3,424 research outputs found

    Advancements in extrusion and drawing: a review of the contributes by the ESAFORM community

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    The present review paper would celebrate the 25 years anniversary of the ESAFORM association by summarizing the studies performed by the delegates of the ESAFORM conference series within mini-symposium “Extrusion and Drawing” and of the papers published in the International Journal of Material Forming in the same fields. The 160 analyzed papers have been divided in four main categories corresponding to the paper main chapters (Hot Metal Extrusion, Cold Metal Extrusion, Polymer Extrusion and Drawing) then further divided in sub-chapters in order to group them in more specific research subjects. The aim of this review paper is then to provide to the reader a complete overview of the investigated topics and of the research trends over the years within the ESAFORM associate researchers

    Fast algorithms for material specific process chain design and analysis in metal forming - final report DFG Priority Programme SPP 1204

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    The book summarises the results of the DFG-funded coordinated priority programme \"Fast Algorithms for Material Specific Process Chain Design and Analysis in Metal Forming\". In the first part it includes articles which provide a general introduction and overview on the field of process modeling in metal forming. The second part collates the reports from all projects included in the priority programme

    FEA Modelling of Weld-deposition based Additive Manufacturing for the Residual Stress Prediction

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    Research in the development of additive manufacturing process employing direct metal deposition for the fabrication of fully functional parts and tooling has generated significant interest in the recent years. Three-dimensional welding is being investigated as an additive manufacturing technique for the production of real metallic parts using gas metal arc welding (GMAW) principles. The temperature field distribution during weld based rapid prototyping induces complex thermal stress evolutions and plays a big role in residual stress distributions. The present work is to investigate the temperature field and thermal stress distributions in the multi-pass single-layer weld-deposition based additive manufacturing using twin wire welding. A three-dimensional finite element model with the temperature-dependent material properties and moving heat source is modelled for the same. A double ellipsoidal heat source model is applied to calculate the twin wire welding‟s temperature field is used. The filler metal deposition is taken into account by implementing the birth-and-death functionality for the finite elements. The temperature distribution pattern and magnitude is subsequently obtained. This result is then used for estimation of residual stress and distortion due to the twin wire welding

    Recoater-induced distortions and build failures in selective laser melting of thin-walled Ti6Al4V parts

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    Additively manufactured thin-walled structures through selective laser melting (SLM) are of great interest in achieving carbon-neutral industrial manufacturing. However, residual stresses and warpages as well as recoater crashes often occur in SLM, leading to the build failure of parts, especially for large-scale and lightweight geometries. The challenge in this work consists of investigating how the recoater affects the warpage and (sometimes) causes the failure of different thin-walled Ti6Al4V parts (wall thickness of 1.0 mm). All these parts are printed on the same platform using a commercial SLM machine. After the loose powder removal and before the cutting operation, a 3D-scanner is used to obtain the actual warpage of each component. Next, an in-house coupled thermo-mechanical finite element model suitable for the numerical simulation of the SLM process is enhanced to consider the recoater effects. This numerical framework is calibrated to predict the thin-walled warpage as measured by the 3D-scanner. The combination of numerical predictions with experimental observations facilitates a comprehensive understanding of the mechanical behavior of different thin-walled components as well as the failure mechanism due to the recoater. The findings show that the use of a higher laser energy input causes larger residual stresses and warpage responsible for the recoater crashes. Finally, potential solutions to mitigate the warpage and the recoater crashes in the SLM of lightweight structures are assessed using the validated model.This research was funded by the Spanish Ministry of Economy and Competitiveness, through the Severo Ochoa Programme for Centers of Excellence in R&D (CEX2018-000797-S). This work has been supported by the Ministry of Science, Innovation and Universities (MCIU), Spain via the PriMuS project (Printing pattern based and MultiScale enhanced performance analysis of advanced Additive Manufacturing components, No. PID2020-115575RB-I00) and by the Light3D project (No. 001-P-001646) as part of the BASE3D network by ACCIÓ (Generalitat de Catalunya). The support from the China Scholarship Council (No. 201906290011) is also gratefully acknowledged.Peer ReviewedPostprint (published version

    Review on thermal, thermo-mechanical and thermal stress distribution during friction stir welding

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    Abstract: Thermal has significant effects on the metal structure during welding process; it plays vital roles in rearranging molecular structure of the metal being welded. It is of great importance to have the knowledge of thermal, temperature, thermo-mechanical and heat distribution on the workpiece in friction stir welding as this will help in designing process and the model parameters for welding application in the following welded joints, edge butt, lap, square butt, T lap, fillet, multiple lap etc. The physics of heat generation must be explored in order to understand the workability of friction stir welding (FSW). The FSW process begun with initial friction of mechanical that took place between the tool and the welded surface resulting in the generation of heat. Since the discovery of Friction Stir Welding (FSW) in 1991, many researchers have done tremendous investigations into the process and many experimental, theoretical, numerical, empirical, computational and analytical methods have been carried out in order to analyse and optimize FSW and to understand the complex mechanism in friction stir welding at the same time to deal with effects of various parameters relating to thermal profile during the process of FSW

    Numerical Modelling and Simulation of Metal Processing

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    This book deals with metal processing and its numerical modelling and simulation. In total, 21 papers from different distinguished authors have been compiled in this area. Various processes are addressed, including solidification, TIG welding, additive manufacturing, hot and cold rolling, deep drawing, pipe deformation, and galvanizing. Material models are developed at different length scales from atomistic simulation to finite element analysis in order to describe the evolution and behavior of materials during thermal and thermomechanical treatment. Materials under consideration are carbon, Q&T, DP, and stainless steels; ductile iron; and aluminum, nickel-based, and titanium alloys. The developed models and simulations shall help to predict structure evolution, damage, and service behavior of advanced materials

    In situ interlayer hot forging arc-based directed energy deposition of Inconel® 625: process development and microstructure effects

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    The typical as-built coarse and cube-oriented microstructure of Inconel® 625 parts fabricated via arc-based directed energy deposition (DED) induces anisotropic mechanical behavior, reducing the potential applications of arc-based DEDed Inconel® 625 in critical components. In this sense, the present work aimed to reduce the grain size and texture by applying an in situ interlayer hot forging (HF) combined with post-deposition heat treatments (PDHT). The produced samples were characterized through optical microscopy, scanning electron microscopy coupled with electron backscatter diffraction, synchrotron X-ray diffraction, and Vickers microhardness. Also, a dedicated deformation tool was designed and optimized via a finite element method model considering the processing conditions and thermal cycle experienced by the material. It is shown that the in situ interlayer deformation induced a thermo-mechanical-affected zone (dynamic recrystallized + remaining deformation, with a height of ˜ 1.2 mm) at the bead top surface, which resulted in thinner aligned grains and lower texture index in relation to as-built DED counterpart. In addition, the effects of solution (1100 °C/ 1 h) and stabilization (980 °C/ 1 h) PDHTs on the Inconel® 625 HF-DEDed parts were also analyzed, which promoted fine and equiaxed static recrystallized grains without cube orientation, comparable to wrought material. Therefore, the HF-DED process significantly refined the typical coarse and highly oriented microstructure of Ni-based superalloys obtained by arc-based DED.Peer ReviewedPostprint (published version

    process development and microstructure effects

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    JPO acknowledges funding by national funds from FCT - Fundação para a Ciência e a Tecnologia, Portugal, I.P. in the scope of the project LA/P/0037/2020. The authors acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for the provision of experimental facilities. Beamtime was allocated for proposal I-20210986 EC. This activity has received funding from the European Institute of Innovation and Technology (EIT) Raw Materials through the project Smart WAAM: Microstructural Engineering and Integrated Non-Destructive Testing. YZ acknowledges the National Natural Science Foundation of China (51601091), the Natural Science Foundation of Jiangsu Province (BK 20160826), the Six Talent Peaks Project of Jiangsu Province (2017-XCL-051), the Fundamental Research Funds for the Central Universities (30917011106), and Key Research and Development Plan of Jiangsu Province (BE 2020085). Funding Information: Authors acknowledge the Portuguese Fundação para a Ciência e a Tecnologia (FCT – MCTES) , Portugal, for its financial support via the project UID/EMS/00667/2019 (UNIDEMI). JPO acknowledges funding by national funds from FCT - Fundação para a Ciência e a Tecnologia, Portugal, I.P., in the scope of the projects LA/P/0037/2020 , UIDP/50025/2020 and UIDB/50025/2020 of the Associate Laboratory Institute of Nanostructures, Nanomodelling and Nanofabrication – i3N. FWCF acknowledges Fundação para a Ciência e a Tecnologia ( FCT-MCTES ), Portugal, for funding the Ph.D. Grant 2022.13870. BD . The authors acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for the provision of experimental facilities. Beamtime was allocated for proposal I-20210986 EC. The research leading to this result has been supported by the project CALIPSOplus under the Grant Agreement 730872 from the EU Framework Programme for Research and Innovation HORIZON 2020. This activity has received funding from the European Institute of Innovation and Technology (EIT) Raw Materials through the project Smart WAAM: Microstructural Engineering and Integrated Non-Destructive Testing. YZ acknowledges the National Natural Science Foundation of China (51601091), the Natural Science Foundation of Jiangsu Province (BK 20160826), the Six Talent Peaks Project of Jiangsu Province (2017-XCL-051), the Fundamental Research Funds for the Central Universities (30917011106), and Key Research and Development Plan of Jiangsu Province (BE 2020085). Publisher Copyright: © 2023 The AuthorsThe typical as-built coarse and cube-oriented microstructure of Inconel® 625 parts fabricated via arc-based directed energy deposition (DED) induces anisotropic mechanical behavior, reducing the potential applications of arc-based DEDed Inconel® 625 in critical components. In this sense, the present work aimed to reduce the grain size and texture by applying an in situ interlayer hot forging (HF) combined with post-deposition heat treatments (PDHT). The produced samples were characterized through optical microscopy, scanning electron microscopy coupled with electron backscatter diffraction, synchrotron X-ray diffraction, and Vickers microhardness. Also, a dedicated deformation tool was designed and optimized via a finite element method model considering the processing conditions and thermal cycle experienced by the material. It is shown that the in situ interlayer deformation induced a thermo-mechanical-affected zone (dynamic recrystallized + remaining deformation, with a height of ≈ 1.2 mm) at the bead top surface, which resulted in thinner aligned grains and lower texture index in relation to as-built DED counterpart. In addition, the effects of solution (1100 °C/ 1 h) and stabilization (980 °C/ 1 h) PDHTs on the Inconel® 625 HF-DEDed parts were also analyzed, which promoted fine and equiaxed static recrystallized grains without cube orientation, comparable to wrought material. Therefore, the HF-DED process significantly refined the typical coarse and highly oriented microstructure of Ni-based superalloys obtained by arc-based DED.publishersversionpublishe
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