identifier identifier


As shown by Muller et al. [1] and Klocke [2], cold forward extrusion process which is widely used in the manufacturing of various parts in the industry is distinguished by its low material usage and improvesd mechanical strength due to strain hardening as well as manufacturing capabilities with narrow tolerances. Although extrusion process starts at room temperature, as stated by Groche et al. [3], the temperature on the workpiece can reach up to 200 degrees C and as reported by Groche et al. [4], the contact normal stress between die and workpiece can reach up to 3.000 MPa. Therefore, it is necessary to examine the temperature effects while conducting finite element analysis. It is known that, besides mechanical and physical properties of workpiece material, heat transfer between sample and die is also of high importance. However, there is no consensus about the magnitude of this heat transfer coefficient. This study examines the effect of the heat transfer coefficient between die and workpiece on the thermal and mechanical properties of the extrusion process using coupled thermo-mechanical finite element analysis. Finite element simulations are conducted using various heat transfer coefficients and forming speeds and differences in the results are discussed. Simulation results are verified through experiments.