Numerical Process Design for the Production of a Load-Adapted Hybrid Bearing Bushing

Abstract

Due to increasing product requirements regarding lightweight, functional integration and resource efficiency, research into and use of hybrid parts are steadily increasing. Tailored Forming provides an innovative process chain for manufacturing hybrid parts by using pre-joined semi-finished products. In addition to the potentials, however, challenges also result in the production of hybrid components. In particular, the material combination of steel and aluminium is demanding due to strongly differing physical properties. An inhomogeneous temperature distribution within the pre-joined semi-finished part can be used to equalize flow properties during the forming process. However, processes are sensitive to temperature deviations resulting in critical stresses and failure of the final part. This study focuses on a process design of a hybrid bearing bushing consisting of the aluminium alloy EN-AW-6082 and the steel 100Cr6 using numerical simulation. First, a closed-die forging process is analysed regarding sensitivity to process fluctuations resulting in deviations in temperature distribution. To increase process stability, a new hollow forward-impact extrusion process is numerically designed and investigated regarding its potential to reduce critical stresses and thus the risk of part failure. Furthermore, a numerical model of inductive heating is used for the consideration of inhomogeneous temperature fields. Finally, hybrid bearing bushings are produced using closed-die forging and hollow-forward extrusion to evaluate numerical results.