Advanced Materials Research Vol. 907

Abstract: Total hip arthroplasty (THA) is a routine procedure for the treatment of advanced hip joint damage. The long-term result of the prosthesis is mainly determined by migration or aseptic loosening caused by bone remodelling. Especially the migration of the artificial hip cup as a consequence of the remodelling process is a major problem. Patient-specific hip cups can be used to counteract this. However, individual hip cups are currently only implanted for the treatment of great deformations or tumours in the hip joint due to the cost-intensive manufacturing. The aim of this project is the development and establishment of a concept for the economical production of patient-individual prosthetic hip cups out of titanium sheets. This process consists of two steps. First, undersized cups of a universal acetabulum geometry are produced. In the second step a true-to-size enlargement of the produced universal cup prothesis is carried out by means of a modified adaptive rubber-die forming process. The development of this process is accompanied by a simulationbased planning of the production process as well as by a realization of a metal forming adapted design method. For the examination of the feasibility of the concept, CT-data of canine pelvis geoemtries are used because of the large number of CT data, which were aviable for the project. Furthermore it is planned, that the first manufactured prototypes will be tested using canine cadaver. In this study the planning of the manufacturing of the standardized titanium sheet metal components is carried out. For this two methods of producing the standardized hip cup were compared. The first method is a hydraulic forming; the second is a normal pressing process with a bunch die and a binder. Pure titanium was introduced in the simulation, which shows the same mechnical properties like the in prosthetics normally used titanium alloy TiAl6V5. The results of the process simulation of both methods showed that the reducing of the blank thickness is a problem of the manufacturing of the prosthesis. Because of that an adaption of the tool geometry was executed and the influence of the increase of the forming temperature at 200 C was examined. These simulations indicated, that the hydraulic forming seems to be a convenient method to produce the prosthetic acetabulum. The first part of the metal forming adapted design method is the deduction of a universal acetabulum geometry, which has to be designed for the production of the standardized component. This deduction shall be realized by means of a superposition of 3D models of pelvis geometries. For this, two different superposition methods were compared and the Best Fit method was determined as the suitable method. By means of the Best fit method a first universal geometry was created.

Abstract: The industrial relevance of bore holes with small diameters and high length-to-diameter ratios rises with the growing requirements on parts and the tendency of components toward downsizing. Examples are components for medical and biomedical products or fuel injection in the automotive industry. An adapted process design is necessary for the production of deep holes with very small diameters, especially when the conditions at the beginning of the deep hole drilling process are unfavorable. In these applications, a hybrid process consisting of a laser pre-drilling and a single-lip deep hole drilling can shorten the process chain in machining components with non-planar surfaces, or can reduce tool wear in machining case-hardened materials. In this research, the combination of laser and single-lip drilling processes was realized and investigated for the very first time. In addition, results for the machining of workpieces with non-planar surfaces are presented.

Abstract: In this paper, current results of a research project combining ultra precision machining and optical measurement are presented. The goal is to improve the quality of specular freeform surfaces manufactured by ultra precision slow slide servo turning by running appropriate correction cycles on the basis of machine integrated measurements. These measurements are conducted using the principle of Phase Measuring Deflectometry (PMD) in order to optically acquire full-field 3D-height data. For this purpose, a special setup the so called Mini PMD that can be operated within the limited installation space of an ultra precision machine tool has been designed and implemented. Results of machine integrated measurements of a specular non-rotational symmetrical surface are presented. Furthermore, using Mini PMD and a rotationally symmetric test surface, a complete correction cycle is demonstrated without the necessity of taking the workpiece off the machine for measurement.

Abstract: A work space surveillance of a robot assistance system is presented to support people in production environments to prevent health damage, support disabled workers and which can also be used in medicine near areas. The system is based on a ToF camera that delivers the current situation of the observed scene in real time and enables detecting and tracking static and dynamic objects including humans. An automated path planning and a collision avoidance module of the employed robot are using the current information of the monitored work space to enable the utilization of the assistance system by non-experts.

Abstract: The use of microfluidic devices brings some benefits such as low reagent consumption, shorter analysis time, portability and cost reduction. The potential of this technology has constantly grown over time and lead to the development of competitive manufacture processes. The production of such microfluidic devices is usually done by molding processes which allow mass production of polymer disposables with a low cost per unit. In a prototype phase these methods are, however, expensive. To overcome the multi-step fabrication the direct milling in polymer is an alternative. In this paper micro structures are directly milled in polymethyl methacrylate (PMMA) with self-developed micro end mills and the proper CAD/CAM integration offering a fast response in manufacturing of complex structures even in the micrometer range The direct milling of structures in PMMA with micro tools-diameter 120 μm is a feasible method to produce a physical prototype. The chosen micro end mills and strategies represent a competitive process in a prototyping level by reducing time to market.

Abstract: The increasing demand of electric vehicles and thus Lithium-Ion batteries results in a multitude of challenges in production technology. The cost-effectiveness, reproducibility, performance and safety requirements of large scale batteries for automotive applications are very high. At the same time the production processes are complex and have many uncertainties, namely how single parameters influence the specific values of the battery performance. Therefore, this article focuses on the design and optimization of production processes of large scale batteries using an established FMEA approach. This method is applied to the electrode packaging process, which constitutes a crucial production step, as the anode and cathode material is assembled to create a multi-layer cell. Based on a failure mode ranking, two categories of essential failure are considered in detail. First the positioning error of the electrode foils and following this the multi-layer handling during the process. Here, an algorithm to simulate the stacking error is presented and a sensor concept to detect multi gripped layers during the handling by a gripper integrated eddy current sensor is introduced.

Abstract: The increasing electrification of the drive train will - sooner or later - lead to significant changes in the value chains for vehicle manufacturers and suppliers, while sales potentials are still uncertain. Due to the currently small number and high diversity of industrial electric motors with higher power and the complex handling of the necessary materials, the processes are based on manual labor content. For the automotive industry high volume production concepts for electric traction motors will be required in the future. Thus, the importance of automated assembly and manufacturing technologies for electric motors moves into focus. In the production of electric motors e.g. the wiring processes of the stators and the magnet assemblies for permanent-magnet synchronous rotors show potential for further process rationalization. This paper presents alternative approaches for the automation of wiring and magnet assembly processes developed at the Institute for Factory Automation and Production Systems (FAPS) at the Friedrich-Alexander-University of Erlangen-Nuremberg.

Abstract: In today's society the continuously increasing consumption of raw materials and the associated impacts on the ecosystem tend to be a frequently discussed topic. Especially automobile companies are faced to develop new driving concepts due to the emerging energy turnaround. Usually the components of the conventional drive are replaced by an electric engine including the required energy storage. Without structural changes regarding the chassis this procedure causes an increase in the vehicle ́s weight (Conversion Design). Therefore a new approach is to integrate the battery as a load-bearing member in the vehicle structure and additionally use a weight-optimized multi-material design of the body (Purpose Design). By savings of 25% of the weight of a compact-class vehicle body, a resource-saving and energy-efficient design of the entire vehicle can be achieved. Certainly the innovative multi-material construction contributes significantly to reduce the total energy consumption of the vehicle during the use phase. Based on a Lifecycle-Assessment (LCA) the environmental sustainability of the Purpose Design will be evaluated and compared to the approach of the Conversion Design. In addition to the weight savings of the multi-material body secondary weight reductions regarding the energy storage will be taken into account. The aim is to assess the ecological advantages of the lightweight solution throughout the entire product life cycle comprising the extraction of raw materials, production of the components, use of the product and end of life including the recycling of components. However, these investigations will be carried out for the modified chassis and the lightweight constructed multi-material body. Hence, the processes of the individual life cycle phases will be collected, inventorial analysis carried out and impact assessments performed. According to the LCA it will be tested, if the additional expenses in raw material extraction, production and recycling of the lightweight body justify the expected ecological advantage in the use phase. A final overall analysis will provide information on the actual efficiency and sustainability of the Purpose Design. Due to the parallel creation of the LCA data during the development process the LCA results furthermore serve to detect and monitor significant shortcomings on component and assembly level.

Abstract: Magnetic pulse production methods such as forming, joining or separating demonstrate innovative high-speed processes. Such processes can be realized using a capacitor and an appropriate tool coil for forming and welding processes. The process strain rates, which can amount to 20,000 s-1, increase the formability of metallic materials significantly. Magnesium and aluminium alloys find a wider application in the automotive industry due to their light weight potential. Through the low density of these materials, the vehicle weight can be reduced considerably. Due to the hexagonal lattice of magnesium alloys industry-relevant deformation in metal forming processes can only be achieved in hot forming processes. The high-speed forming allows a significant increase of deformability of this alloy. The use of dissimilar metals in an assembly requires the development of innovative joining methods. Apart from being used form and force closure the magnetic pulse welding and adhesive bonding material with different partners is possible. Currently at the Institute for Machine Tools and Factory Management (IWF), TU Berlin, various research topics in the field of pulsed magnetic are investigated. The magnetic pulse sheet metal forming of magnesium alloys at room temperature is investigated in a basic research project. A defined demarcation of high-speed forming with respect to the quasi-static deformation is done by means of hardness measurements in the deformation zone. For this purpose a suitable experimental setup with different matrices is constructed. The experimental results of the pulse magnetic deformation are iteratively compared with simulation results. The aim is to develop a new material model which gives a precise prediction about the high-speed process. In the field of magnetic pulse welding, both basic research and industry-related research projects conducted at the IWF. The process requires an adapted tool coil geometry that meets the requirements of the weld geometry. Different coil geometries and weld geometries and possible applications are presented by way of example, the welding quality is quantified by means of different analytical methods. The material microstructure in the weld zone, characterized by light and scanning electron microscopy shows the typical features of a shock welded joint, as also observed in explosive welding.

Abstract: The megatrend electric mobility induces a significant demand for high energy and high power secondary batteries. Currently lithium-ion technologies are the most promising solution for electrochemical energy storage in hybrid electric vehicles (HEV) and battery electric vehicles (BEV) [1; .Core factors that influence the quality, the performance and the cost of high energy lithium-ion batteries are production technologies, quality measurement techniques and quality management methods [3; . For this reason the Institute for Machine Tools and Industrial Management set up the Research Center for the Production of High-Energy Battery Cells (R-PHEB). In this research center production technologies are investigated according to industrial requirements. Research thrust areas are: first, process and assembly system design; second, quality assurance and management; and third, value chain analysis and design.The mass production of large lithium-ion cells for EV applications is an infant industry; new production technologies are often used in this field [. Hence, the influences of those processes on product properties are not known and the product quality can be evaluated only after the final production step. In order to obtain a resource efficient and economic production of lithium-ion cells, the correlations between the cell performance, the cell quality, the production processes and the assembly system design need to be revealed.This paper focuses on fundamental investigations of the process chain for the production of lithium-ion cells. It introduces a product-and a process-model, both of which specifically match the requirements in the field of battery production. The models can be used individually to describe the product structure or the process chain. Additionally they can be linked via a correlation matrix in order to visualize the dependencies between the requirement specifications of lithium-ion cells and the manufacturing processes (including process alternatives). Both models are based on a layered structure and contain information about battery cell design, battery type and production processes covering all tasks from coating the electrode coils to the start-of-operation of the cells.The product-model, the process-model and the correlation matrix will be implemented in a database, which in the future can be used for the methodical design of assembly systems as well as to investigate the correlations between process parameters and output quality. Furthermore, the database can assist when evaluating established process chains or preparing make-or-buy decisions in the context of battery cell production.