Develop new ideas away from the desk: This is made possible by the creative space at the Institut für Integrierte Produktion Hannover (IPH) gGmbH. The retreat is intended to stimulate reflection and creativity, but also to facilitate teamwork.
creative space
The investigation of thin flash generation in a precision forging process of an aluminum long part using finite elements analysis (FEA) and corresponding forging trials is described in the presentation. Thin flash generation leads to bad handling and positioning in subsequent process steps and therefore tolerance defects. For investigation purpose, the forging processes were varied by use of different preforms with equal volumes but different mass distributions, while the geometrical parameters of the final part were not varied.
The forging processes were analyzed by FEA with focus on the value of the form-filling simultaneity depending on the preform geometry. Afterwards, corresponding forging trials were carried out for validation.The results of the experiments and the FEA showed good agreement concerning the part areas were thin flash generation was predicted by FEA and actually occurred in experiments.Preforms with higher values of form-filling simultaneity showed less thin flash generation while preforms with lower values of form-filling simultaneity showed significantly increased thin flash generation.
forging, flashless forging, aluminum, FEA, thin flash, prediction
To be able to forge undercut parts there is a need for an appropriate multidirectional forging tool. The main issue is the high required clamp force the tool must endure. Therefore two versions of the tool were designed. They differ in the closing mechanism for upper and lower die: one is form-fit, the other one is force-fit. An analyzation reveals that the force-fit version is more advantageous.
tool, design, forging, undercut, multidirectional
The generation of bulk metal forming processes needs a lot of time. Researchers construct and simulate many days until a forming sequence without defects is found. At IPH a algorithm is supposed to predict a simulation result within one minute based on the constructions made. The basis for the prediction are many simulations, which were set up, executed and analysed automatically. This article decribes one possible way of doing so.
KImulation, simulation, automation
Work-related illnesses and their results may pose a threat to businesses' productivity. This may as well affect businesses' competitiveness for the worse. A workplace designed by methods of ergonomic workplace-design may counter some of the caused issues. But companies often lack knowledge or fear required financial resources to restructure workplaces. With this article technical requirements to an automated ergonomics assesment system are described.
ergonomics, evaluation, optimization, workplace design
Marine gearboxes ensure the reliability of the entire ship. Therefore a timely maintenance is crucial. To decrease maintenance costs and increase security, IPH develops a wireless and energy-autonomous measurement system to monitor marine gearboxes from afar.
gearbox, ship, condition monitoring, maintenance
In order to improve the overall efficiency of production facilities through the use of automated guided vehicle systems (AGVs), the availability of the AGVs has to be high. Failures of AGVs have to be minimized. However, if a failure occurs, a successful disturbance management is crucial. Especially for producing companies, economic losses can occur, if material is not at the right place at the right time. Delays can be a hazard to the adherence to delivery dates. In this research project, a support system is developed that automatically generates strategies for the handling of disturbances.
AGV, expert system, automated guided vehicles, case-based reasoning, CBR
In the automotive industry, aluminum forged parts must fulfill lightweight and heavy duty performance requirements. The generation of thin flash between die halves and in the small gaps between the die and punch must be prevented during the flashless forging process in completely enclosed dies. However, thin flash formation is neither predictable nor preventable.
A numerical model is developed based on finite element analysis to investigate and predict the generation of thin flash in aluminum flashless precision forging processes. The significance and effects of the main influencing input parameters, including billet temperature, forming velocity, and width of gap, on different resulting parameters are evaluated. Among all resulting parameters in the established numerical model, hydrostatic pressure and the forming force in the main forming direction have been identified as the most suitable for predicting thin flash generation.
aluminum forging, forging in completely enclosed dies, flashless forging, FEA
Wind turbines can withstand more load changes than bridges or helicopters - but at some point they, too, have had their day. Operators of wind turbines should therefore consider their options for continued operation, repowering or complete dismantling before the end of the approved operating period. Together with practical partners, the Institut für Integrierte Produktion Hannover (IPH) gGmbH is researching how dismantling can be carried out quickly, cost-effectively and in an environmentally friendly manner. The project "Development of an impact model for the efficient design of dismantling networks for XXL products" is funded by the German Research Foundation (DFG).
dismantling, wind turbine
A combined measurement method for the optical determination of the absolute rotational angle and torque was realized. Absolute codings of the angle as well as proper production technologies for the production of suitable markings on the shaft were investigated and successfully implemented.
The absolute rotational angle could be measured with a resolution of about 0.001° at an accuracy of better than 0.2° (corresponds to 0.05% f. s.). Torque was determined with an accuracy of about 3% f. s..
The conclusion is that the overall aim was achieved.
optical measurement, torque, absolute angle of rotation
This lecture discusses the results of the research project "4.0 Ready", and goes into detail about the potentials and barriers of the implementation of interactive assistance systems, especially in the service and maintenance, as well as the support of the implementation by the use of maturity models.
industry 4.0, interactive assistance systems, data glasses, maturity models
Men and machines will soon be working side by side. Researchers at IPH contribute to this trend: They have developed a driverless forklift truck which understands human language and gestures.
Industry 4.0, logistics, autonomous transportation, AGV
High temperatures up to 1280 °C and high pressures during the forming opperation lead to strong tool wear in forging processes. Increasing tool wear can lead to very high costs. By experiments conducted at the Institut für Integrierte Produktion in Hanover the correlation between tool wear and lot size in hot forging processes was verfied. The findings will help companies to optimise maintenance procedures and therefore reduce cost in the future.
forging, steel, tool wear, lot size
A bus rebuilt as factory is presently touring across Lower Saxony and Bremen. The goal: getting small enterprises informed on Industry 4.0. The free roadshows are organized by "Mit uns digital!". Until the end of 2017, there will be another eleven tours.
industry 4.0, digitalization, SMEs
A low energy demand and a fast processing time are required in each industrial process for the production of crankshafts. Crankshafts have a very complex geometry and are forged with a high percentage of flash compared to other forging parts. Recent research showed the feasibility of a flashless forging of crankshafts. One way to forge a flashless crankshaft within three steps is to use cross wedge rolling, multi-directional forging and final forging.
This paper presents the investigation results of the influence of the cross section area reduction in cross wedge rolling on different parameters at multi-directional forging. First, the state of research, the process development and tool design of cross wedge rolling and multi-directional forging are described. Then a parameter study will be presented and the influence of the cross section area reduction on flash generation, billet temperatures, forming degree, forming forces and effective strain are shown. Generally, flash generates because a rotation-symmetric billet is forced into an asymmetric movement. The influence of an increasing cross section area reduction leads to a decreasing amount of flash at the bottom of the crankwebs.
multi-directional forging, cross wedge rolling, crankshaft, parameter study, forming angle
One research topic of the Institut für Integrierte Produktion Hannover (IPH) is the avoidance of worker overload in production during job shop scheduling to eliminate production errors, improve product quality and reduce cost.
job shop scheduling, human performance curve, error costs
"A different view of metal" is the title of the photo exhibition currently on display in East Frisia. The exhibition was organized by the Institute of Materials Science (IW) at Leibniz Universität Hannover. The pictures were taken by five metallographers from the Production Technology Centre Hannover (PZH).
A main target in automotive engineering research and development is currently to reduce fuel consumption and CO2 emissions. Therefore in this project lightweight design was combined with material design in order to produce more efficient structural components. The joining process for tubes of steel and aluminum by laser brazing was investigated to create a joint area that is highly formable. These steel-aluminum joints were afterwards hydroformed, at which steel and aluminum parts were formed in a single step. This process is called "IHU-THT" and can provide lightweight components with excellent mechanical properties.
FEA, hydro forming, tailored forming
Most of today’s technical parts and components are made of monolithic materials. These mono-material components produced in established production processes reach their limits due to their respective material characteristics. Thus, a significant increase in production quality and efficiency can only be achieved by combining different materials in one part. Bulk forming of previously joined semi-finished products to net shape hybrid components that consist of two different materials is a promising method to produce parts with locally optimized characteristics. This new production process chain offers a number of advantages compared to conventional manufacturing technologies. Examples are the production of specific load-adapted forged parts with a high level of material utilization, an improvement of the joining zone caused by the following forming process and an easy to implement joining process due to the simple geometries of the semi-finished products.
This paper describes the production process of hybrid steel parts, produced by combining a plasma-transferred arc deposition welding process with a subsequent cross wedge rolling process. This innovative process chain enables the production of hybrid parts. To evaluate the developed process chain, coating thickness of the billet is analysed before and after cross wedge rolling. It could be shown, that the forming process leads to an improvement of the coating, meaning a more homogeneous distribution along the main axis.
process chain, plasma-transferred arc deposition welding, hybrid parts, cross wedge rolling
Different challenges arise in cross wedge rolling hybrid parts depending of the material arrangement (serial or coaxial) which need to be investigated fundamentally first.
In cross wedge rolling of serial components, the controlled forming of the joining zone is the greatest challenge. The forming behaviour of the component halves is different, depending on the flow stress of the materials used. In order to allow the forming process to be carried out in a controlled manner, the forming behaviour was first analysed with regard to the displacement and quality of the joining zone, and then possibilities were determined with which the forming can be effected in a targeted manner. For this purpose, the influencing parameters (workpiece temperature, forming speed, cross-section reduction, shoulder and wedge angle) were determined systematically using the Finite Element method, and the investigations were then verified experimentally. In order to influence the forming behaviour the investigations include structural measures (e.g. unequal tool halves) as well as process-related parameters (e.g. unequal temperature distribution).
Cross wedge rolling of coaxial components has other challenges due to the component construction. The aim is to be able to specifically influence the course of the thickness of the applied coating during the forming. Therefore finite element simulations were carried out to determine the influencing parameters. By a systematic investigation of the test parameters according to the DoE method, the layer thickness before the deformation as well as the cross-section reduction are parameters with the greatest influences on the course of the layer thickness after the deformation gave. The results obtained were subsequently verified in experimental tests.
cross wedge rolling, steel, aluminum, joining zone, coating thickness
