Numerical and experimental investigation of a backward extrusion process for forming geared components from coil

Abstract

Abstract. Stricter political regulations, increasing ecological awareness of society as well as the pursuit for higher performance of components motivate lightweight construction. Functional integration is one way to realize lightweight design, resulting in increased demands on component geometry. Sheet-bulk metal forming (SBMF) offers the potential to enable an economic and ecological production of functional components through short process chains. SBMF from coil also provides additional advantages regarding high output quantity and short cycle times. However, the industrially application of SBMF from coil is limited due to high tool load and coil-specific challenges like an anisotropic material flow, which negatively affects the part accuracy. In this study, a backward extrusion process from coil for forming functional components with gearing is investigated. Therefore, a numerical process model was built and validated based on experimental results. In order to generate a profound process understanding, a combined numerical-experimental approach was chosen for a fundamental process analysis. The influence of the semi-finished product geometry was investigated by forming rotationally symmetric, pre-cut blanks and coil material. The application of the different sheet geometries was compared based on component- and process-side target quantities. The results indicate an anisotropic material flow as a coil-specific challenge, which leads to a direction-dependent component forming.