Plenary Speakers

Marion Merklein

Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany

Pathways into a Sustainable Future – Research for Green Processes and Products

A. Hetzel, F. He, A. Horn, R. März, C.-M. Kuball, D. Römisch and J. Henneberg

In recent years, the growing customers’ demand for sustainable products as well as new governmental regulations to constantly decrease the amount of CO2-emission, have forced the manufacturing industry to seek for innovative technical solutions. Against this background, lightweight construction as well as resource-efficient processes have become a driving force to reach these ambitious goals. By substituting conventional steel grades with high-strength or ultra-high-strength steel, the overall weight and thus the energy consumption, e.g. for electrically powered vehicles, can be decreased. Beside the usage of lightweight components, sustainable processes, like hot stamping, forming of self-piercing rivets, innovative mechanical joining technologies or the usage of hybrid parts and digitalization, are other approaches to fulfil the growing demand of lower energy consumption and CO2-emission. However, the implementation of such processes as well as the manufacturing of the components requires a profound knowledge of the entire process chain. For this purpose, this plenary talk provides an overview of the state-of-the art, current investigations as well as future pathways to gain a sustainability by using the production technology. A special attention is also given to the recyclability of chip waste without energy-intensive meltdown processes and the usage of lubricant free deep drawing operations, since the demand for long-lasting green manufacturing solutions has constantly increased in recent years. For this purpose, current strategies are described and compared with respect to their potentials and disadvantages.

Matthew R Barnett

Deakin University, Institute for Frontier Materials, Geelong, Australia

Insights into metal forming via the microstructure

Metal forming impacts microstructure. This talk explores how microstructural characterization is shedding new light on metal deformation. Two challenges are considered. One, how to understand the elastic-plastic transition at the start of deformation and two, how to understand the deformation processes involved in high strain metal deposition in a relatively new solid state additive manufacturing process. In-situ Laue micro-diffraction at 25 Hz is used to gain insight into the former and electron backscattering diffraction is used to tease out the key deformation processes in the latter. With these techniques we see how the elastic-plastic transition is marked, in some cases, by distinct relaxation events that show up in sudden grain re-orientation. We propose some interpretations for their origin and how they might be incorporated into mathematical models. We also see that solid state metal deposition creates a distinct microstructure through a continuous process of dynamic recrystallization that permits attractive structures to be formed in the as-deposited condition.

Jeong Whan Yoon

1 Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
2 School of Engineering, Deakin University, 75 Pigdons Rd., Wauran Ponds, VIC, 3216, Australia

Challenges in Constitutive and Failure Modeling for Metal Forming

This paper reviews the currently popular approach to constitutive and failure modeling, focusing on the use of non‐associated flow rules to enable greater flexibility to capture the anisotropic yield and flow behavior of metals using less complex functions than those needed under associated flow to achieve that same level of fidelity to experiment, and on the use of path-independent spaces to more reliably predict failure limits under complex conditions of non‐linear forming. The paper discusses motivating factors and benefits in favor of both associated and non‐associated flow models for metal forming, including experimental, theoretical, and practical aspects. The paper also shows constitutive models to capture both anisotropic hardening response and Bauschinger effect. This review is followed by a discussion of the topic of the failure limits, the limitations of strain analysis, the evidence in favor of stress analysis, and the path-independent space to incorporate non-proportional loading paths for any ductile fracture models.