Holger Voswinckel

Direct photonic production: towards high speed additive manufacturing of individualized goods

World market competition currently boosts trends like mass customization and open innovation which result in a demand for highly individualized products at costs matching or beating those of mass production. This work focus on the resolution of the production related dilemma between scale and scope, e.g. either the low-cost production of high quantities or the high-end and thus cost-intensive low-volume production of individualized goods. One of the areas of greatest potential for the resolution of this dilemma are rapid manufacturing (RM) technologies due to their almost infinite geometrical variability and freedom of design without the need for part-specific tooling. Selective Laser Melting (SLM) is one of the RM technologies that additionally provides series identical mechanical properties without the need for downstream sintering processes, etc. However, the state-of-the-art process and cost efficiency is not yet suited for series production. In order to improve this efficiency and enable SLM to enter series production it is indispensable to increase the build rate significantly by means of increased laser power and larger beam diameters. To exploit this potential, a new generation production machine including a kW laser and an optical multi-beam system is developed and experimental results and real life components are shown.

Process Limits of Stretch and Shrink Flanging by Incremental Sheet Metal Forming

ncremental Sheet Forming (ISF) is a manufacturing technology for individualized and small batch production. Among the opportunities this technology provides there is the possibility of a short ramp up time and to cover the whole production chain of sheet metal parts by one machine setup. Since recent works showed that manufacturing of industrial parts is feasible, finishing operations such as flanging and trimming gain importance. This paper shows first works on the technological capabilities of using ISF for stretch and shrink flanging. Due to the localized forming zone the absence of surrounding clamping devices for ISF results in differing material flow behaviour. The influences of tool path characteristics, flange length as well as radii are analysed to set up a process window.

Geometric complexity analysis in an integrative technology evaluation model (ITEM) for selective laser melting (SLM)

Selective laser melting (SLM) is becoming an economically viable choice for manufacturing complex serial parts. This paper focuses on a geometric complexity analysis as part of the integrative technology evaluation model (ITEM) presented here. In contrast to conventional evaluation methodologies, the ITEM considers interactions between product and process innovations generated by SLM. The evaluation of manufacturing processes that compete with SLM is the main goal of ITEM. The paper includes a complexity analysis of a test part from Festo AG. The paper closes with a discussion of how the expanded design freedom of SLM can be used to improve company operations, and how the complexity analysis presented here can be seen as a starting point for feature-based complexity analysis.

Design for Manufacture Based on an Integrated Product Process Design Model

This paper details an integrated product process design model that represents process capabilities by a set of key indicators and allows for the design of products taking into account constraints set out by the process. The model is applied to Incremental sheet forming (ISF) processes and their variants. ISF processes have been developed over the past 20 years and have reached a state of development now allowing for a transition from scientific research to broader industrial application. ISF with its low part specific tooling represents a technology suitable for individualized production down to one-piece-flow. Hence, it might satisfy the growing demand for individualized products in the field of sheet metal production. However, an industrial use of ISF requires that general design rules are provided to designers to enable designs that are compatible with the capabilities of ISF. Today’s product design typically is more suitable for stamping operations than for ISF which makes the fabrication of parts by ISF difficult and increases lead time and costs. Also, different variations of ISF processes exist that are based on different machines (industrial robots, CNC machines,…) and are characterized by different capabilities, e.g. in terms of accuracy. The objective of this work is the development of an integrated product process design model and its application to ISF. The capabilities of currently available ISF processes are determined and compared to the requirements of selected products from the automotive and aero-space industry.

Integrative Technology Evaluation Model (ITEM) for Selective Laser Melting (SLM)

This paper focuses on the evaluation of manufacturing processes that are competing with Selective Laser Melting (SLM). In 3D-part production of serial parts SLM is starting to be an economic choice for manufacturing. An integrated technology evaluation model (ITEM) is presented that helps decision makers to determine the potential of SLM while comparing with conventional manufacturing technologies. In contrast to conventional evaluation methodologies the ITEM considers interactions between product and process innovations generated by SLM. The paper closes with a technical and economical evaluation of a test part from Festo AG to validate two important parts of the ITEM.

Multi-technology Platforms (MTPs)

The growing demand for individualized commodities requires new solutions for a highly flexible yet cost-efficient production. Hence, the research results described in this chapter address the question of how different manufacturing technologies could be combined and employed efficiently in industrial practice. Reaching across the whole field of Multi-Technology Platforms (MTPs) a generalized design methodology was examined. The resulting template-based procedure, combining function structure and technology chains, is introduced in the first section. Consecutively, the next section advances this approach by illustrating the incorporation of metrology into machine tools and MTPs. For technological validation, all newly-developed scientific approaches were successfully integrated into four demonstrator test beds located at the RWTH Aachen University: a Multi-Technology Machining Center, a Hybrid Sheet Metal Processing Center, a Conductive Friction Stir Welding Center and a laser-enhanced hybrid lathe. The economic efficiency of manufacturing technology integration is reviewed before a profitability assessment based on the aforementioned demonstrator test beds is performed. The chapter concludes with an outlook on future research topics.