Publications

In cooperation with Otto Fuchs KG, IPH is researching methods to predict and avoid thin flash during flashless forging of aluminum. The development of target-oriented sealing concepts should significantly increase process efficiency in the future.

flashless forging, aluminum, thin flash, sealing concept

3D printing of large mechanical engineering components with a unique character, such as ship gearbox housings, has great development potential as so-called additive manufacturing. As an alternative to casting with complex mold construction, additive manufacturing of such large products offers significantly greater design freedom. To this end, a consortium of research institutes and companies from Hanover, Langenhagen and Hamelin is jointly developing an XXL 3D printer with an installation space of 4.5 m * 3 m * 1.4 m. The printer will be used for the production of large parts.

Additive Manufacturing, 3D printing, XXL-products, Production of unique pieces, quality control

The production of hybrid components involves a long process chain, which leads to high investment costs even before machining. To increase process safety and process quality during finishing, it is necessary to provide information about the semi-finished parts geometry for the machining process and to identify defect components at an early stage. This paper presents an investigation to predict variations in dimension and cavities inside the material during cross-wedge rolling of shafts based on measured tool pressure. First, the process is investigated with respect to the variation in diameter for three roll gaps and two materials. Subsequently, features are generated from the hydraulic pressures of the tools and multi-linear regression models are developed in order to determine the resulting diameters of the shaft shoulder. These models show bet-ter prediction accuracy than models based on meta-data about set roll gap and formed material. The features are additionally used to successfully monitor the process with regard to the Mannesmann effect. Finally, a sensor concept for a new cross-wedge rolling machine to improve the prediction of the workpiece geometry and a new approach for monitoring machining processes of workpieces with dimensional variations are presented for upcoming studies.

Cross-Wedge Rolling, Forming, hybrid, tailored forming

Factory planning is an important tool for
manufacturing companies to raise their efficiency and to
maintain their competitiveness by changing market or
customer requirements. A special challenge is the acquisition
of layout data and the processing of this data in suitable
planning tools. Current approaches still measure manually
or have to transfer acquired data from laser scanners by
hand into planning tools, which leads to a high effort and
error proneness.
This paper presents a holistic concept for automated
and systematic data acquisition and processing for factory
planning processes.

3D factory planning, automated drone flight, point cloud processing, 3D layout scan

Warm forged components have better surface properties and higher dimensional accuracy than hot forged components. Diamond-like-carbon (DLC) coatings can be used as wear protection coatings, which are anti-adhesive and extremely hard (up to 3500 HV), to increase tool service life. In the first funding period of the research project at the IPH – Institut für Integrierte Produktion Hannover gGmbH and the Institute for Surface Technology (IOT) of the Technical University of Braunschweig in cooperation with the Fraunhofer Institute for Surface Engineering and Thin Films (IST), the influence of different coating types and process temperatures on tool wear was investigated. The result is, that DLC coatings can reduce tool wear in some cases significantly, but that their service life is strongly dependent on the temperature. Coating-integrated temperature measurement could not be realised at that point, due to adhesion challenges. During the second funding period, the effect of multilayer DLC coatings on tool wear was investigated. Also, an additional method of the temperature measurement on the engraving surface using thin film sensors was developed in order to correlate the local process temperature and local layer wear. In this work, the development of and the results gathered by the thin film temperature sensors are presented, which enable for more accurate temperature measurements than commonly used thermocouples. Their functionality and durability under high loads were investigated and showed to be promising.

DLC2, warm forging, forging, wear, forming

How can additive process chains be automated and print quality monitored? How is a component made of metal and plastic created in multi-material printing? Scientists from Lower Saxony ADDITIV have been researching this and more in the past three years.

additive manufacturing, 3d printing, automation, quality assurance

In this article, a method for automatic visual obstruction detection and mask-type congruent visual obstruction compensation, based on the principal of augmented reality, is presented. The method is based on the superposition of a simulated operator's field of view with information from a scene reconstructed by two RGB-Cameras. These cameras are arranged in a way that they can record the scene information behind the view restriction. Besides the presentation of the test rig, a detailed presentation of the image processing software is given. With a view to the later use of the system in a forklift truck, the real-time capability of the system will be tested and optimization possibilities will be discussed.

augmented reality, visual obstruction correction, forklift truck, image processing software

To be able to meet the challenges of globalization, the optimization of internal transport is becoming increasingly important. Due to the further development, drones are an innovative material handling technology. The use of drones can be cost-efficient, especially for time-critical transport tasks. However, drones are characterized by a very low payload and very high operating costs. Therefore drones are in some cases more economical than conventional means of transport, but they do not offer an universal solution for all internal transport tasks.

drones, intralogistics, transport, transport systems, economic efficiency

Automated guided vehicles are a crucial component for more efficient production systems in intralogistics, but they have weaknesses in human-machine interaction. Scientists at IPH are developing a gesture-based control system to make the interaction intuitive and increase its acceptance.

Driverless transport vehicles, guidance control, gesture-based control

The service life of rolling contacts is dependent on many factors. The choice of materials in particular has a major influence on when, for example, a ball bearing mayfail.Within an exemplary process chain for the production of hybrid high-performance components through tailored forming, hybrid solid components made of at least two different steel alloys are investigated. The aim is to create parts that have improved properties compared to monolithic parts of the same geometry. In orderto achievethis, several materials are joined prior to a forming operation. In this work, hybrid shafts created by either plasma(PTA)orlaser metal deposition (LMD-W) welding are formed via cross-wedge rolling(CWR)to investigate the resulting thickness of the material deposited in the area of the bearing seat. Additionally,finite element analysis (FEA)simulations of the CWRprocessare compared with experimental CWR results to validate the coating thickness estimation done via simulation. This allows for more accurate predictionsofthe cladding materialgeometry after CWR,and the desired welding seam geometrycan be selected by calculating the cladding thicknessvia CWR simulation.

Cross-Wedge Rolling, Forming, hybrid, tailored forming

In a research project at the Institute for Integrated Production in Hanover, the process parameters for cross-wedge rolling are to be determined with which an ultrafine microstructure can be achieved in cylindrical blanks. The aim is to achieve grain sizes of the rolled part in the range of 500 nm.

Process development, cross wedge rolling, material properties,Ultra fine microstructure

This paper presents concepts for shock and vibration reduction of a forging tongs. In the forging industry, hand-operated forging tongs are often used for the machining of forged parts. Here, the employees are exposed to high loads from shocks and vibrations of the forming machines. A simulation model that has been created evaluates concepts for reducing the shocks and vibrations during forging

Ergonomics, forging, shock and vibration reduction

Within the project "CoMoGear - Condition Monitoring of Marine Gearboxes based on Wireless, Energy-Autonomous Sensor Nodes", an energy-autonomous, wireless sensor network was developed for condition diagnosis of highly stressed rotating components in marine gearboxes was developed. This allows intelligent, condition-based monitoring and maintenance, paving the way for unmanned shipping.

sensor nodes, condition monitoring, marine gearbox, energy harvesting

Due to their design, the lift mast and attachments on industrial trucks, among other things, can restrict the operator's field of vision. In the project "Virtual visibility improvement and intuitive interaction through augmented reality on industrial trucks (Visier)", this situation is to be counteracted with the development of a new driver assistance system. With the aid of augmented reality (AR) goggles, the aim is to create the conditions for the driver to be able to block out visual restrictions and thus take a look behind the cargo and the mast in order to detect hazards and obstacles at an early stage.

Augmented Reality, assistance system, industrial trucks

In many companies, the demands placed on in-house processes is increasing in order to get the maximum benefit from available capacities. This includes, among other things, avoiding waste of internal capacity. With the optimization of route sheets by adapting the level of detail to the needs of production, a significant contribution can already be made during work preparation. Improving in the provision of information can have a positive impact on the efficiency of a company by reducing non-value-adding activities.

route sheets, work preparation, level of detail, provision of information, MES-implementation

A major challenge of logistics within manufacturing companies is the optimization of transport systems. Due to Industry 4.0, companies are more willing than ever to find and implement as yet unknown rationalization potential in this area. Currently, the use of drones in internal logistics is considered to have such potential. Especially when dealing with unplanned material transports for missing parts in assemblies or spare parts for repairs, the unmanned aerial vehicles could prove to be problem solvers. However, the use of drones is still a largely unexplored area, especially on factory floors.

drones, intralogistics, transport

To manufacture semi-finished hybrid workpieces with tailored properties, a finite element simulation assisted process chain design was investigated. This includes the process steps of cross wedge rolling, hot geometry inspection, induction hardening, and fatigue testing. The process chain allows the utilisation of material combinations such as high-strength steels with low-cost and easy to process steels. Here, plasma transferred arc welding is applied to supply the process chain with hybrid specimen featuring different steel grades. An overview of the numerical approaches to consider the various physical phenomena in each of the process steps is presented. The properties of the component behaviour were investigated via the finite element method (FEM) and theoretical approaches.

Cross-Wedge Rolling, Forming, hybrid, tailored forming

In this work we present an application of the virtual element method (VEM) to a forming process of hybrid metallic structures by cross-wedge rolling. The modeling of that process is embedded in a thermomechanical framework undergoing large deformations. Since forming processes include mostly huge displacements within a plastic regime, the difficulty of an accurate numerical treatment arises. VEM illustrates a stable, robust and quadratic convergence rate under extreme loading conditions in many fields of numerical mechanics. Numerically, the forming process is achieved by assigning time-dependent boundary conditions instead of modeling the contact mechanics yielding to a simplified formulation. Based on the two metallic combinations of steel and aluminum, different material properties are considered in the simulations. The purpose of this contribution is to illustrate the effectiveness of such a non-contact macroscopic framework by employing suitable boundary conditions within a virtual element scheme. A comparison with the classical finite element method (FEM) is performed to demonstrate the efficiency of the chosen approach. The numerical examples proposed in this work stem out from the DFG Collaborative Research Centre (CRC) 1153 “Process chain for the production of hybrid high-performance components through tailored forming”.

simulation, FEM, bulk metal forming, tailiored forming

Hybrid compound forging of aluminum bulk parts and steel sheet metals is a combination of material lightweight design and structural lightweight design. During this process, an aluminum bulk part and a steel sheet metal are combined and formed simultaneously. A material joint is generated by deforming, using zinc as solder material. This prevents the generation of brittle intermetallic Fe-Al-Phases as well as contact corrosion. The zinc layer is applied to the aluminum bulk part by hot dipping. To create a material locking connection by forming, suitable parameters such as the forming temperature are identified in first experimental trials. Microsections showed that the zinc layer is still intact after forming. In this paper the investigation of the effects of different steps of forming and different geometries of the aluminum bulk part surface on the joint strength are described. The forming tests show that a further forming of the aluminum part, resulting in a bigger deformation, leads to a stronger connection between both joining partners. But there is a limit to the forming since the applied forces can transfer to the steel sheet leading to an unintended deformation. The generated hybrid parts are tested for their ability for further forming. Therefore, the joined hybrid parts are undertaken a deep drawing process to see if the joint withstands further forming of the hybrid part.

aluminium, hybrid forging, lightweight construction, hybrid

If companies select a suitable transport system already during the factory planning stage, they can avoid subsequent adjustments and save a lot of time and costs. The IPH is developing a software demonstrator for automated layout and transport system planning.

factory planning, fuzzy logic, transport selection, routing

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