Research on Layer Manufacturing Techniques at Fraunhofer

Within the German Fraunhofer-Gesellschaft, the Fraunhofer Alliance Rapid Prototyping unites the competences of 12 institutes in the field of solid freeform fabrication. Covered competences are virtual and computer-aided product planning methods and techniques, the development and integration of materials and processes for different industrial sectors. This paper presents actual research results on layer manufacturing within the Fraunhofer- Gesellschaft based on examples from Fraunhofer ILT »Laser Melting - Direct manufacturing of metal parts with unique properties«, Fraunhofer IFAM »ecoMold - A novel concept to produce molds for plastic injection molding and pressure die casting« and Fraunhofer IPT »Quick manufacture, repair and modification of steel molds using Controlled Metal Build Up (CMB)«.Mechanical Engineerin

Continuous maintenance and the future – Foundations and technological challenges

High value and long life products require continuous maintenance throughout their life cycle to achieve required performance with optimum through-life cost. This paper presents foundations and technologies required to offer the maintenance service. Component and system level degradation science, assessment and modelling along with life cycle ‘big data’ analytics are the two most important knowledge and skill base required for the continuous maintenance. Advanced computing and visualisation technologies will improve efficiency of the maintenance and reduce through-life cost of the product. Future of continuous maintenance within the Industry 4.0 context also identifies the role of IoT, standards and cyber security

Revolutionary additive manufacturing : an overview

Consumer demands are moving away from standardized to customized products, as such, the evolution of alternative manufacturing techniques has become imperative. Additive manufacturing (AM) is a process of building components layer by layer as against the traditional methods which are subtractive in nature. Though AM offers lots of advantages over traditional manufacturing techniques, its wide application is still however in the infancy phase. Despite all the benefits derived from AM technology, there are still a lot of unresolved issues with the technology that has hindered its performance thereby limiting its application to high tolerant jobs. This paper takes a look at some important AM technologies, some problems currently facing AM technology at large and proposes some solutions to these problems. A major known drawback in AM is poor dimensional accuracy and poor surface finish, only the layer height and melt pool temperature are controlled to solve this problem in the literature. The stair-stepping effect in adaptive manufacturing is rooted in a natural phenomenon of surface tension which is the cause of the poor surface finish and in combination with other factors is responsible for the poor dimensional accuracy. An adaptive controller is proposed for removing stair-stepping effect to improve the dimension accuracy, the surface finish and the mechanical properties of the components. Successful implementation of these proposed controllers will greatly improve the performance of AM technologies and also aid its wide application for end use products. Further research work is also suggested to improve the overall AM performance

Symmetry and its application in metal additive manufacturing (MAM)

Additive manufacturing (AM) is proving to be a promising new and economical technique for the manufacture of metal parts. This technique basically consists of depositing material in a more or less precise way until a solid is built. This stage of material deposition allows the acquisition of a part with a quasi-final geometry (considered a Near Net Shape process) with a very high raw material utilization rate. There is a wide variety of different manufacturing techniques for the production of components in metallic materials. Although significant research work has been carried out in recent years, resulting in the wide dissemination of results and presentation of reviews on the subject, this paper seeks to cover the applications of symmetry, and its techniques and principles, to the additive manufacturing of metals.The authors are grateful to the Basque Government for funding the EDISON project, ELKARTEK 2022 (KK-2022/00070)

Survey on Additive Manufacturing, Cloud 3D Printing and Services

Cloud Manufacturing (CM) is the concept of using manufacturing resources in a service oriented way over the Internet. Recent developments in Additive Manufacturing (AM) are making it possible to utilise resources ad-hoc as replacement for traditional manufacturing resources in case of spontaneous problems in the established manufacturing processes. In order to be of use in these scenarios the AM resources must adhere to a strict principle of transparency and service composition in adherence to the Cloud Computing (CC) paradigm. With this review we provide an overview over CM, AM and relevant domains as well as present the historical development of scientific research in these fields, starting from 2002. Part of this work is also a meta-review on the domain to further detail its development and structure

Laser Metal Deposition enhancement by holistic simulation of powder mass flow and deposition into the melt pool

El contenido de los capítulos 3, 4 y 5 está sujeto a confidencialidad. 251 p.En el presente trabajo de investigación se ha desarrollado una metodología para la mejora del proceso de aporte por láser mediante la modelización del mismo. El problema se ha abordado en diferentes pasos. Primero de todo, se ha desarrollado un cabezal de aporte que cumple con todos los requerimientos del proceso mediante un software comercial de CFD. Posteriormente, se ha fabricado y validado el mismo. Además, con el objetivo de mejorar la eficiencia de la boquilla e incrementar la estabilidad del proceso, se ha desarrollado un sistema novedoso de regulación del caudal del polvo. El cabezal de aporte ha sido empleado satisfactoriamente para la reparación y fabricación de diversas piezas. En lo que respecta a la modelización, se ha desarrollado un modelo que considera los fenómenos fluido-dinámicos que se producen dentro del baño fundido generado por un haz láser. Una vez se ha validado el modelo, se ha empleado para evaluar la importancia de considerar u omitir el movimiento del material fundido. Los resultados obtenidos indican que la influencia del movimiento del material fundido es mínima en el proceso de aporte por láser y pueden ser omitidos sin que ello suponga una pérdida de precisión. Basándose en esta última afirmación, se ha desarrollado un modelo tridimensional que simula el proceso de aporte por láser al completo. Este modelo calcula la transferencia de calor por conducción dentro de la pieza y la geometría del material aportado. Además, en función de los ciclos de calentamiento y enfriamiento que sufre el material, es capaz de predecir las propiedades mecánicas resultantes, tales como dureza, microestructura o la formación de poros

Laser Metal Deposition enhancement by holistic simulation of powder mass flow and deposition into the melt pool

El contenido de los capítulos 3, 4 y 5 está sujeto a confidencialidad. 251 p.En el presente trabajo de investigación se ha desarrollado una metodología para la mejora del proceso de aporte por láser mediante la modelización del mismo. El problema se ha abordado en diferentes pasos. Primero de todo, se ha desarrollado un cabezal de aporte que cumple con todos los requerimientos del proceso mediante un software comercial de CFD. Posteriormente, se ha fabricado y validado el mismo. Además, con el objetivo de mejorar la eficiencia de la boquilla e incrementar la estabilidad del proceso, se ha desarrollado un sistema novedoso de regulación del caudal del polvo. El cabezal de aporte ha sido empleado satisfactoriamente para la reparación y fabricación de diversas piezas. En lo que respecta a la modelización, se ha desarrollado un modelo que considera los fenómenos fluido-dinámicos que se producen dentro del baño fundido generado por un haz láser. Una vez se ha validado el modelo, se ha empleado para evaluar la importancia de considerar u omitir el movimiento del material fundido. Los resultados obtenidos indican que la influencia del movimiento del material fundido es mínima en el proceso de aporte por láser y pueden ser omitidos sin que ello suponga una pérdida de precisión. Basándose en esta última afirmación, se ha desarrollado un modelo tridimensional que simula el proceso de aporte por láser al completo. Este modelo calcula la transferencia de calor por conducción dentro de la pieza y la geometría del material aportado. Además, en función de los ciclos de calentamiento y enfriamiento que sufre el material, es capaz de predecir las propiedades mecánicas resultantes, tales como dureza, microestructura o la formación de poros

A Review of Automotive Spare-Part Reconstruction Based on Additive Manufacturing

In the Industry 4.0 scenario, additive manufacturing (AM) technologies play a fundamental role in the automotive field, even in more traditional sectors such as the restoration of vintage cars. Car manufacturers and restorers benefit from a digital production workflow to reproduce spare parts that are no longer available on the market, starting with original components, even if they are damaged. This review focuses on this market niche that, due to its growing importance in terms of applications and related industries, can be a significant demonstrator of future trends in the automotive supply chain. Through selected case studies and industrial applications, this study analyses the implications of AM from multiple perspectives. Firstly, various types of AM processes are used, although some are predominant due to their cost-effectiveness and, therefore, their better accessibility and wide diffusion. In some applications, AM is used as an intermediate process to develop production equipment (so-called rapid tooling), with further implications in the digitalisation of conventional primary technologies and the entire production process. Secondly, the additive process allows for on-demand, one-off, or small-batch production. Finally, the ever-growing variety of spare parts introduces new problems and challenges, generating constant opportunities to improve the finish and performance of parts, as well as the types of processes and materials, sometimes directly involving AM solution providers