The potential of additive manufacturing in the smart factory industrial 4.0: A review

Additive manufacturing (AM) or three-dimensional (3D) printing has introduced a novel production method in design, manufacturing, and distribution to end-users. This technology has provided great freedom in design for creating complex components, highly customizable products, and efficient waste minimization. The last industrial revolution, namely industry 4.0, employs the integration of smart manufacturing systems and developed information technologies. Accordingly, AM plays a principal role in industry 4.0 thanks to numerous benefits, such as time and material saving, rapid prototyping, high efficiency, and decentralized production methods. This review paper is to organize a comprehensive study on AM technology and present the latest achievements and industrial applications. Besides that, this paper investigates the sustainability dimensions of the AM process and the added values in economic, social, and environment sections. Finally, the paper concludes by pointing out the future trend of AM in technology, applications, and materials aspects that have the potential to come up with new ideas for the future of AM explorations

Error Detection in Laser Beam Melting Systems by High Resolution Imaging

Laser Beam Melting as a member of Additive Manufacturing processes allows the fabrication of three-dimensional metallic parts with almost unlimited geometrical complexity and very good mechanical properties. However, its potential in areas of application such as aerospace or medicine has not yet been exploited due to the lack of process stability and quality management. For that reason samples with pre-defined process irregularities are built and the resulting errors are detected using high-resolution imaging. This paper presents an overview of typical process errors and proposes a catalog of measures to reduce process breakdowns. Based on this systematical summary a future contribution to quality assurance and process documentation is aspired.Mechanical Engineerin

Investigation of the effects of fabrication tolerances in microwave thick-film circuits

This project dealt with the design and fabrication of bandpass filter centered at 16 GHz using modem thick-film technology. The rapid development of the commercial microwave circuits requires a low cost, cheaper technology to replace the old, more expensive thin-film technology. Therefore, thick-film technology is the best alternative. The effects of fabrication tolerances in the physical dimensions of various parameters were being investigated as well. The analysis of the result can then be applied to determine the trade off between perfOlmance and tolerances. It is therefore extremely important to control the vmiations of parameters in microstlip with fablication tolerances to achieve the desired perfonnance

Latest Developments in Industrial Hybrid Machine Tools that Combine Additive and Subtractive Operations

Hybrid machine tools combining additive and subtractive processes have arisen as a solution to increasing manufacture requirements, boosting the potentials of both technologies, while compensating and minimizing their limitations. Nevertheless, the idea of hybrid machines is relatively new and there is a notable lack of knowledge about the implications arisen from their in-practice use. Therefore, the main goal of the present paper is to fill the existing gap, giving an insight into the current advancements and pending tasks of hybrid machines both from an academic and industrial perspective. To that end, the technical-economical potentials and challenges emerging from their use are identified and critically discussed. In addition, the current situation and future perspectives of hybrid machines from the point of view of process planning, monitoring, and inspection are analyzed. On the one hand, it is found that hybrid machines enable a more efficient use of the resources available, as well as the production of previously unattainable complex parts. On the other hand, it is concluded that there are still some technological challenges derived from the interaction of additive and subtractive processes to be overcome (e.g., process planning, decision planning, use of cutting fluids, and need for a post-processing) before a full implantation of hybrid machines is fulfilledSpecial thanks are addressed to the Industry and Competitiveness Spanish Ministry for the support on the DPI2016-79889-R INTEGRADDI project and to the PARADDISE project H2020-IND-CE-2016-17/H2020-FOF-2016 of the European Union's Horizon 2020 research and innovation program

Thermophysical Phenomena in Metal Additive Manufacturing by Selective Laser Melting: Fundamentals, Modeling, Simulation and Experimentation

Among the many additive manufacturing (AM) processes for metallic materials, selective laser melting (SLM) is arguably the most versatile in terms of its potential to realize complex geometries along with tailored microstructure. However, the complexity of the SLM process, and the need for predictive relation of powder and process parameters to the part properties, demands further development of computational and experimental methods. This review addresses the fundamental physical phenomena of SLM, with a special emphasis on the associated thermal behavior. Simulation and experimental methods are discussed according to three primary categories. First, macroscopic approaches aim to answer questions at the component level and consider for example the determination of residual stresses or dimensional distortion effects prevalent in SLM. Second, mesoscopic approaches focus on the detection of defects such as excessive surface roughness, residual porosity or inclusions that occur at the mesoscopic length scale of individual powder particles. Third, microscopic approaches investigate the metallurgical microstructure evolution resulting from the high temperature gradients and extreme heating and cooling rates induced by the SLM process. Consideration of physical phenomena on all of these three length scales is mandatory to establish the understanding needed to realize high part quality in many applications, and to fully exploit the potential of SLM and related metal AM processes

Beam-Induced Damage Mechanisms and their Calculation

The rapid interaction of highly energetic particle beams with matter induces dynamic responses in the impacted component. If the beam pulse is sufficiently intense, extreme conditions can be reached, such as very high pressures, changes of material density, phase transitions, intense stress waves, material fragmentation and explosions. Even at lower intensities and longer time-scales, significant effects may be induced, such as vibrations, large oscillations, and permanent deformation of the impacted components. These lectures provide an introduction to the mechanisms that govern the thermomechanical phenomena induced by the interaction between particle beams and solids and to the analytical and numerical methods that are available for assessing the response of impacted components. An overview of the design principles of such devices is also provided, along with descriptions of material selection guidelines and the experimental tests that are required to validate materials and components exposed to interactions with energetic particle beams.Comment: 69 pages, contribution to the 2014 Joint International Accelerator School: Beam Loss and Accelerator Protection, Newport Beach, CA, USA , 5-14 Nov 201

Improvement to the surface finish of additive laser manufactured parts made by selective laser melting

The Selective Laser Melting (SLM) process has been used since the end of last decade for different applications in the industrial sector. The priority of the technique is to produce fully dense and functional metallic parts of very complex design, but it is limited by a few issues such as quality of surface finish and porosity. The current study focuses on improving the surface finish of parts built on an SLM machine through two different approaches of post processing technique, laser re-melting followed by electropolishing. In this investigation Renishaw’s SLM 125 was employed to produce 3Dimensional (3D) parts by using stainless steel 316L material with powder particle size ranges from 15 to 45 microns. Samples with different inclinations were constructed in order to generate samples with different surface roughness; the parts were measured and inspected for surface finish by measuring Ra. The initial surface roughness ranges from 10 to 20μm Ra. Due to the poor surface quality, laser re-melting was implemented as a first stage in order to eliminate the initial surface roughness. Laser re-melting as a post-processing technique was employed for re-melting procedure employing the RECLAIM machine at Manufacturing Technology Centre (MTC) Coventry. Different setups of process were analysed to optimize the parameters for re-melting. The results proved that the best results are conducted with laser energy density ranges between 2160 to 2700 J/cm2 to give exceptional results of surface roughness of about 1.4 μm±15% Ra. In such case it’s possible to say that laser re-melting has the capacity to improve surface finish by about 80% compared to the initial surface roughness created by SLM. In the second stage, improvement was carried out by implementing green process to reduce the waste, pollution and high toxicity using a suitable room temperature ionic liquid (RTLs) as a solution in order to eliminate the secondary surface roughness that comes after re-melting. Physical properties such as shininess and reflectivity were significantly improved, due to the capacity of the process to improve the surface roughness and remove the oxide film created during re-melting. The method proved that the best results were obtained when the specimens were anodically kept at current densities associated with potential ranges between (4 to 5.5 volt), maintained at (40 C°) to give roughness (Ra) less than 0, 5μm. These levels of voltage can be facilitated to operate and avoid any passivation of material dissolving, which can lead to pitting of the surface.Libyan Governmen

Multi-Scale Multi-Physics Modeling of Laser Powder Bed Fusion Additive Manufacturing

Laser Powder Bed Fusion (LPBF) is a fast-developing metal additive manufacturing process offering unique capabilities including geometric freedom, flexibility, and part customization. The process induces complicated thermal histories with high temperature gradients and cooling rates, leading to rapid solidification microstructures with anisotropic properties as different from those produced conventionally. In addition, the LPBF parts exhibit to a large extent of in-sample and sample-to-sample variabilities in the microstructure and consequently part performance. The high variability in the microstructure and properties is considered the major obstacle against the widespread adoption of LPBF as a viable manufacturing technique. Therefore, a more in depth understanding and control of the solidification microstructure is needed to achieve the LPBF fabricated parts with desired properties. Since the solidification microstructure is highly influenced by the thermal input, it is essential to have an accreditable thermal model first. Therefore, a portion of this dissertation was devoted to developing an accurate thermal model through various methods including code-to-code verification and experimental validation. The materials used in this portion include Ti-6Al-4V, NiTi-SMA (Shape Memory Alloy). Next, a multi-scale multi-physics modeling framework which couples a finite element (FE) thermal model to a non-equilibrium phase field (PF) model was developed to investigate the rapid solidification microstructure during LPBF. The framework was utilized to predict the spatial variation in the morphology, size and micro-segregation in the single-track deposition of binary NiNb alloy during LPBF and a very good agreement with the experimental measurements was achieved