Process Optimization through Thin Flash Prevention. Due to the good flow properties of aluminum, the material tends to flow into tool gaps during flashless precision forging and produce the so-called thin flash. For the industrial implementation of flashless precision forging processes, an innovative prediction method for thin flash as well as sealing concepts are to be developed in cooperation with an industrial partner. Simulative studies show that local form filling does not correlate with high pressure or an increased potential for thin flash.
thin flash, FEM-simulation, sealing concepts, precision forging, forming technology
Progressive digitalization and new technologies have had a major impact on the development of artificial intelligence (AI) in recent years. Particularly for companies in the skilled trades sector, the time factor is taking on an increasingly changing customer behavior, more complex and demanding tasks, and other challenges, the time factor is playing an increasingly decisive role.
artificial intelligence, craft, guideline
A new process chain for the manufacturing of load-adapted hybrid components is presented. The "Tailored Forming” process chain consists of a deposition welding process, hot forming, machining and an optional heat treatment. This paper focuses on the combination of laser hot-wire cladding with subsequent hot forming to produce hybrid components. The applicability is investigated for different material combinations and component geometries, e.g. a shaft with a bearing seat or a bevel gear. Austenitic stainless steel AISI 316L and martensitic valve steel AISI HNV3 are used as cladding materials, mild steel AISI 1022M and case hardening steel AISI 5120 are used as base materials. The resulting component properties after laser hot-wire cladding and hot forming such as hardness, microstructure and residual stress state are presented. In the cladding and the heat-affected zone, the hot forming process causes a transformation from a welding microstructure to a fine-grained forming microstructure. Hot forming significantly affects the residual stress state in the cladding the resulting residual stress state depends on the material combination.
laser hot-wire cladding, cladding, hot forming, residual stress, tailored forming
Geometry, design, and processing in addition to the thermoelectric material properties have a significant influence on the economic efficiency and performance of thermoelectric generators (TEGs). While conventional BULK TEGs are elaborate to manufacture and allow only limited variations in geometry, printed TEGs are often restricted in their application and processing temperature due to the use of organic materials. In this work, a proof-of-concept for fabricating modular, customizable, and temperature-stable TEGs is demonstrated by applying an alternative laser process. For this purpose, low temperature cofired ceramics substrates were coated over a large area, freely structured and cut without masks by a laser and sintered to a solid structure in a single optimized thermal post-processing. A scalable design with complex geometry and large cooling surface for application on a hot shaft was realized to prove feasibility.
thermoelectric, printed electronic, laser structuring, printed ceramics, spray coating
The digital development of spaces within the city of Hannover by means of a digital image makes it possible to cover the usage needs of spaces more efficiently and in line with the requirements. The crea-tion of a digital image, which develops new possibilities for access to public space, requires the use of different sensors such as LiDAR sensors and tracking cameras. In order to select suitable sensors that can be used with UAS, the requirements for the overall system are first defined, which are derived in functional requirements for the sensor technology. Subsequently, the degree of fulfilment of the functional requirements by the different sensors
5G, UAS, digital image, digital twin
In the non-circular rolling, the feasibility of rolling several mutually offset, locally non-round shaped elements into a cylindrical semi-finished product are investigated. One sub-area of the investigations is the rolling of two elliptical sections.
From three different calculation concepts for the determination of the tool engraving, one was chosen for a simulative parameter study. The main influencing variables, including the length and width of the engraving and a process window, were identified.
forming technology, manufacturing technology, FEM
In order to use laser transmission welding (LTW) for additively manufactured parts such as prototypes, small series, or one-off products, an enhanced process knowledge is needed to overcome the difficulties in the part composition resulting from the additive manufacturing process itself. In comparison to an injection molding process for thermoplastic parts, the additive manufacturing process fused deposition modeling leads to an inhomogeneous structure with trapped air inside the volume.
In this paper, a neural network-based expert system is presented that provides the user with process knowledge in order to improve the weld seam quality of laser welded additively manufactured parts. Both additive manufacturing and LTW process are assisted by the expert system. First, the designed expert system supports the user in setting up the additive manufacturing process to increase the transmissivity. During welding, the additive manufacturing and LTW process parameters are used to predict the weld seam strength. To create the database for the expert system, specimens of transparent and black polylactide are additively manufactured. In order to change the transmissivity at an emission wavelength of 940?nm of the diode laser used, the manufacturing parameters for the transparent parts are varied. The transmissivity of the parts is measured with a spectroscope. The transparent samples are welded to the black samples with laser powers between 8 and 14?W in the overlap configuration and shear tensile tests are performed. In this work, the predictions of the transmissivity and the shear tensile force are demonstrated with an accuracy of more than 88.1% of the neural networks used for the expert system.
Additive manufacturing, laser transmission welding, neural networks, expert system
In order to make the production of complex geometries as efficient as possible, several forming stages are generally used. In these, the billet is first heated homogeneously and then forged via several preliminary and intermediate stages as well as final forming. Previous investigations have shown that significant material savings can be achieved by using inhomogeneous, rather than homogeneous, billet heating. A limiting factor in the practical implementation of inhomogeneous heating is the temperature gradient between the hot and warm regions of the billet.
This study therefore investigates the influence of the length of the temperature gradient on the blank size required to achieve form filling for a given finished part geometry. For this purpose, a simulative parameter study was carried out with three temperature transitions of different lengths and two different finished part sizes.
It was shown that, depending on the finished part size and the length of the temperature gradient, between 3.31% and 17.49% material can be saved compared to a homogeneously heated billet. The length of the temperature gradient thus has a significant influence on the material savings potential.
bulk forming, inhomogeneous heating, resource efficiency, FEA
The temporally and spatially accurate display of information in augmented reality (AR) systems is essential for immersion and operational reliability when using the technology. We developed an assistant system using a head-mounted display (HMD) to hide visual restrictions on forklifts. We propose a method to evaluate the accuracy and latency of AR systems using HMD. For measuring accuracy, we compare the deviation between real and virtual markers. For latency measurement, we count the frame difference between real and virtual events. We present the influence of different system parameters and dynamics on latency and overlay accuracy.
augmented reality, image processing, driver assistance system, forklift trucks
Additive manufacturing enables the economical production of complex components with a high degree of customization. Therefore, the medical industry is using the advantages of additive manufacturing to produce individualized medical devices. Medical devices are subject to special quality control requirements that additive manufacturing processes do not meet yet. This article deals with the introduction of an in situ process monitoring concept using the example of fused deposition modeling. The process monitoring is carried out by a quality model, which accesses the data of a self-developed sensor concept integrated in the printer. This data is analyzed using a machine learning pipeline to predict process and product quality. Thereby, the machine learning pipeline consist of several sequential steps, ranging from data extraction and preprocessing to model training and deployment. The procedure presented for ensuring print quality forms a basis for the production of safety-relevant components in batch size one and extends conventional quality assurance methods in additive manufacturing.
additive manufacturing, quality monitoring, fused deposition modeling, artificial intelligence
Process monitoring strategies allow wear-related conditions of forging dies to be detected and predicted. The prediction of the wear condition allows intelligent maintenance strategies. This allows residual tool life to be fully utilized, scrap to be reduced and downtime to be calculated. The content of this article is an economic analysis for calculating the payback period of a process monitoring system.
forging, process monitoring, economic efficiency
Laser transmission welding (LTW) is a known technique to join conventionally produced thermoplastic parts, e.g. injected molded parts. When using LTW for additively manufactured parts (usually prototypes, small series), this technique has to be evolved to overcome the difficulties in the part composition resulted in the additive manufacturing process itself.
In this paper, a method is presented to enhance the weld seam quality of laser welded additively manufactured parts assisted by a neural network-based expert system. To validate the expert system, specimens are additively manufactured from polylactide. The parameters of the additive manufacturing process, the transmissivity, and the LTW process parameters are used to predict the shear tensile force with the neural network. The transparent samples are welded to black absorbent samples in overlap configuration and shear tensile tests are performed. In this work, the prediction of the shear tensile force with an accuracy of 88.1 % of the neuronal network based expert system is demonstrated.
Additive manufacturing, laser transmission welding, neural networks, expert system
During flat die rolling, two die plates pass each other and form the cylindrical semi-finished product enclosed within. Non-circular rolling examines the rolling of multiple, locally nonround geometries such as eccentrics. With the aid of statistical experimental design, a simulative parameter investigation has been carried out, main influencing variables have been recognised and process windows identified.
non-round, eccentric, flat jaw tools, preforms, intermediate forms, FEM
How can additively manufactured components be laser welded? Their layered structure makes the welding process more complicated than for conventionally produced parts. IPH and LZH are jointly researching how components can nevertheless be joined in a quality-assured manner.
Additive manufacturing, 3D printing, laser transmission welding, joining, quality
In manual solid forming, hand-guided forging tongs are used when processing forged parts. During the forging process, employees are physically stressed by high forging part weights and transmitted impacts. This physical stress leads to employee health limitations and increases absenteeism rates. Ergonomic forging tongs have been developed at IPH that lead to a relief of the forging employees.
ergonomics, forging tongs, forming technology, prevention
Factory planning can increase the productivity of manufacturing significantly, though the process is expensive when it comes to cost and time. In this paper, we propose an Unmanned Aerial Vehicle (UAV) framework that accelerates this process and decreases the costs. The framework consists of a UAV that is equipped with an IMU, a camera and a LiDAR sensor in order to navigate and explore unknown indoor environments. Thus, it is independent of GNSS and solely uses on-board sensors. The acquired data should enable a DRL agent to perform autonomous decision making, applying a reinforcement learning approach. We propose a simulation of this framework including several training and testing environments, that should be used for developing a DRL agent.
drone, UAS, deep reinforcement learning
In this paper, objective functions for the optimisation of modular conveyor systems will be introduced. Modular conveyor systems consist of conventional as well as modular conveyor hardware, which are arranged in form of matrix-like layouts. The aim of an ongoing research project is to provide small and medium-sized enterprises with a user-friendly decision support for the selection and planning of modular conveyor systems. For this purpose, the conveyor systems should be evaluated according to the objectives throughput and space requirement. Therefore, mathematical equations have been developed, which enable a fast and precise evaluation of layouts. The paper focuses mainly on the efficient calculation of the throughput. The result quality of the evaluation equations regarding the throughput was proven by a simulation of example systems.
modular conveyor, conveyor system evaluation, throughput analysis, layout optimisation, logistics
A volatile, non-transparent market environment leads to fluctuations in the load on production capacities in the manufacturing sector, which are reflected within production in the over- or underutilization of machines and persons. Small and midsized enterprises (SMEs) are expecting increasing volatility, which is accompanied by an increase in the frequency of market and economic cycles. For SMEs it is difficult to cope with these fluctuations. Capacity sharing platforms can be a solution for this challenge. Platforms are available in different forms, but not used by companies often, because of prevailing scepticism in different fields. Therefore, a methodology will be developed to provide a decision support for or against platform usage. Additionally, the platform type choice will be supported, and the changes of logistic and economic indicators will be considered. With this information companies can make a qualitative decision, and the existing inhibitions can be alleviated.
capacity sharing, decision support, supplier and consumer view, logistic and economic indicators
The results of the wear investigations will allow multidirectional processes in hot forging to be optimized in the future in a low-wear and economical manner. The determined, wear-inducing process parameters within the design guideline represent elementary basic knowledge which can be applied in a process-specific manner. In principle, the economic potential of multi-directional forging processes using of multi-directional forging processes using sliding dies depends on the application and the desired component geometries. Multi-directional forging processes forging processes offer great potential for savings and can be process design using the results obtained, they can achieve high tool life and have a positive influence on the competitive situation of companies. As a result costs for explicitly selected niche components with significantly higher with significantly increased complexity can be reduced in the future with manageable investment costs in the future. In addition to the process-specific optimization of the process parameters, in the future options for mold design adaptation with regard to local cooling or local cooling or thermal insulation of the slide-wedge wedge mechanics, in order to be able to use the systems in automated series automated series production.
Slide tools, process design, economic efficiency, solid forming
The internal supply chain in companies includes all areas from procurement to shipping. It is characterised by a heterogeneous process landscape, often accompanied by repetitive, administrative tasks. These are usually associated with a high level of manual effort and a high potential for errors. An example of this is the manual entry of delivery notes into an enterprise resource planning (ERP) system. Even incremental improvements already help SMEs enormously to cope with the heterogeneity of processes in the internal supply chain. Robotic Process Automation (RPA) is a promising approach to this. RPA offers the potential to automate administrative processes in internal supply chain that previously did not seem automatable.
Logistik, innerbetriebliche Lieferkette, robotic process automation, RPA
