Prof. Dr. Marion Merklein
Chair of Manufacturing Technology

Prof. Dr. Marion Merklein
Chair of Manufacturing Technology

Research projects

  • Mechanical engineering with a focus on forming, joining by forming, material characterization and modeling, additive manufacturing and digitalization of production processes.
  • Hybrid additive manufacturing (AM and forming) for design of high strength, but light implants.
  •  As industrial areas automobile industry, transportation systems, construction work and bioengineering are of interest.

  • ME 2043/126-1: Development of a data driven method for the process design of thermally aided forming processes with additional component evaluation for hot stamping

    (Third Party Funds Single)

    Project leader:
    Term: 1. April 2026 - 31. March 2029
    Acronym: ME 2043/126-1
    Funding source: DFG-Einzelförderung / Sachbeihilfe (EIN-SBH)
    Abstract

    Thermally assisted forming processes, such as hot stamping, are technologically particularly demanding production processes with a large number of possible process parameter settings. The effects on the material properties in terms of process-structure-property relationships are not fully known. Process control based on classic methods for estimating material behavior with the aim of producing components with tailored material properties is only possible to a limited extent. The research approach is therefore based on the hypothesis that the synthesis of testing and characterization, modelling and simulation as well as new methods from the field of machine learning make it possible to establish new types of process-structure-property relationships. These in turn make it possible to generate efficient process models for process design and component evaluation in thermally assisted forming processes. The objectives of the project are to develop cause-effect relationships and to develop, apply and evaluate machine learning methods for the improved description of hot stamping processes with the following focal points: 1. a plant-related process model, which is used within the project for process design. The process model can be used to efficiently predict the microstructure and mechanical properties of the material (strength and hardness) at the end of the process for specified process parameters (thermal load path). The plant-related process model is therefore suitable for use in optimizing the process parameters with regard to the desired microstructure and associated properties in the process. 2. a hybrid material model for simulation-supported process design, which allows efficient FEM simulation of the entire hot forming process. The aim of the hybrid material model is to use the advantages of machine learning in material modelling where classical, physically motivated modelling has major challenges. Microstructural processes (such as austenitisation with subsequent quenching with different microstructural states, diffusive processes, phase transformations, etc.), which are very complicated from a physical modelling perspective, are leartned using experimental data. The methodology is developed and validated using the hot stamping process. The goal is to transfer the developed approaches to other materials, alloys and processes.

  • SFB/TRR 285 T07: Elaboration and qualification of a versatile process chain consisting of a pre-hole and joining process for industrial application (T07#)

    (Third Party Funds Group – Sub project)

    Overall project: Sonderforschungsbereich/Transregio 285 Methodenentwicklung zur mechanischen Fügbarkeit in wandlungsfähigen Prozessketten
    Project leader: ,
    Term: 1. January 2026 - 31. December 2027
    Acronym: SFB/TRR 285 T07
    Funding source: DFG / Sonderforschungsbereich / Transregio (SFB / TRR)
    Abstract

    The project comprises the elaboration and qualification of a versatile process chain for the mechanical joining of pin structures in a previously shear-cut pre-hole. The aim is to transfer scientific conclusions from project C01 to an industry-oriented process chain for the production of a bicycle cassette. The use of a crossover aluminum alloy developed by AMAG in this process chain is expected to make a significant contribution. The aim of the investigation is to identify the process limits and develop a process window for the design of load-appropriate joints.

  • Expansion of the joinability and improvement of the joint properties in mechanical joning processes by tailor heat treated aluminum semi-finished parts

    (Third Party Funds Single)

    Project leader: ,
    Term: 1. October 2025 - 30. September 2027
    Funding source: DFG-Einzelförderung / Sachbeihilfe (EIN-SBH)
    Abstract

    The increasing demands on the automotive industry to reduce the vehicle weight and to increase crash safety at the same time require the extensive use of modern high-performance materials as well as the production of car bodies with a multi-material design. This results in new challenges for joining technologies. This applies in particular to the joining of dissimilar, high-strength materials. Against this background, within the first phase of the project, the focus was to extend the process limits for shear-clinching high-strength aluminum alloys of the 7000 series by means of a tailored short-term heat treatment. The localization of the heat treatment enables the targeted setting of strength gradients in the sheet and thus the influencing of the material flow in the joining process with the aim of improving the properties of the joints. Within the second phase, the findings are to be transferred to joining with auxiliary joining parts. For this purpose, the investigations will be carried out using semi-tubular self-piercing riveting as an example. Furthermore, the control of the cooling rate during the retrogression of precipitation-hardenable aluminum makes it possible to influence the aging behavior and thus the resulting mechanical properties of the alloys. This circumstance is to be used to achieve not only an improvement of the joint geometry by the local heat treatment, but also to influence the resulting application properties by the complete control of the local temperature-time curves. With the aid of numerical simulation, the interaction between the heat treatment layout and the resulting material flow in the semi-tubular punch riveting process is investigated. After cold and artificial aging of the specimens, the resulting application properties are determined by varying the heat treatment layout and the realized cooling rate. In particular, the focus is on the strength under cyclic loading and the susceptibility of the alloy to stress corrosion cracking. It is known from the literature that retrogression followed by re-aging has a beneficial effect on corrosion behavior. The influence of such a heat treatment on the application properties of mechanical joining points is therefore to be analyzed as part of the research project.

  • 01|F23805N: Roll-formed profiles of high-strength aluminum alloys for semifinished products and complex component geometries (High-strength Al profile components)

    (Third Party Funds Single)

    Project leader:
    Term: 1. August 2025 - 31. July 2027
    Acronym: 01|F23805N
    Funding source: andere Förderorganisation
    URL: https://www.lft.fau.de/rollgeformte-geschlossene-profile-aus-hochfesten-aluminiumlegierungen-fuer-halbzeuge-und-komplexe-bauteilgeometrien-hochfeste-al-profilbauteile/
    Abstract

    As part of the IGF projecttitled "High-Strength Aluminium Profile Components – Roll-Formed, ClosedProfiles Made of High-Strength Aluminium Alloys for Semifinishe and ComplexComponent Geometries," an efficient process strategy is being developedfor producing complex component geometries from high-strength, closed aluminiumprofiles using hydroforming. The profiles are manufactured through roll formingand high-frequency induction welding, offering the advantage of a continuousproduction process and improved cost efficiency compared to traditionalextrusion methods. The project's objective is to implement this process chainfor high-strength aluminium alloys in the 6000 and 7000 series and to assessthe formability of the profiles—including the weld seam and the heat-affectedzone, which undergo microstructural changes—using IHU.

    Key scientific questionsconcern the formability and weldability of the alloys, the quality andmanufacturability of the weld seams, and the assessment of process-relatedmaterial properties through tube expansion testing. In addition toexperimentally investigating and optimizing individual process steps, theresults will be used to validate the simulation models of the entire processchain. An innovative aspect of the project involves managing input and outputparameters of the simulations via a centralized data platform. This platformenables statistical correlation and targeted optimization of processparameters, semi-finished product characteristics, and component quality. It isreferred to as a digital shadow, based on a simplified digital twin. Finally,the new process routes will be compared and evaluated against establishedmanufacturing methods from both economic and environmental perspectives,including the use of alloys with high recycled content. The goal is to supportresource-efficient and cost-effective production of high-strength,dimensionally stable lightweight profile components at scale.

  • Prediction of tool fatigue in cold forging processes

    (Third Party Funds Group – Sub project)

    Overall project: Prediction of tool fatigue in cold forging processes
    Project leader:
    Term: 1. April 2025 - 30. September 2027
    Funding source: Bayerische Forschungsstiftung
    Abstract

    Cold forging has been pioneering for more than 2000 years. In order toaddress current ecological and economic challenges and reduce CO2 emissions, technical components areprimarily produced using cold forging. This combines advantages such as theelimination of energy-intensive heat treatment and surface scaling. In order tomeet diverse requirements such as high load-bearing capacity and eco-friendlyproduction, the use of tools with complex internal geometries is necessary toenable the production of near-net-shape components. High contact pressures andtensile stresses due to high yield stresses lead to high loads on tools. Thiscan lead to fatigue failure, resulting in economic disadvantages that areassociated with an inhibition threshold for the use of efficient cold forgingprocesses.

    The goal of the project partners is to develop concepts forextending tool life of cold forging tools. Using numerical simulation models,it is possible to analyse tool loads in detail. To achieve this objective,geometric and mechanical component properties are analysed and used as adatabase for tool stress. Integrated into a simulation model, this data is usedto determine the tool life. In order to validate the accuracy of thepredictions, the methods are transferred to industrial processes.

    The calculation and subsequent extension of tool lifecontribute to more economical production of cold forged components and promotethe spread of eco-friendly manufacturing technologies in Bavaria as a businesslocation.

  • Mass-Presshärten: Improvement of the formability and joining strength of hot-formed, custom-made sheet metal semi-finished products

    (Third Party Funds Single)

    Project leader:
    Term: 1. December 2024 - 30. November 2027
    Acronym: Mass-Presshärten
    Funding source: AIF Arbeitsgemeinschaft industrieller Forschungsvereinigungen
    Abstract

    A key development objective in the automotive industry is the design of vehicle components to meet specific requirements whilst simultaneously reducing weight and thereby achieving fuel savings. In pursuit of these objectives, the use of press-hardened steels for the manufacture of safety-critical structural components has become established. Furthermore, the use of bespoke semi-finished products allows for targeted property grading whilst simultaneously saving material. These semi-finished products are produced, for example, by joining several sheets using resistance spot welding; the resulting composite can then be cold-formed. For this process, the semi-finished products require sufficient stability at elevated temperatures, as well as high formability, to ensure that the joint is not damaged during forming. As part of this project, the aim is to specifically adjust the number, geometry and position of the joints to ensure optimal load transfer between the joined components. To this end, resistance spot welds between different press-hardenable steels will first be characterised under press-hardening conditions. The type of load, forming temperature and holding time will be varied in a thermomechanical forming simulator. The knowledge generated in this process is then used to optimise the design of the joints using a simulation programme for metal forming and the specific load case. To verify the findings, geometrically complex demonstrators are then produced using the developed process strategy, and the knowledge gained is summarised in application-specific joining strategies, quality assurance criteria and design guidelines.

  • FORAnGen: Forming tailored hybrid semi-finished products - Tailored Additive Blanks

    (Third Party Funds Group – Sub project)

    Overall project: FORAnGen - Bavarian research association for the design of sustainable products using generative design
    Project leader:
    Term: 1. October 2024 - 30. September 2027
    Acronym: FORAnGen
    Funding source: Bayerische Forschungsstiftung
    Abstract

    The load-specific design of functional components is a promising way of responding to the increasing demands in terms of sustainability and resource efficiency. Tailored blanks have therefore become increasingly important in the field of sheet metal forming in recent years. The semi-finished product properties are customised to meet the final requirements. From an industrial perspective, it is of great interest to additionally increase the geometric flexibility and customisability of these tailored blanks by specifically combining forming technology methods with additive manufacturing. The technological advantages of the two processes complement each other perfectly and enable the efficient production of components with locally customised geometric and mechanical properties that clearly stand out from the state of the art. However, the interaction of the two processes under industry-related boundary conditions is still largely unknown.
    The aim of TP 3 is therefore to develop a holistic understanding of the material-efficient production and forming of customised, hybrid semi-finished sheet metal products. The integration of the hybrid manufacturing approach into generative design enables a continuous, economical product development process, which also allows the reduced CO2 footprint of the technology to be quantified by recording the process data in advance.

  • ME 2043/110-1: Investigations on the process combination of DED-LB/M and forming

    (Third Party Funds Single)

    Project leader:
    Term: 1. December 2023 - 30. September 2026
    Acronym: ME 2043/110-1
    Funding source: DFG-Einzelförderung / Sachbeihilfe (EIN-SBH)
    Abstract

    The primary aim of the research project is to develop a fundamental understanding of the process combination of DED-LB/M and forming with alternating application of the two steps. This can be used for future research to produce tailored components using DED-LB/M and forming. Due to the novelty of this approach, the project content relates to process control and, in particular, to the analysis of thermal and mechanical interactions in the application of the two manufacturing processes. One aim is to quantify the influences of different process strategies on the material properties as well as the temperature fields and profiles in DED-LB/M. In addition, the influence of the combination of the two processes on work hardening and mechanical properties will be analyzed. Based on this, the extent to which the strain hardening introduced during forming can be influenced by recovery or recrystallization during DED-LB/M will be investigated. In addition, the aim is to determine the relationships between the mechanical properties of the as-built test specimen, the formability and the resulting geometric component properties, also in alternating process sequences. This should generate a deep understanding of the forming behavior of structures manufactured using DED-LB/M, which can be used for the design of the combined production chain.

  • Data-based identification and prediction of the die surface condition and interactions in sheet bulk metal forming processes from coil

    (Third Party Funds Group – Sub project)

    Overall project: SPP 2422: Data-driven process modelling in metal forming technology
    Project leader:
    Term: 1. November 2023 - 31. October 2026
    Funding source: DFG / Schwerpunktprogramm (SPP)
    Abstract
    Manufacturing by forming offers the advantage of a material utilization of up to 100 %. Sheet bulk metal forming processes from coil can overcome current ecological and economic challenges through the efficient production of functionally integrated components. The production of defective components due to tool wear counteracts the high material utilization and thus reduces the energy efficiency. This results in increased product costs and environmental impact, as scrap costs have to be allocated to the good parts and defective components have to be disposed of and recycled. Online detection of signs of wear offers the potential to intervene in the process within a batch’s production and thus keep scrap levels low while positively influencing the environmental balance of the overall process. However, this requires a system that uses machine data in a knowledge model as part of an information model to predict tool wear and, thus, deviating component properties at an early stage. The aim of this research project is therefore to develop a tool wear model based on a full back extrusion process from the strip. Moreover, the correlation strengths between process parameters are to be determined from the automatic monitoring of the process by sensors, optical analysis and the microscopic examination of tool and component samples. These, in combination with a causal model constructed by experts, allow the generation of a quantified cause-effect graph. Additionally, experts may uncover previously unknown causal relations based on strongly correlated parameters that are validated experimentally and simulatively. The resulting quantified cause-effect graph is part of an information model formalized as an ontology, for product, process and the machine resource, including varying tools. With the help of an assistance system to be developed in the project, the information model can be interacted with in order to explain "backwards" observed deviations at product or tool by process variables acting on them and to predict "forwards" the effects of changes on dependent variables. Based on the extended parameter understanding, an intervention in the forming process within running batches and, thus, an increased resource efficiency shall be enabled.

  • Joining by forming of two-shear aluminum-steel-joints by shear-clinching

    (Third Party Funds Single)

    Project leader:
    Term: 1. July 2023 - 31. October 2026
    Funding source: DFG-Einzelförderung / Sachbeihilfe (EIN-SBH)
    Abstract
    Besides the use lightweight materials, the lightweight principle is realized by function integration and the load-specific design of components. This requires the joining of dissimilar materials as well as the joining of multi-layer sheets. Latter is a challenge, not only for welding technologies, but also for mechanical joining processes, since the additional sheet layer and contact surface obstructs the process design. Process limits of well-established mechanical joining processes also apply for the joining of multi-layer sheets. Therefore, high-strength material can only be joined with additional fasteners. Moreover, there are no systematic investigations on the influence of the mechanical properties of the joining partners, their thickness and the order for the joining by forming of multi-layer sheets. Therefore, the aim of the research project is the enhancement of process limits of joining by forming of dissimilar, multi-layer materials through the qualification of the shear-clinching technology for the joining of three-layer sheets. For this purpose, the shear-clinching process is fundamentally investigated for the joining of two-shear joints and the basic mechanisms are derived. The effect of the additional sheet is systematically analyzed in dependence of influences from the mechanical properties of the joining partners and the tool geometry. By the analysis of the cutting behavior and the material flow, the interaction of each layer is identified, laying the foundation for the adaption of prevailing tool systems for the changed process conditions. The suitability of the solution is confirmed by the analysis of the joint characteristics.

  • In-situ characterization of a locally carburized complex phase steel for manufacturing of tailored semi-finished products

    (Third Party Funds Single)

    Project leader:
    Term: 1. October 2021 - 31. March 2028
    Funding source: DFG-Einzelförderung / Sachbeihilfe (EIN-SBH)
    Abstract

    Hot stamping has established itself as a manufacturing process for safety-critical components. A further improvement in passenger safety can be achieved by locally adjusting the mechanical properties. This is based on the combination of high-strength zones for penetration protection in the interior and ductile zones, which enable energy absorption due to the higher residual deformation capacity. One method of tailoring is the local carburization of the semi-finished product. Due to the regional modification of the chemical composition, this process offers several advantages over welding- and temperature-based methods. For example, the design of the zones to be adjusted is very flexible due to the small transition areas. In addition, the process is independent of complex furnace and tool technology and is therefore particularly suitable for tailoring the properties of small series components. In addition to the strength-enhancing function of the additionally absorbed carbon, it also influences the phase transformation temperatures of the steel. This property is still uninvestigated in tailored carburization. Based on this effect, a greater gradation between carburized and non-carburized areas can be achieved by a suitable setting of the austenitizing temperature.
    The overall aim of the project is therefore to develop a fundamental scientific understanding of the process. Therefor, the influence of the carburizing parameters on the transformation temperatures is to be analyzed first. Based on this, a process corridor of the austenitization temperature can be identified as a function of the respective carburization. On the basis of this, the effect of varying the carburization parameters and the austenitization temperature on the mechanical properties of carburized and non-carburized samples will be investigated. The obtained results in combination with the in-situ characterization of the microstructural changes via laser ultrasound measurments will be used to identify a process window. In addition, the prediction accuracy of the numerical simulation is to be improved based on the in-situ characterization and the hot flow behavior, taking into account the process-specific influencing variables. The extended material models will be validated and verified using real demonstrator components. Furthermore, the demonstrator components, which have different carburized zones and were manufactured with various process parameters, are to be examined with regard to their energy absorption capacity using three-point bending tests and crash tests. Finally, a process evaluation and guidelines are to be derived with regard to the achievable grading using the method examined.

  • TRR 285 C01: Mechanical joining without auxiliary elements

    (Third Party Funds Group – Sub project)

    Overall project: Method development for mechanical joinability in versatile process chains
    Project leader: ,
    Term: 1. July 2019 - 30. June 2027
    Acronym: TRR 285 C01
    Funding source: DFG / Sonderforschungsbereich / Transregio (SFB / TRR)
    URL: https://trr285.uni-paderborn.de/
    Abstract

    Modernengineering structures increasingly rely on hybrid material systems in whichdifferent materials are combined according to their specific properties. Theresulting increase in material diversity places high demands on adaptable andresource-efficient joining technologies. Pin joining offers a novel approachfor creating robust joints between dissimilar materials without the need foradditional auxiliary joining elements.

    In pinjoining, metallic pins are locally formed directly from the base material byforward extrusion. These integral structural elements are subsequently used tojoin a counterpart material – within the scope of this project, eitheraluminium or fibre-reinforced polymers (FRP). Different joining strategies canbe applied: the formed pins may be pressed directly into the joining partner orinserted through pre-drilled holes and subsequently caulked. In both cases, acombined force- and form-fit joint is created, whose mechanical properties arestrongly influenced by the pin geometry, local material hardening, and theinteraction between pin and joining partner.

    The firstphase of the project focused on the fundamental investigation of single-pinjoints. The objective was to systematically analyse the underlying mechanismsand develop a comprehensive understanding of the relevant process–structurerelationships. To this end, manufacturing processes, achievable pin geometries,local material modifications, and load-bearing capacities as well as failuremechanisms were investigated experimentally. In addition, different processstrategies were evaluated with regard to their influence on joint quality andmechanical and geometrical properties.

    Thecurrently ongoing second phase transfers these findings to more complexmulti-pin joints. Particular emphasis is placed on the interactions betweenneighbouring pins and their influence on load transfer, stress distribution,and the overall load-bearing capacity of the joint. The aim is to establish aprofound understanding of pin interaction effects in order to enable the load-and material-specific design of multi-pin joints and to predict and tailortheir mechanical behaviour.

    Pin joiningtherefore offers considerable potential as a resource-efficient, adaptable, andauxiliary-element-free alternative to conventional joining technologies. Inparticular, the process opens up new opportunities for the realisation ofhigh-performance and sustainable hybrid lightweight structures.

  • CENEM: Center for Nanoanalysis and Electron Microscopy

    (FAU Funds)

    Project leader:
    Term: 1. January 2010 - 3. March 2038
    Acronym: CENEM
    Abstract
    The Center for Nanoanalysis and Electron Microscopy (CENEM) is a facility featuring cutting-edge instrumentation, techniques and expertise required for microscopic and analytical characterization of materials and devices down to the atomic scale. CENEM focuses on several complementary analysis techniques, which closely work together: Electron Microscopy, X-ray Microscopy, Cryo-TEM, Scattering Methods, Scanning Probes and Atom Probe Microscopy. With the combination of these methods new materials, particles, structures and devices are characterized not only microscopically and analytically on all length scales even down to the atomic scale but also by various in situ investigations and 3D methods. The knowledge gained through the versatile characterization methods is then used to further develop and improve materials and devices.

    CENEM was established in 2010 to provide a forefront research center for the versatile characterization of materials and devices with state-of-the-art instrumentation and expertise and to intensify the interdisciplinary research. The big CENEM network represents the strong collaborations within the University of Erlangen-Nürnberg as well as the collaboration with other universities, dedicated research institutes and industry.

    The support of the core facility CENEM by the German Science Foundation (DFG) and the Cluster of Excellence EXC 315 “Engineering of Advanced Materials” is gratefully acknowledged.

2026

2025

2024

2023

2022

2021

2020

Related Research Fields