Cellular materials are spread all across the world. They can be found in nature, e.g. in bone and wood, as well as in engineering applications such as honeycomb sheets and aluminum foams to name but a few. Cellular materials have some unique properties which allow new and innovative applications beyond the scope of solid engineering materials. Especially their low density and therefore their outstanding stiffness-to-weight-ratio is of greatest importance in most applications. Functions of cellular materials could be lightweight structures of high stiffness, damping and absorption of mechanical energy, vibration control, acoustic absorption, heat exchange, filtering and numerous other tasks. Generally, a combination of these tasks in one part exhibits an optimized and therefore innovative overall performance. One recent development in production technologies is the field of Laser Freeform Fabrication (LFF) processes where parts are manufactured by application of thin layers of powder or sometimes liquid material. A laser beam melts and solidifies the material along contour lines and hatch areas according to slices of a corresponding 3D-CAD model. Among these processes the Selective Laser Melting (SLM) technology was advanced based upon the work in this thesis to allow the manufacture of periodic, open-cell lattice structures from engineering materials such as stainless steel, titanium, etc. In contrast to other cellular materials these lattice structures can be of well-defined, nearly arbitrary shape. Due to the layerwise fabrication the SLM process is also capable of creating lattice cores surrounded by solid shells allowing new degrees of geometric freedom in engineering design that was never experienced before in conventional machining. This allows the development of interesting new applications such as medical implants where the main issues are the improvement of osseointegration and realization of physioelastic material properties for an optimized bond between the implant and surrounding tissue. Lattice structures obtained from the SLM process can meet these requirements. This thesis contributes to the understanding of the mechanical properties of the new material class of SLM lattice structures. Their future incorporation in engineering designs requires a profound knowledge of failure mechanisms and operational limits. Therefore, a comprehensive summary is given on the state-of-the-art of cellular materials followed by a dedicated analysis on Laser Freeform Fabrication and an in-depth validation of the Selective Laser Melting capabilities. Readers with advanced knowledge on cellular materials or Laser Freeform Fabrication may skip sections 2 or 3, respectively. Next, all process constraints and boundary conditions for the manufacture of SLM lattice structures are elaborated. Then a bilateral approach was chosen to derive scaling laws and optimize the SLM lattice structures for given tasks. Firstly, a theoretical analysis comprises the examination of structural hypotheses for isotropic cellular materials before a generalized theory is developed for anisotropic SLM lattice structures. Different cubic, polyhedral and rhombic cell types are evaluated towards their producibility. Some of these cell types are preselected and are subject to numerical analysis where their mechanical properties are derived on the basis of the space framework theory. Secondly, an extensive experimental evaluation of test specimens is given. This includes examinations of the properties of SLM solids, the producibility of SLM lattice structures in terms of dimensions and testing of their mechanical properties such as strength and elasticity in compression, tension and shear load. The test procedures are divided in three stages. The first stage comprises the examination of the specific strength in dependence of the cell type to narrow down few optimum cell types for different applications. In the second and third stage these cell types are investigated towards their elasticity and strength in dependence of the cell size. Finally, this thesis concludes with scaling laws provided in accordance with the theoretical and experimental results. Opposed to simple power laws used for cellular materials these newly developed scaling laws consider leaps in properties at higher, so-called critical relative densities which can be obtained from SLM due to its high degree of design freedom. At the critical relative density SLM lattice structures cease being frameworks and become rather solids with pores. For future applications these scaling laws can be applied by design engineers to match particular requirements that can only be fulfilled by Laser Freeform Fabrication and its degrees of freedom in design. For the sake of completeness some sample applications in the field of medical implants are given in this thesis, which involve these scaling laws.

Collection of 120 peer-reviewed papers that were presented at the 3rd International Conference on Advanced Research in Virtual and Rapid Prototyping, held in Leiria, Portugal in September 2007. Essential reading for all those working on V&RP, focused on inducing increased collaboration between industry and academia. In addition to key

Laser Additive Manufacturing: Materials, Design, Technologies, and Applications provides the latest information on this highly efficient method of layer-based manufacturing using metals, plastics, or composite materials. The technology is particularly suitable for the production of complex components with high precision for a range of industries, including aerospace, automotive, and medical engineering. This book provides a comprehensive review of the technology and its range of applications. Part One looks at materials suitable for laser AM processes, with Part Two discussing design strategies for AM. Parts Three and Four review the most widely-used AM technique, powder bed fusion (PBF) and discuss other AM techniques, such as directed energy deposition, sheet lamination, jetting techniques, extrusion techniques, and vat photopolymerization. The final section explores the range of applications of laser AM. - Provides a comprehensive one-volume overview of advances in laser additive manufacturing - Presents detailed coverage of the latest techniques used for laser additive manufacturing - Reviews both established and emerging areas of application

This contributed volume contains the research results of the Cluster of Excellence “Integrative Production Technology for High-Wage Countries”, funded by the German Research Society (DFG). The approach to the topic is genuinely interdisciplinary, covering insights from fields such as engineering, material sciences, economics and social sciences. The book contains coherent deterministic models for integrative product creation chains as well as harmonized cybernetic models of production systems. The content is structured into five sections: Integrative Production Technology, Individualized Production, Virtual Production Systems, Integrated Technologies, Self-Optimizing Production Systems and Collaboration Productivity.The target audience primarily comprises research experts and practitioners in the field of production engineering, but the book may also be beneficial for graduate students.

This work reviews the current state of the art in metallic microlattice structures, manufactured using the additive manufacturing processes of selective laser melting, electron beam melting, binder jetting and photopolymer wave guides. The emphasis is on structural performance (stiffness, strength and collapse). The field of additively manufactured metallic microlattice structures is fast changing and wide ranging, and is being driven by developments in manufacturing processes. This book takes a number of specific structural applications, viz. sandwich beams and panels, and energy absorbers, and a number of conventional metallic materials, and discusses the use of additive manufactured metallic microlattice structures to improve and enhance these structural performances. Structural performances considered includes such non linear effects as plasticity, material rupture, elastic and plastic instabilities, and impact loading. The specific discussions are put into the context of wider issues, such as the effects of realisation processes, the effects of structural scale, use of sophisticated analysis and synthesis methodologies, and the application of existing (conventional) structural theories. In this way, the specific discussions are put into the context of the emerging general fields of Architectured (Architected) Materials and Mechanical Metamaterials.

This edited volume contains the selected papers presented at the scientific board meeting of the German Cluster of Excellence on “Integrative Production Technology for High-Wage Countries”, held in November 2014. The topical structure of the book is clustered in six sessions: Integrative Production Technology, Individualised Production, Virtual Production Systems, Integrated Technologies, Self-Optimising Production Systems and Human Factors in Production Technology. The Aachen perspective on a holistic theory of production is complemented by conference papers from external leading researchers in the fields of production, materials science and bordering disciplines. The target audience primarily comprises research experts and practitioners in the field but the book may also be beneficial for graduate students.

This book covers the application technology of lasers, focusing more on the vast range of processes than on individual applications, in order to motivate and enable future innovations. The physical basics are presented in the first half of the book. The following examination of application categories and their processes is documented by experts from their practical points of view but always refers back to the underlying physical principles. In this way, readers are free to choose their own individual level of depth in understanding this globally relevant field of innovation. This new edition of Tailored Light 2: Laser Applications birings the book up to date with the latest applications of laster technology.