Topological design and additive manufacturing of porous metals for bone scaffolds and orthopaedic implants: A review.

The German manufacturing industry has to withstand an increasing global competition on product quality and production costs. As labor costs are high, several industries have suffered severely under the relocation of production facilities towards aspiring countries, which have managed to close the productivity and quality gap substantially. Established manufacturing companies have recognized that customers are not willing to pay large price premiums for incremental quality improvements. As a consequence, many companies from the German manufacturing industry adjust their production focusing on customized products and fast time to market. Leveraging the advantages of novel production strategies such as Agile Manufacturing and Mass Customization, manufacturing companies transform into integrated networks, in which companies unite their core competencies. Hereby, virtualization of the processand supply-chain ensures smooth inter-company operations providing real-time access to relevant product and production information for all participating entities. Boundaries of companies deteriorate, as autonomous systems exchange data, gained by embedded systems throughout the entire value chain. By including Cyber-PhysicalSystems, advanced communication between machines is tantamount to their dialogue with humans. The increasing utilization of information and communication technology allows digital engineering of products and production processes alike. Modular simulation and modeling techniques allow decentralized units to flexibly alter products and thereby enable rapid product innovation. The present article describes the developments of Industry 4.0 within the literature and reviews the associated research streams. Hereby, we analyze eight scientific journals with regards to the following research fields: Individualized production, end-to-end engineering in a virtual process chain and production networks. We employ cluster analysis to assign sub-topics into the respective research field. To assess the practical implications, we conducted face-to-face interviews with managers from the industry as well as from the consulting business using a structured interview guideline. The results reveal reasons for the adaption and refusal of Industry 4.0 practices from a managerial point of view. Our findings contribute to the upcoming research stream of Industry 4.0 and support decisionmakers to assess their need for transformation towards Industry 4.0 practices. Keywords—Industry 4.0., Mass Customization, Production networks, Virtual Process-Chain. Malte Brettel, chairholder, is with the Aachen University (RWTH), Kackertstraße 7, 52072 Aachen (e-mail: brettel@win.rwth-aachen.de). Niklas Friederichsen is with the Aachen University (RWTH), Kackertstraße 7, 52072 Aachen, (corresponding author; phone: +49/(0)241 80 99397; e-mail: friederichsen@win.rwth-aachen.de). Michael Keller and Marius Rosenberg are with the Aachen University (RWTH), Kackertstraße 7, 52072 Aachen (e-mail: keller@win.rwthaachen.de, rosenberg@win.rwth-aachen.de).

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How Virtualization, Decentralization and Network Building Change the Manufacturing Landscape: An Industry 4.0 Perspective

The past few decades have seen substantial growth in Additive Manufacturing (AM) technologies. However, this growth has mainly been process-driven. The evolution of engineering design to take advantage of the possibilities afforded by AM and to manage the constraints associated with the technology has lagged behind. This paper presents the major opportunities, constraints, and economic considerations for Design for Additive Manufacturing. It explores issues related to design and redesign for direct and indirect AM production. It also highlights key industrial applications, outlines future challenges, and identifies promising directions for research and the exploitation of AM's full potential in industry.

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Design for additive manufacturing: trends, opportunities, considerations, and constraints

3D printing of Aluminium alloys: Additive Manufacturing of Aluminium alloys using selective laser melting

Design for manufacture and assembly (DFM) has typically meant that designers should tailor their designs to eliminate manufacturing difficulties and minimize manufacturing, assembly, and logistics costs. However, the capabilities of additive manufacturing technologies provide an opportunity to rethink DFM to take advantage of the unique capabilities of these technologies. As mentioned in Chap. 16, several companies are now using AM technologies for production manufacturing. For example, Siemens, Phonak, Widex, and the other hearing aid manufacturers use selective laser sintering and stereolithography machines to produce hearing aid shells; Align Technology uses stereolithography to fabricate molds for producing clear dental braces (“aligners”); and Boeing and its suppliers use polymer powder bed fusion (PBF) to produce ducts and similar parts for F-17 fighter jets. For hearing aids and dental aligners, AM machines enable manufacturing of tens to hundreds of thousands of parts, where each part is uniquely customized based upon person-specific geometric data. In the case of aircraft components, AM technology enables low-volume manufacturing, easy integration of design changes and, at least as importantly, piece part reductions to greatly simplify product assembly.

Design for Additive Manufacturing

This paper provides an overview on the main additive manufacturing/3D printing technologies suitable for many satellite applications and, in particular, radio-frequency components. In fact, nowadays they have become capable of producing complex net-shaped or nearly net-shaped parts in materials that can be directly used as functional parts, including polymers, metals, ceramics, and composites. These technologies represent the solution for low-volume, high-value, and highly complex parts and products.

Overview on Additive Manufacturing Technologies

Purpose – The purpose of this paper is to highlight how rapid manufacturing (RM) of plastic parts combined with part redesign could have positive repercussion on cost saving.Design/methodology/approach – Comparison between two different technologies for plastic part production, the traditional injection molding (IM) and the emergent RM, is done with consideration of both the geometric possibilities of RM and the economic aspect. From an extended literature review, the redesign guidelines and the cost model are identified and then applied to a component selected for its shape complexity. It is an assembly that was redesigned for RM purpose, in order to take advantage of additive manufacturing potentialities. The geometric and economic differences between IM and RM are discussed.Findings – This research evidences that currently in Western Europe RM combined with redesign can be economically convenient and competitive to IM for medium volume production of plastic parts. Consequently, this is a great opportun...

Redesign and cost estimation of rapid manufactured plastic parts

Inconel 625 (IN625) is a Ni superalloy ideal for the aeronautic and aerospace industries because of its superior mechanical and corrosion resistance properties. However, the production of components with complex geometries by traditional processes is very expensive, so additive manufacturing (AM) technologies can be applied to reduce the costs. In this work, IN625 alloy is processed by two different AM processes: selective laser melting (SLM) and laser metal deposition (LMD). First, the different powders are characterized, and then a parameter optimization is performed to obtain the highest possible density (over 99.8%) and hardness, showing very fine microstructures. The LMD process allows the highest build-up rate, but results in less dimensional accuracy and a lower hardness than the SLM process.

Characterization and Comparison of Inconel 625 Processed by Selective Laser Melting and Laser Metal Deposition

Additive Manufacturing (AM) and 3D printing are drivers for material savings in manufacturing. Owing to the continuous diffusion of 3D printing driven by low-cost entry-level material extrusion printers, sustainability of a so popular AM technology is of paramount importance. Therefore, recycling 3D printed wastes and 3D parts again at the end of their life is an important issue to be addressed. Research efforts are directed towards the improvement of the biodegradability of 3D printing filaments and the replacement of oil based feedstock with bio-based compostable plastics. The aim of this work is to describe the state of the art about development and use of recycled or biodegradable filaments in 3D printing. Beyond a critical review of the literature, open issues and research opportunities are presented.

About the Use of Recycled or Biodegradable Filaments for Sustainability of 3D Printing

https://iris.polito.it/bitstream/11583/2633926/1/CMS%202015%20-%20Benchmarking%20of%20FDM%20machines.pdf

Paolo Minetola

Papers

Overview on Additive Manufacturing Technologies

Redesign and cost estimation of rapid manufactured plastic parts

Characterization and Comparison of Inconel 625 Processed by Selective Laser Melting and Laser Metal Deposition

About the Use of Recycled or Biodegradable Filaments for Sustainability of 3D Printing

Benchmarking of FDM Machines through Part Quality Using IT Grades