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J. Manuf. Mater. Process., Volume 8, Issue 1 (February 2024) – 42 articles

Cover Story (view full-size image): Multi-Material Jetting yields high precision in additive manufacturing of ceramics and metals, but it poses challenges in the choice of building strategies, as improper droplet overlap affects the process stability. The study addresses classification of process parameterization based on in-line surface measurements on green parts and processing with machine learning methods, in particular convolutional neural networks. Demo parts printed with different overlaps are scanned and labeled. Models with two convolutional layers and a pooling size of (6, 6) yield the best accuracies. Models trained only with images of the first layer obtained validation accuracies of 90%. Consequently, an arbitrary section of the first layer is sufficient to deliver a prediction about the quality of subsequently printed layers. View this paper
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17 pages, 4514 KiB  
Article
Effect of Liquid Miscibility Gap on Defects in Inconel 625–GRCop42 Joints through Analysis of Gradient Composition Microstructure
by Jakub Preis, Donghua Xu, Brian K. Paul, Peter A. Eschbach and Somayeh Pasebani
J. Manuf. Mater. Process. 2024, 8(1), 42; https://doi.org/10.3390/jmmp8010042 - 14 Feb 2024
Viewed by 1264
Abstract
Joining of Cu-based dispersion-strengthened alloys to Ni-based superalloys has garnered increased attention for liquid rocket engine applications due to the high thermal conductivity of Cu-based alloys and high temperature tensile strength of Ni-based superalloys. However, such joints can suffer from cracking when joined [...] Read more.
Joining of Cu-based dispersion-strengthened alloys to Ni-based superalloys has garnered increased attention for liquid rocket engine applications due to the high thermal conductivity of Cu-based alloys and high temperature tensile strength of Ni-based superalloys. However, such joints can suffer from cracking when joined via liquid state processes, leading to part failure. In this work, compositions of 15–95 wt.% GRCop42 are alloyed with Inconel 625 and characterized to better understand the root cause of cracking. Results indicate a lack of miscibility between Cu-deprived and Cu-rich liquids in compositions corresponding to 30–95 wt.% GRCop42. Two distinct morphologies are observed and explained by use of CALPHAD; Cu-deprived dendrites with Cu-rich interdendritic zones at 30–50 wt.% GRCop42 and Cu-deprived spheres surrounded by a Cu-rich matrix at 60–95 wt.% GRCop42. Phase analysis reveals brittle intermetallic phases precipitate in the 60–95 wt.% GRCop42 Cu-deprived region. Three cracking mechanisms are proposed herein that provide guidance on the avoidance of defects Ni-based superalloy to Cu-based dispersion strengthened alloy joints. Full article
(This article belongs to the Special Issue Joining of Unweldable Materials: Concepts, Techniques and Processes)
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16 pages, 7266 KiB  
Article
Exploring New Parameters to Advance Surface Roughness Prediction in Grinding Processes for the Enhancement of Automated Machining
by Mohammadjafar Hadad, Samareh Attarsharghi, Mohsen Dehghanpour Abyaneh, Parviz Narimani, Javad Makarian, Alireza Saberi and Amir Alinaghizadeh
J. Manuf. Mater. Process. 2024, 8(1), 41; https://doi.org/10.3390/jmmp8010041 - 14 Feb 2024
Cited by 1 | Viewed by 1227
Abstract
Extensive research in smart manufacturing and industrial grinding has targeted the enhancement of surface roughness for diverse materials including Inconel alloy. Recent studies have concentrated on the development of neural networks, as a subcategory of machine learning techniques, to predict non-linear roughness behavior [...] Read more.
Extensive research in smart manufacturing and industrial grinding has targeted the enhancement of surface roughness for diverse materials including Inconel alloy. Recent studies have concentrated on the development of neural networks, as a subcategory of machine learning techniques, to predict non-linear roughness behavior in relation to various parameters. Nonetheless, this study introduces a novel set of parameters that have previously been unexplored, contributing to the advancement of surface roughness prediction for the grinding of Inconel 738 superalloy considering the effects of dressing and grinding parameters. Hence, the current study encompasses the utilization of a deep artificial neural network to forecast roughness. This implementation leverages an extensive dataset generated in a recent experimental study by the authors. The dataset comprises a multitude of process parameters across diverse conditions, including dressing techniques such as four-edge and single-edge diamond dresser, alongside cooling approaches like minimum quantity lubrication and conventional wet techniques. To evaluate a robust algorithm, a method is devised that involves different networks utilizing various activation functions and neuron sizes to distinguish and select the best architecture for this study. To gauge the accuracy of the methods, mean squared error and absolute accuracy metrics are applied, yielding predictions that fall within acceptable ranges for real-world industrial roughness standards. The model developed in this work has the potential to be integrated with the Industrial Internet of Things to further enhance automated machining. Full article
(This article belongs to the Special Issue Industry 4.0: Manufacturing and Materials Processing)
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42 pages, 11611 KiB  
Review
Negative Thermal Expansion Metamaterials: A Review of Design, Fabrication, and Applications
by Devashish Dubey, Anooshe Sadat Mirhakimi and Mohamed A. Elbestawi
J. Manuf. Mater. Process. 2024, 8(1), 40; https://doi.org/10.3390/jmmp8010040 - 14 Feb 2024
Viewed by 2036
Abstract
Most materials conventionally found in nature expand with an increase in temperature. In actual systems and assemblies like precision instruments, this can cause thermal distortions which can be difficult to handle. Materials with a tendency to shrink with an increase in temperature can [...] Read more.
Most materials conventionally found in nature expand with an increase in temperature. In actual systems and assemblies like precision instruments, this can cause thermal distortions which can be difficult to handle. Materials with a tendency to shrink with an increase in temperature can be used alongside conventional materials to restrict the overall dimensional change of structures. Such structures, also called negative-thermal-expansion materials, could be crucial in applications like electronics, biomedicine, aerospace components, etc., which undergo high changes in temperature. This can be achieved using mechanically engineered materials, also called negative thermal expansion (NTE) mechanical metamaterials. Mechanical metamaterials are mechanically architected materials with novel properties that are rare in naturally occurring materials. NTE metamaterials utilize their artificially engineered architecture to attain the rare property of negative thermal expansion. The emergence of additive manufacturing has enabled the feasible production of their intricate architectures. Industrial processes such as laser powder bed fusion and direct energy deposition, both utilized in metal additive manufacturing, have proven successful in creating complex structures like lattice formations and multimaterial components in the industrial sector, rendering them suitable for manufacturing NTE structures. Nevertheless, this review examines a range of fabrication methods, encompassing both additive and traditional techniques, and explores the diverse materials used in the process. Despite NTE metamaterials being a prominent field of research, a comprehensive review of these architected materials is missing in the literature. This article aims to bridge this gap by providing a state-of-the-art review of these metamaterials, encompassing their design, fabrication, and cutting-edge applications. Full article
(This article belongs to the Topic Additive Manufacturing of Architected Metallic Materials)
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13 pages, 12564 KiB  
Article
Fabrication of an Optically Transparent Planar Inverted-F Antenna Using PEDOT-Based Silver Nanowire Clear Ink with Aerosol-Jet Printing Method towards Effective Antennas
by Philip Li, Jason Fleischer, Edwin Quinn and Donghun Park
J. Manuf. Mater. Process. 2024, 8(1), 39; https://doi.org/10.3390/jmmp8010039 - 10 Feb 2024
Viewed by 1155
Abstract
We report the design, fabrication, and experimental characterization of an optically transparent printed planar inverted-F antenna (PIFA) operating at 2.45 GHz using the aerosol jet (AJ) printing method. The proposed antenna was fabricated using a clear conductive ink on glass and Delrin. The [...] Read more.
We report the design, fabrication, and experimental characterization of an optically transparent printed planar inverted-F antenna (PIFA) operating at 2.45 GHz using the aerosol jet (AJ) printing method. The proposed antenna was fabricated using a clear conductive ink on glass and Delrin. The antenna exhibits a wide fractional bandwidth (FBW) of 20% centered at 2.45 GHz, with a peak realized gain of −3.6 dBi and transparency of ~80%. The proposed fabrication method provides a cost-effective and scalable solution for manufacturing transparent antennas with potential applications in wireless communication, sensing, and wearable devices operating at mmWave frequencies higher than 30 GHz. Full article
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14 pages, 4900 KiB  
Article
The Effect of Niobium Addition on the Operational and Metallurgical Behavior of Fe-Cr-C Hardfacing Deposited by Shielded Metal Arc Welding
by Jaime Perez, Jesus Gutierrez, Jhon Olaya, Oscar Piamba and Americo Scotti
J. Manuf. Mater. Process. 2024, 8(1), 38; https://doi.org/10.3390/jmmp8010038 - 10 Feb 2024
Viewed by 1198
Abstract
Hardfacing is commonly used in parts recovery and in obtaining surfaces with improved properties. Within this field, it is important to analyze the effect of alloying elements on the properties of the deposited layers. One of the critical parameters affecting alloying performances in [...] Read more.
Hardfacing is commonly used in parts recovery and in obtaining surfaces with improved properties. Within this field, it is important to analyze the effect of alloying elements on the properties of the deposited layers. One of the critical parameters affecting alloying performances in SMAW is improper arc length. This article examines the effect of the addition of niobium in different quantities (0, 2, 4, 6, and 8% by weight) to the electrode coating in Fe-Cr-C shielded metal arc welding (SMAW), with short and long arc lengths, on the operational process efficiency, dilution, arc energy, microstructure, and microhardness of the deposited layers. A decrease in operational process efficiency and dilution was found with increases in niobium content. On the other hand, it was found that adding niobium leads to a refinement in chromium carbide sizes, directly affecting the hardness of the obtained deposits. There is a direct relationship between the arc energy, with both short and long arc lengths, leading to a tendency to decrease the dilution in the obtained hardfacing. Full article
(This article belongs to the Special Issue Advances in Welding Technology)
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46 pages, 12054 KiB  
Review
INCONEL® Alloy Machining and Tool Wear Finite Element Analysis Assessment: An Extended Review
by André F. V. Pedroso, Naiara P. V. Sebbe, Rúben D. F. S. Costa, Marta L. S. Barbosa, Rita C. M. Sales-Contini, Francisco J. G. Silva, Raul D. S. G. Campilho and Abílio M. P. de Jesus
J. Manuf. Mater. Process. 2024, 8(1), 37; https://doi.org/10.3390/jmmp8010037 - 09 Feb 2024
Cited by 1 | Viewed by 1385
Abstract
Machining INCONEL® presents significant challenges in predicting its behaviour, and a comprehensive experimental assessment of its machinability is costly and unsustainable. Design of Experiments (DOE) can be conducted non-destructively through Finite Element Analysis (FEA). However, it is crucial to ascertain whether numerical [...] Read more.
Machining INCONEL® presents significant challenges in predicting its behaviour, and a comprehensive experimental assessment of its machinability is costly and unsustainable. Design of Experiments (DOE) can be conducted non-destructively through Finite Element Analysis (FEA). However, it is crucial to ascertain whether numerical and constitutive models can accurately predict INCONEL® machining. Therefore, a comprehensive review of FEA machining strategies is presented to systematically summarise and analyse the advancements in INCONEL® milling, turning, and drilling simulations through FEA from 2013 to 2023. Additionally, non-conventional manufacturing simulations are addressed. This review highlights the most recent modelling digital solutions, prospects, and limitations that researchers have proposed when tackling INCONEL® FEA machining. The genesis of this paper is owed to articles and books from diverse sources. Conducting simulations of INCONEL® machining through FEA can significantly enhance experimental analyses with the proper choice of damage and failure criteria. This approach not only enables a more precise calibration of parameters but also improves temperature (T) prediction during the machining process, accurate Tool Wear (TW) quantity and typology forecasts, and accurate surface quality assessment by evaluating Surface Roughness (SR) and the surface stress state. Additionally, it aids in making informed choices regarding the potential use of tool coatings. Full article
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28 pages, 2185 KiB  
Article
A Systematic Method for Assessing the Machine Performance of Material Extrusion Printers
by Laurent Spitaels, Endika Nieto Fuentes, Edouard Rivière-Lorphèvre, Pedro-José Arrazola and François Ducobu
J. Manuf. Mater. Process. 2024, 8(1), 36; https://doi.org/10.3390/jmmp8010036 - 09 Feb 2024
Viewed by 1206
Abstract
The performance assessment of additive manufacturing (AM) printers is still a challenge since no dedicated standard exists. This paper proposes a systematic method for evaluating the dimensional and geometrical performance of such machines using the concept of machine performance. The method was applied [...] Read more.
The performance assessment of additive manufacturing (AM) printers is still a challenge since no dedicated standard exists. This paper proposes a systematic method for evaluating the dimensional and geometrical performance of such machines using the concept of machine performance. The method was applied to an Ultimaker 2+ printer producing parts with polylactic acid (PLA). The X and Y axes of the printer were the most performant and led to narrower potential and real tolerance intervals than the Z axis. The proposed systematic framework can be used to assess the performance of any material extrusion printer and its achievable tolerance intervals. Full article
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18 pages, 11154 KiB  
Article
Influence of the Processing Parameters on the Microstructure and Mechanical Properties of 316L Stainless Steel Fabricated by Laser Powder Bed Fusion
by Germán Omar Barrionuevo, Jorge Andrés Ramos-Grez, Xavier Sánchez-Sánchez, Daniel Zapata-Hidalgo, José Luis Mullo and Santiago D. Puma-Araujo
J. Manuf. Mater. Process. 2024, 8(1), 35; https://doi.org/10.3390/jmmp8010035 - 09 Feb 2024
Viewed by 1618
Abstract
Complex thermo-kinetic interactions during metal additive manufacturing reduce the homogeneity of the microstructure of the produced samples. Understanding the effect of processing parameters over the resulting mechanical properties is essential for adopting and popularizing this technology. The present work is focused on the [...] Read more.
Complex thermo-kinetic interactions during metal additive manufacturing reduce the homogeneity of the microstructure of the produced samples. Understanding the effect of processing parameters over the resulting mechanical properties is essential for adopting and popularizing this technology. The present work is focused on the effect of laser power, scanning speed, and hatch spacing on the relative density, microhardness, and microstructure of 316L stainless steel processed by laser powder bed fusion. Several characterization techniques were used to study the microstructure and mechanical properties: optical, electron microscopies, and spectrometry. A full-factorial design of experiments was employed for relative density and microhardness evaluation. The results derived from the experimental work were subjected to statistical analysis, including the use of analysis of variance (ANOVA) to determine both the main effects and the interaction between the processing parameters, as well as to observe the contribution of each factor on the mechanical properties. The results show that the scanning speed is the most statistically significant parameter influencing densification and microhardness. Ensuring the amount of volumetric energy density (125 J/mm3) used to melt the powder bed is paramount; maximum densification (99.7%) is achieved with high laser power and low scanning speed, while hatch spacing is not statistically significant. Full article
(This article belongs to the Special Issue Laser-Based Manufacturing II)
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23 pages, 10146 KiB  
Article
Experimental Characterization of Screw-Extruded Carbon Fibre-Reinforced Polyamide: Design for Aeronautical Mould Preforms with Multiphysics Computational Guidance
by Juan Carlos Antolin-Urbaneja, Haritz Vallejo Artola, Eduard Bellvert Rios, Jorge Gayoso Lopez, Jose Ignacio Hernández Vicente and Ana Isabel Luengo Pizarro
J. Manuf. Mater. Process. 2024, 8(1), 34; https://doi.org/10.3390/jmmp8010034 - 09 Feb 2024
Viewed by 1309
Abstract
In this research work, the suitability of short carbon fibre-reinforced polyamide 6 in pellet form for printing an aeronautical mould preform with specific thermomechanical requirements is investigated. This research study is based on an extensive experimental characterization campaign, in which the principal mechanical [...] Read more.
In this research work, the suitability of short carbon fibre-reinforced polyamide 6 in pellet form for printing an aeronautical mould preform with specific thermomechanical requirements is investigated. This research study is based on an extensive experimental characterization campaign, in which the principal mechanical properties of the printed material are determined. Furthermore, the temperature dependency of the material properties is characterized by testing samples at different temperatures for bead printing and stacking directions. Additionally, the thermal properties of the material are characterized, including the coefficient of thermal expansion. Moreover, the influence of printing machine parameters is evaluated by comparing the obtained tensile moduli and strengths of several manufactured samples at room temperature. The results show that the moduli and strengths can vary from 78% to 112% and from 55% to 87%, respectively. Based on a real case study of its aeronautical use and on the experimental data from the characterization stage, a new mould design is iteratively developed with multiphysics computational guidance, considering 3D printing features and limitations. Specific design drivers are identified from the observed material’s thermomechanical performance. The designed mould, whose mass is reduced around 90% in comparison to that of the original invar design, is numerically proven to fulfil thermal and mechanical requirements with a high performance. Full article
(This article belongs to the Topic Advanced Composites Manufacturing and Plastics Processing)
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15 pages, 4855 KiB  
Article
Modeling the Thermoforming Process of a Complex Geometry Based on a Thermo-Visco-Hyperelastic Model
by Ameni Ragoubi, Guillaume Ducloud, Alban Agazzi, Patrick Dewailly and Ronan Le Goff
J. Manuf. Mater. Process. 2024, 8(1), 33; https://doi.org/10.3390/jmmp8010033 - 08 Feb 2024
Viewed by 1345
Abstract
The thermoforming process is commonly used in industry for the manufacturing of lightweight, thin-walled products from a pre-extruded polymer sheet. Many simulations have been developed to simulate the process and optimize it with computer tools. The development of testing machines has simplified the [...] Read more.
The thermoforming process is commonly used in industry for the manufacturing of lightweight, thin-walled products from a pre-extruded polymer sheet. Many simulations have been developed to simulate the process and optimize it with computer tools. The development of testing machines has simplified the simulation of this type of process, allowing researchers to characterize the behavior of the material at different temperatures and for large deformation to be closer to the real conditions of the process. This paper presents the results of a study on the modeling of the thermoforming process for an industrial demonstrator made from a high-impact polystyrene (HIPS) polymer. The HIPS shows a mechanical behavior that depends on the temperature and strain rate. In such conditions, a thermo-hyper-viscoelastic constitutive model is used to replicate the thermoforming process of the industrial demonstrator using ABAQUS/Explicit. Its behavior is determined via various experimental tests: uniaxial tensile tests at different temperatures and strain rates and Dynamic Mechanical Analysis (DMA). A comparison between the numerical and experimental results is carried out for the evolution of film thickness. The paper concludes with a discussion of possible improvements to be considered for future simulations of the thermoforming process using Abaqus, which presents complex challenges in terms of contact and material modeling. Full article
(This article belongs to the Special Issue Advances in Material Forming)
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20 pages, 15512 KiB  
Article
Ultrasonic-Vibration-Superimposed Face Turning of Aluminium Matrix Composite Components for Enhancing Friction-Surface Preconditioning
by Patrick Eiselt, Sarah Johanna Hirsch, Ismail Ozdemir, Andreas Nestler, Thomas Grund, Andreas Schubert and Thomas Lampke
J. Manuf. Mater. Process. 2024, 8(1), 32; https://doi.org/10.3390/jmmp8010032 - 07 Feb 2024
Viewed by 1241
Abstract
Aluminium matrix composites (AMCs) represent an important group of high-performance materials. Due to their specific strength and a high thermal conductivity, these composites have been considered for the large-scale production of brake discs. However, preconditioning the friction surfaces is necessary to avoid severe [...] Read more.
Aluminium matrix composites (AMCs) represent an important group of high-performance materials. Due to their specific strength and a high thermal conductivity, these composites have been considered for the large-scale production of brake discs. However, preconditioning the friction surfaces is necessary to avoid severe wear of both the brake discs and the brake linings. This can be achieved through controlled friction against commercially available brake-lining materials and the formation of transfer or reactive layers (tribosurfaces). Homogeneous tribosurfaces allow for nearly wear-free brake systems under moderate brake conditions. In this work, preconditioning was carried out with a pin-on-disc tester, aiming for the fast creation of homogeneously formed and stable tribosurfaces. The influence of surface microedges perpendicular to the direction of friction on the machined AMC surfaces on the build-up speed and homogeneity of the tribosurfaces was investigated. The microedges were generated using ultrasonic-vibration-superimposed face turning. Thereby, the vibration direction corresponded to the direction of the passive force. For research purposes, the distance of the microedges was changed by varying the cutting speed and feed. The experiments were carried out using AMC disc specimens with a reinforcement content of a 35% volume proportion of silicon carbide particles. Machining was realised with CVD-diamond-tipped indexable inserts. The evaluation of the generated surfaces before and after preconditioning was achieved using 3D laser scanning microscopy and scanning electron microscopy. It was demonstrated that ultrasonic-vibration-superimposed face turning effectively generated microedges on the AMC surfaces. The results show that larger distances between the microedges enhanced the formation of stable tribosurfaces. Thus, the tribosystem’s steady state was reached quickly. Therefore, the benefits of AMC-friction-surface microstructuring on the generation of tribosurfaces under laboratory conditions were proven. These findings contribute to the development of high-performance AMC brake systems. Full article
(This article belongs to the Special Issue Advances in Machining of Difficult-to-Cut Materials)
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30 pages, 18862 KiB  
Article
Numerical Model of Simultaneous Multi-Regime Boiling Quenching of Metals
by Marco Antonio González-Melo, Omar Alonso Rodríguez-Rodríguez, Bernardo Hernández-Morales and Francisco Andrés Acosta-González
J. Manuf. Mater. Process. 2024, 8(1), 31; https://doi.org/10.3390/jmmp8010031 - 06 Feb 2024
Viewed by 1125
Abstract
This work presents a heat transfer and boiling model that computes the evolution of the temperature field in a representative steel workpiece quenched from 850 or 930 °C by immersion in water flowing at average velocities of 0.2 or 0.6 m/s, respectively. Under [...] Read more.
This work presents a heat transfer and boiling model that computes the evolution of the temperature field in a representative steel workpiece quenched from 850 or 930 °C by immersion in water flowing at average velocities of 0.2 or 0.6 m/s, respectively. Under these conditions, all three boiling regimes were present during cooling: stable vapor film, nucleate boiling, and single-phase convection. The model was based on the numerical solution of the heat conduction equation coupled to the solution of the energy and momentum equations for water. The mixture phase approach was adopted using the Lee model to compute the rates of water evaporation–condensation. Heat flux at the wall was calculated for all regimes using a single semi-mechanistic model. Therefore, the evolution of boiling regimes at every position on the wall surface was automatically determined. Predictions were validated using laboratory results, namely: (a) videorecording the upward motion of the wetting front along the workpiece wall surface; and (b) cooling curves obtained with embedded thermocouples in the steel probe. Wall heat flux calculations were used to determine the importance of the simultaneous presence of all three boiling regimes on the heat flux distribution. It was found that this simultaneous presence leads to high heat flux variations that should be avoided in production lines. In addition, it was determined that the corresponding inverse heat conduction problem to estimate the active heat transfer boundary condition must be set-up for 2D heat flow. Full article
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16 pages, 19166 KiB  
Article
Deep Container Fabrication by Forging with High- and Low-Density Wood
by Hinako Uejima, Takashi Kuboki, Soichi Tanaka and Shohei Kajikawa
J. Manuf. Mater. Process. 2024, 8(1), 30; https://doi.org/10.3390/jmmp8010030 - 06 Feb 2024
Viewed by 1146
Abstract
This paper presents a method for applying forging to high-density wood. A cylindrical container was formed using a closed die, and the appropriate conditions for temperature and punch length were evaluated. Ulin, which is a high-density wood, and Japanese cedar, which is a [...] Read more.
This paper presents a method for applying forging to high-density wood. A cylindrical container was formed using a closed die, and the appropriate conditions for temperature and punch length were evaluated. Ulin, which is a high-density wood, and Japanese cedar, which is a low-density wood and widely used in Japan, were used as test materials. The pressing directions were longitudinal and radial based on wood fiber orientation, and the shape and density of the resulting containers were evaluated. In the case of ulin, cracks decreased by increasing the temperature, while temperature had little effect on Japanese cedar. Containers without cracks were successfully formed by using a punch of appropriate length. The density of the containers was uniform in the punch length l = 20 and 40 mm in the L-directional pressing and l = 20 mm in the R-directional pressing when using ulin, with an average density of 1.34 g/cm3. This result indicates the forging ability of ulin is high compared to that of commonly used low-density woods. In summary, this paper investigated the appropriate parameters for forging with ulin. As a result, products of more uniform density than products made by cutting were obtained. Full article
(This article belongs to the Special Issue Advances in Material Forming)
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17 pages, 15029 KiB  
Article
Exploring a Novel Material and Approach in 3D-Printed Wrist-Hand Orthoses
by Diana Popescu, Mariana Cristiana Iacob, Cristian Tarbă, Dan Lăptoiu and Cosmin Mihai Cotruţ
J. Manuf. Mater. Process. 2024, 8(1), 29; https://doi.org/10.3390/jmmp8010029 - 05 Feb 2024
Viewed by 1245
Abstract
This article proposes the integration of two novel aspects into the production of 3D-printed customized wrist-hand orthoses. One aspect involves the material, particularly Colorfabb varioShore thermoplastic polyurethane (TPU) filament with an active foaming agent, which allows adjusting the 3D-printed orthoses’ mechanical properties via [...] Read more.
This article proposes the integration of two novel aspects into the production of 3D-printed customized wrist-hand orthoses. One aspect involves the material, particularly Colorfabb varioShore thermoplastic polyurethane (TPU) filament with an active foaming agent, which allows adjusting the 3D-printed orthoses’ mechanical properties via process parameters such as printing temperature. Consequently, within the same printing process, by using a single extrusion nozzle, orthoses with varying stiffness levels can be produced, aiming at both immobilization rigidity and skin-comfortable softness. This capability is harnessed by 3D-printing the orthosis in a flat shape via material extrusion-based additive manufacturing, which represents the other novel aspect. Subsequently, the orthosis conforms to the user’s upper limb shape after secure attachment, or by thermoforming in the case of a bi-material solution. A dedicated design web app, which relies on key patient hand measurement input, is also proposed, differing from the 3D scanning and modeling approach that requires engineering expertise and 3D scan data processing. The evaluation of varioShore TPU orthoses with diverse designs was conducted considering printing time, cost, maximum flexion angle, comfort, and perceived wrist stability as criteria. As some of the produced TPU orthoses lacked the necessary stiffness around the wrist or did not properly fit the palm shape, bi-material orthoses including polylactic acid (PLA) inserts of varying sizes were 3D-printed and assessed, showing an improved stiffness around the wrist and a better hand shape conformity. The findings demonstrated the potential of this innovative approach in creating bi-material upper limb orthoses, capitalizing on various characteristics such as varioShore properties, PLA thermoforming capabilities, and the design flexibility provided by additive manufacturing technology. Full article
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8 pages, 3566 KiB  
Communication
Cemented Carbide End-Mill Edge Preparation Using Dry-Electropolishing
by Guiomar Riu-Perdrix, Andrea Valencia-Cadena, Luis Llanes and Joan Josep Roa
J. Manuf. Mater. Process. 2024, 8(1), 28; https://doi.org/10.3390/jmmp8010028 - 03 Feb 2024
Viewed by 1199
Abstract
Precision edge preparation techniques for cemented carbides enable optimization of the geometry of tools’ cutting edges. These techniques are frequently used in high-stress environments, resulting in substantial improvements in tools’ cutting performance. This investigation examined the impact and evolution of cutting edge parameters [...] Read more.
Precision edge preparation techniques for cemented carbides enable optimization of the geometry of tools’ cutting edges. These techniques are frequently used in high-stress environments, resulting in substantial improvements in tools’ cutting performance. This investigation examined the impact and evolution of cutting edge parameters and resulting surface finishes as a function of dry-electropolishing time on an end-mill. Findings demonstrate enlargement of the cutting edge radius, a decrease in surface roughness, and the mitigation of defects induced during previous manufacturing stages (i.e., smashed ceramic particles, burrs, chipping, etc.). Additionally, a direct correlation between dry-electropolishing time and primary cutting edges’ micro-geometry parameters has been established. Full article
(This article belongs to the Special Issue Advances in Metal Cutting and Cutting Tools)
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19 pages, 6321 KiB  
Article
On the Influence of Wave-Shaped Tool Path Strategies on Geometric Accuracy in Incremental Sheet Forming
by Thomas Bremen and David Benjamin Bailly
J. Manuf. Mater. Process. 2024, 8(1), 27; https://doi.org/10.3390/jmmp8010027 - 01 Feb 2024
Viewed by 1061
Abstract
In incremental sheet forming (ISF), the geometrical accuracy is still a challenge that is only solved for specific applications. The underlying mechanisms of geometrical defects in ISF are very complex and still not fully understood. Nevertheless, the process understanding is constantly evolving. Recent [...] Read more.
In incremental sheet forming (ISF), the geometrical accuracy is still a challenge that is only solved for specific applications. The underlying mechanisms of geometrical defects in ISF are very complex and still not fully understood. Nevertheless, the process understanding is constantly evolving. Recent work has shown, for example, how bending moments resulting from residual stresses affect geometric accuracy. It has become clear that resulting bending moments with an axis parallel to the main tool path direction are dominant. Based on that, the current paper investigates the hypothesis that linear and parallel tool paths lead to an unfavourable accumulation of residual bending moments along a common axis, and whether this accumulation effect can be reduced by wave-shaped tool paths. Thus, the described research investigates the influence of novel path strategies on the residual bending moments and the resulting geometrical deviations. The path strategies are based on wave-shaped path lines, whereas the curvature is within the sheet plane. The investigations focussed on a rectangular sheet that is clamped at its shortest edges and a part geometry-sensitive to springback. Experimental and numerical investigations show a significantly positive influence of some investigated path strategies on the geometric deviation, compared to a conventional path strategy. Full article
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18 pages, 5297 KiB  
Article
Creation of an Aluminum Alloy Template with a Surface Structure by Micro-Milling for Subsequent Replication of the Microstructure to Achieve Hydrophobicity
by Artur Knap, Štěpánka Dvořáčková and Martin Váňa
J. Manuf. Mater. Process. 2024, 8(1), 26; https://doi.org/10.3390/jmmp8010026 - 01 Feb 2024
Viewed by 1170
Abstract
This research paper focuses on the fabrication of a microstructure based on a natural structure pattern of hydrophobic properties using micro-milling technology, followed by an investigation of the dimensional accuracy, roughness, and replication of the fabricated microstructure. Design, modeling (CAD system), fabrication, and [...] Read more.
This research paper focuses on the fabrication of a microstructure based on a natural structure pattern of hydrophobic properties using micro-milling technology, followed by an investigation of the dimensional accuracy, roughness, and replication of the fabricated microstructure. Design, modeling (CAD system), fabrication, and replication are the steps of this process. Knowledge of biomimetics was used to select the microstructure. The main research aim of the experiments is to verify and extend the applicability of conventional CNC manufacturing technologies to obtain a functional surface structure. The micro-milling was carried out on a conventional DMG MORI CNC machine, a CMX 600 V three-axis horizontal milling center, using an external high-frequency electric spindle clamped to the machine. The machined material was aluminum alloy EN AW 7075. The tool was a 0.1 mm diameter double-edged ball mill made of sintered carbide and coated with TiSiN. The cutting conditions were determined according to the tool manufacturer’s recommendations. To compare the achieved accuracies, the same microstructure was fabricated using PLA technology. For subsequent replication of the sample, the negative of the selected microstructure was created and machined. Subsequently, a positive microstructure was created using the silicone impression material by the replication process. This paper and the experiments performed extend the technical knowledge in the field of manufacturing surface functional structures and confirm the possibility of manufacturing the designed structures using chip and laser machining technology, with achieved discontinuities in the range of 3 to 50 μm. They also highlight the issues of replication of such structures with respect to critical manufacturing locations (geometrical parameters of the structures affecting the functional properties of the structure, venting, replica defects, etc.). Full article
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20 pages, 15289 KiB  
Article
Processing and Analysis of Hybrid Fiber-Reinforced Polyamide Composite Structures Made by Fused Granular Fabrication and Automated Tape Laying
by Patrick Hirsch, Simon Scholz, Benjamin Borowitza, Moritz Vyhnal, Ralf Schlimper, Matthias Zscheyge, Ondrej Kotera, Michaela Stipkova and Sebastian Scholz
J. Manuf. Mater. Process. 2024, 8(1), 25; https://doi.org/10.3390/jmmp8010025 - 01 Feb 2024
Viewed by 1376
Abstract
Fused granular fabrication (FGF) is a large format additive manufacturing (LFAM) technology and focuses on cost-effective granulate-based manufacturing by eliminating the need for semifinished filaments. This allows a faster production time and a broader range of usable materials for tailored composites. In this [...] Read more.
Fused granular fabrication (FGF) is a large format additive manufacturing (LFAM) technology and focuses on cost-effective granulate-based manufacturing by eliminating the need for semifinished filaments. This allows a faster production time and a broader range of usable materials for tailored composites. In this study, the mechanical and morphological properties of FGF test structures made of polyamid 6 reinforced with 40% of short carbon fibers were investigated. For this purpose, FGF test structures with three different parameter settings were produced. The FGF printed structures show generally significant anisotropic mechanical characteristics, caused by the layer-by-layer building process. To enhance the mechanical properties and reduce the anisotropic behavior of FGF structures, continuous unidirectional fiber-reinforced tapes (UD tapes), employing automated tape laying (ATL), were subsequently applied. Thus, a significant improvement in the flexural stiffness and strength of the manufactured FGF structures was observed by hybridization with 60% glass fiber-reinforced polyamide 6 UD tapes. Since the effectiveness of UD-tape reinforcement depends mainly on the quality of the bond between the UD tape and the FGF structure, the surface quality of the FGF structure, the interface morphology, and the tape-laying process parameters were investigated. Full article
(This article belongs to the Topic Advanced Composites Manufacturing and Plastics Processing)
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14 pages, 7991 KiB  
Article
Investigation of Generatively Manufactured Components in a Sealed Welding Chamber Using the Tungsten Inert Gas Hot Wire Process
by Silvia Imrich, Kai Treutler and Volker Wesling
J. Manuf. Mater. Process. 2024, 8(1), 24; https://doi.org/10.3390/jmmp8010024 - 31 Jan 2024
Viewed by 1102
Abstract
To produce additively manufactured components, various process advantages can be combined by using the tungsten inert gas (TIG) hot wire process with ohmic wire preheating. Unlike other various gas metal arc welding processes, with TIG, it is possible to influence the material properties [...] Read more.
To produce additively manufactured components, various process advantages can be combined by using the tungsten inert gas (TIG) hot wire process with ohmic wire preheating. Unlike other various gas metal arc welding processes, with TIG, it is possible to influence the material properties by decoupling the energy supply and the welding filler material. Compared to the conventional TIG cold wire process, the hot wire process can achieve an increased deposition rate. To be able to use this combined process for the manufacturing of filigree components consisting of steel and titanium alloys, a system concept with a hermetically sealed welding chamber was developed. This concept is particularly designed for an individual use and is also intended to be used for producing prototypes and small quantities. In the investigations, the application of the TIG hot wire process is explored, regarding the material properties to be achieved in combination with the manufacturing plant concept developed with a sealed welding chamber. In this context, the mechanical-technological properties and detailed microstructural analyses are determined based on selected welding tests to evaluate and further develop the quality of the components produced. A final transfer of the findings to the process behavior by optimizing the interaction of the process parameters considered should lead to an increase in productivity, robustness, and reproducibility. The experimental setup’s potential for applicability in the field of additive manufacturing will be demonstrated based on this elaboration. Full article
(This article belongs to the Special Issue Advanced Joining Processes and Techniques 2023)
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37 pages, 7963 KiB  
Review
Advancements and Challenges in Additively Manufactured Functionally Graded Materials: A Comprehensive Review
by Suhas Alkunte, Ismail Fidan, Vivekanand Naikwadi, Shamil Gudavasov, Mohammad Alshaikh Ali, Mushfig Mahmudov, Seymur Hasanov and Muralimohan Cheepu
J. Manuf. Mater. Process. 2024, 8(1), 23; https://doi.org/10.3390/jmmp8010023 - 30 Jan 2024
Cited by 2 | Viewed by 2277
Abstract
This paper thoroughly examines the advancements and challenges in the field of additively manufactured Functionally Graded Materials (FGMs). It delves into conceptual approaches for FGM design, various manufacturing techniques, and the materials employed in their fabrication using additive manufacturing (AM) technologies. This paper [...] Read more.
This paper thoroughly examines the advancements and challenges in the field of additively manufactured Functionally Graded Materials (FGMs). It delves into conceptual approaches for FGM design, various manufacturing techniques, and the materials employed in their fabrication using additive manufacturing (AM) technologies. This paper explores the applications of FGMs in diverse fields, including structural engineering, automotive, biomedical engineering, soft robotics, electronics, 4D printing, and metamaterials. Critical issues and challenges associated with FGMs are meticulously analyzed, addressing concerns related to production and performance. Moreover, this paper forecasts future trends in FGM development, highlighting potential impacts on diverse industries. The concluding section summarizes key findings, emphasizing the significance of FGMs in the context of AM technologies. This review provides valuable insights to researchers, practitioners, and stakeholders, enhancing their understanding of FGMs and their role in the evolving landscape of AM. Full article
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30 pages, 10193 KiB  
Review
Review on the Application of the Attention Mechanism in Sensing Information Processing for Dynamic Welding Processes
by Jingyuan Xu, Qiang Liu, Yuqing Xu, Runquan Xiao, Zhen Hou and Shanben Chen
J. Manuf. Mater. Process. 2024, 8(1), 22; https://doi.org/10.3390/jmmp8010022 - 28 Jan 2024
Viewed by 1246
Abstract
Arc welding is the common method used in traditional welding, which constitutes the majority of total welding production. The traditional manual and manual teaching welding method has problems with high labor costs and limited efficiency when faced with mass production. With the advancement [...] Read more.
Arc welding is the common method used in traditional welding, which constitutes the majority of total welding production. The traditional manual and manual teaching welding method has problems with high labor costs and limited efficiency when faced with mass production. With the advancement in technology, intelligent welding technology is expected to become a solution to this problem in the future. To achieve the intelligent welding process, modern sensing technology can be employed to effectively simulate the welder’s sensory perception and cognitive abilities. Recent studies have advanced the application of sensing technologies, leading to the advancement in intelligent welding process. The review is divided into two aspects. First, the theory and applications of various sensing technologies (visual, sound, arc, spectral signal, etc.) are summarized. Then, combined with the generalization of neural networks and attention mechanisms, the development trends in welding sensing information processing and modeling technology are discussed. Based on the existing research results, the feasibility, advantages, and development direction of attention mechanisms in the welding field are analyzed. In the end, a brief conclusion and remarks are presented. Full article
(This article belongs to the Special Issue Industry 4.0: Manufacturing and Materials Processing)
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15 pages, 3569 KiB  
Article
Experimental Uncertainty Evaluation in Optical Measurements of Micro-Injection Molded Products
by Vincenzo Bellantone, Rossella Surace and Irene Fassi
J. Manuf. Mater. Process. 2024, 8(1), 21; https://doi.org/10.3390/jmmp8010021 - 26 Jan 2024
Viewed by 1198
Abstract
Optical measurements are increasingly widely used as preferential techniques to evaluate dimensional and surface quantities in micro-products. However, uncertainty estimation is more critical on micro-products than macro, and it needs careful attention for evaluating the obtained quality, the requested tolerance, and the correct [...] Read more.
Optical measurements are increasingly widely used as preferential techniques to evaluate dimensional and surface quantities in micro-products. However, uncertainty estimation is more critical on micro-products than macro, and it needs careful attention for evaluating the obtained quality, the requested tolerance, and the correct setting of experimental process settings. In this study, optical measurements characterized micro-injected products by linear and surface acquisition and considered all the sources contributing to uncertainties. The results show that the measure uncertainty could be underestimated if only the standard deviation on simple measurements is considered; this could cause a significant restriction of the estimated range covering the measured values. Furthermore, the findings confirm that the correct evaluation of the potential uncertainties contributes to accurately assessing the process behavior and improving product quality. Full article
(This article belongs to the Special Issue Advances in Injection Molding: Process, Materials and Applications)
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19 pages, 4541 KiB  
Article
Numerical Study of the Cold Metal Transfer (CMT) Welding of Thin Austenitic Steel Plates with an Equivalent Heat Source Approach
by Hichem Aberbache, Alexandre Mathieu, Nathan Haglon, Rodolphe Bolot, Laurent Bleurvacq, Axel Corolleur and Fabrice Laurent
J. Manuf. Mater. Process. 2024, 8(1), 20; https://doi.org/10.3390/jmmp8010020 - 26 Jan 2024
Viewed by 1635
Abstract
The CMT (cold metal transfer) arc welding process is a valuable joining method for assembling thin sheets, minimizing heat transfers, and reducing subsequent deformations. The study aims to simulate the CMT welding of thin stainless-steel sheets to predict temperature fields and deformations. Both [...] Read more.
The CMT (cold metal transfer) arc welding process is a valuable joining method for assembling thin sheets, minimizing heat transfers, and reducing subsequent deformations. The study aims to simulate the CMT welding of thin stainless-steel sheets to predict temperature fields and deformations. Both instrumented tests and numerical simulations were conducted for butt-welding of sheets with a thickness of 1 to 1.2 mm. Weld seam samples were observed to identify equivalent heat sources for each configuration. The electric current and voltage were monitored. Temperature measurements were performed using K-type thermocouples, as well as displacement measurements via the DIC (digital image correlation) technique. Thermomechanical simulations, considering phase changes and the actual seam geometry induced by filler material, were conducted using an equivalent heat source approach. A unique heat exchange coefficient accounting for thermal losses was identified. By incorporating these losses into thermal calculations, a good agreement was found between measured and calculated temperatures. Mechanical calculations allowed for the recovery of the horse saddle form after actual welding, with a relative difference of less than 10% in angular distortion between calculated and measured values. Full article
(This article belongs to the Special Issue Advanced Joining Processes and Techniques 2023)
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21 pages, 7850 KiB  
Article
Effect of Intermediate Path on Post-Wrinkle Initiation of the Multi-Pass Metal Spinning Process: Analysis in the Rotating Reference Frame
by Huy Hoan Nguyen, Henri Champliaud and Van Ngan Le
J. Manuf. Mater. Process. 2024, 8(1), 19; https://doi.org/10.3390/jmmp8010019 - 24 Jan 2024
Viewed by 1171
Abstract
The metal spinning process has been observed in recent major investigations carried out using finite element analysis. One interesting idea has proposed simulating a rotating disc for the simulation of the metal spinning process to reduce computational time. The development of this concept [...] Read more.
The metal spinning process has been observed in recent major investigations carried out using finite element analysis. One interesting idea has proposed simulating a rotating disc for the simulation of the metal spinning process to reduce computational time. The development of this concept is presented in this paper, including the formal mathematical transformation from the inertial frame to the rotating reference frame, specific FEM configurations with mesh sizes based on a minimized aspect ratio, a mesh convergence study, and the application of a feed rate scale. Furthermore, in the context of the rotating reference frame, the flange geometry after wrinkle initiation is investigated, including the number of peaks and their amplitudes. Using this new approach, it was found that the number of peaks gradually increases from two to eight peaks while their amplitude decreases. In the case of severe wrinkles, the number of peaks stays at four while the amplitude increases dramatically. The intermediate path proves capable of increasing the number of peaks while maintaining a low amplitude. These results will make it possible to design new paths, facilitating the production of defect-free spun parts. Full article
(This article belongs to the Special Issue Advances in Material Forming)
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19 pages, 9884 KiB  
Article
Improving Commercial Motor Bike Rim Disc Hardness Using a Continuous-Wave Infrared Fibre Laser
by Juan Ignacio Ahuir-Torres, Andre D. L. Batako, Nugzar Khidasheli, Nana Bakradze and Guanyu Zhu
J. Manuf. Mater. Process. 2024, 8(1), 18; https://doi.org/10.3390/jmmp8010018 - 24 Jan 2024
Viewed by 1250
Abstract
This study is focused on examining the feasibility of applying laser hardening to a commercial metallic bike rim, employing a CW IR fibre laser. The research comprises two main phases. The first phase involves an assessment of the impact of laser parameters on [...] Read more.
This study is focused on examining the feasibility of applying laser hardening to a commercial metallic bike rim, employing a CW IR fibre laser. The research comprises two main phases. The first phase involves an assessment of the impact of laser parameters on the metallic microstructure, while the second phase involves the actual laser hardening of the bike rim. A comprehensive evaluation encompassing hardness measurements, optical microscopy, and scanning electron microscopy was conducted on the samples. The microstructure type can be manipulated by skilfully adjusting the laser parameters, allowing for the creation of various microstructure variants within the laser-hardened zone for specific laser conditions. In this regard, multiple microstructure types were observed. The hardness of the laser-processed zones exhibited variations corresponding to the specific microstructure. Notably, the molten zone (MZ) and the second heat-affected zone (HAZ II) exhibited the highest levels of hardness. Furthermore, it was observed that a scan overlap of ≥ 75% led to an augmentation in hardness. This study sheds light on the intricate interplay between laser parameters, microstructure, and resultant hardness in the context of laser hardening of metallic materials. Full article
(This article belongs to the Topic Laser Processing of Metallic Materials)
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13 pages, 4994 KiB  
Article
Laser Beam Welding under Vacuum of Hot-Dip Galvanized Constructional Steel
by Christian Frey, Ole Stocks, Simon Olschok, Ronny Kühne, Markus Feldmann and Uwe Reisgen
J. Manuf. Mater. Process. 2024, 8(1), 17; https://doi.org/10.3390/jmmp8010017 - 22 Jan 2024
Viewed by 1423
Abstract
Hot-dip galvanized components offer a great potential for corrosion protection of up to 100 years, while laser beam welding in vacuum (LaVa) has the advantage of high penetration depths Combined, this process chain can be economically used in steel construction of bridges, wind [...] Read more.
Hot-dip galvanized components offer a great potential for corrosion protection of up to 100 years, while laser beam welding in vacuum (LaVa) has the advantage of high penetration depths Combined, this process chain can be economically used in steel construction of bridges, wind turbines, or other steel constructions. Therefore, investigations of butt joint welding of galvanized 20 mm thick S355M steel plates using LaVa were carried out. The butt joints were prepared under different cutting edges such as flame-cut, sawn, and milled edges, and they were studied with and without the zinc layer in the joint gap. For this purpose, the laser parameters such as the beam power, welding speed, focus position, and working pressure all varied, as did the oscillation parameters. The welds performed using an infinity oscillation with an amplitude of 5 mm represented a pore-free weld up to a zinc layer thickness of 400 µm in the joint gap. The seam undercut increased with increasing the zinc layer thickness in the joint gap, which can be explained by the evaporating zinc and consequently the missing material, since no filler material was used. The joint welds with zinc only on the sheet surface achieved a sufficient weld quality without pores. Full article
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14 pages, 10164 KiB  
Article
Prediction of Compressive Behavior of Laser-Powder-Bed Fusion-Processed TPMS Lattices by Regression Analysis
by Uğur Şimşek, Orhan Gülcan, Kadir Günaydın and Aykut Tamer
J. Manuf. Mater. Process. 2024, 8(1), 16; https://doi.org/10.3390/jmmp8010016 - 21 Jan 2024
Viewed by 1586
Abstract
Triply periodic minimal surface (TPMS) structures offer lightweight and high-stiffness solutions to different industrial applications. However, testing of these structures to calculate their mechanical properties is expensive. Therefore, it is important to predict the mechanical properties of these structures effectively. This study focuses [...] Read more.
Triply periodic minimal surface (TPMS) structures offer lightweight and high-stiffness solutions to different industrial applications. However, testing of these structures to calculate their mechanical properties is expensive. Therefore, it is important to predict the mechanical properties of these structures effectively. This study focuses on the effectiveness of using regression analysis and equations based on experimental results to predict the mechanical properties of diamond, gyroid, and primitive TPMS structures with different volume fractions and build orientations. Gyroid, diamond, and primitive specimens with three different volume fractions (0.2, 0.3, and 0.4) were manufactured using a laser powder bed fusion (LPBF) additive manufacturing process using three different build orientations (45°, 60°, and 90°) in the present study. Experimental and statistical results revealed that regression analysis and related equations can be used to predict the mass, yield stress, elastic modulus, specific energy absorption, and onset of densification values of TPMS structures with an intermediate volume fraction value and specified build orientation with an error range less than 1.4%, 7.1%, 19.04%, 21.6%, and 13.4%, respectively. Full article
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25 pages, 1475 KiB  
Article
Implications from Legacy Device Environments on the Conceptional Design of Machine Learning Models in Manufacturing
by Bastian Engelmann, Anna-Maria Schmitt, Lukas Theilacker and Jan Schmitt
J. Manuf. Mater. Process. 2024, 8(1), 15; https://doi.org/10.3390/jmmp8010015 - 17 Jan 2024
Viewed by 1370
Abstract
While new production areas (greenfields) have state-of-the-art technologies for implementing digitalization, existing production areas (brownfields) and devices must first be upgraded with technologies before digitalization can be implemented. The aim of this research work is to use a case study to identify the [...] Read more.
While new production areas (greenfields) have state-of-the-art technologies for implementing digitalization, existing production areas (brownfields) and devices must first be upgraded with technologies before digitalization can be implemented. The aim of this research work is to use a case study to identify the differences in the implementation of machine learning (ML) projects in brownfields and greenfields. For this purpose, an ML application for the detection of changeover times on milling machines is implemented and analyzed in the brownfield and greenfield scenarios as well as a combined scenario. Particular attention is paid to the selection of sensors and features. It was found that the abundant availability of features in the greenfield scenario poses pitfalls when creating ML projects if the underlying sensors cannot be checked for their suitability. For the changeover detector use case, the best model quality was achieved for the combined scenario, followed by the greenfield scenario. Full article
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26 pages, 3809 KiB  
Review
Advancements in Metal Additive Manufacturing: A Comprehensive Review of Material Extrusion with Highly Filled Polymers
by Mahrukh Sadaf, Mario Bragaglia, Lidija Slemenik Perše and Francesca Nanni
J. Manuf. Mater. Process. 2024, 8(1), 14; https://doi.org/10.3390/jmmp8010014 - 16 Jan 2024
Cited by 3 | Viewed by 2293
Abstract
Additive manufacturing (AM) has attracted huge attention for manufacturing metals, ceramics, highly filled composites, or virgin polymers. Of all the AM methods, material extrusion (MEX) stands out as one of the most widely employed AM methods on a global scale, specifically when dealing [...] Read more.
Additive manufacturing (AM) has attracted huge attention for manufacturing metals, ceramics, highly filled composites, or virgin polymers. Of all the AM methods, material extrusion (MEX) stands out as one of the most widely employed AM methods on a global scale, specifically when dealing with thermoplastic polymers and composites, as this technique requires a very low initial investment and usage simplicity. This review extensively addresses the latest advancements in the field of MEX of feedstock made of polymers highly filled with metal particles. After developing a 3D model, the polymeric binder is removed from the 3D-printed component in a process called debinding. Furthermore, sintering is conducted at a temperature below the melting temperature of the metallic powder to obtain the fully densified solid component. The stages of MEX-based processing, which comprise the choice of powder, development of binder system, compounding, 3D printing, and post-treatment, i.e., debinding and sintering, are discussed. It is shown that both 3D printing and post-processing parameters are interconnected and interdependent factors, concurring in determining the resulting mechanical properties of the sintered metal. In particular, the polymeric binder, along with its removal, results to be one of the most critical factors in the success of the entire process. The mechanical properties of sintered components produced through MEX are generally inferior, compared with traditional techniques, as final MEX products are more porous. Full article
(This article belongs to the Topic Additive Manufacturing of Architected Metallic Materials)
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23 pages, 10615 KiB  
Article
Numerical Modeling of Cutting Characteristics during Short Hole Drilling: Part 2—Modeling of Thermal Characteristics
by Michael Storchak, Thomas Stehle and Hans-Christian Möhring
J. Manuf. Mater. Process. 2024, 8(1), 13; https://doi.org/10.3390/jmmp8010013 - 13 Jan 2024
Viewed by 1346
Abstract
The modeling of machining process characteristics and, in particular, of various cutting processes occupies a significant part of modern research. Determining the thermal characteristics in short hole drilling processes by numerical simulation is the object of the present study. For different contact conditions [...] Read more.
The modeling of machining process characteristics and, in particular, of various cutting processes occupies a significant part of modern research. Determining the thermal characteristics in short hole drilling processes by numerical simulation is the object of the present study. For different contact conditions of the workpiece with the drill cutting inserts, the thermal properties of the machined material were determined. The above-mentioned properties and parameters of the model components were established using a three-dimensional finite element model of orthogonal cutting. Determination of the generalized values of the machined material thermal properties was performed by finding the set intersection of individual properties values using a previously developed software algorithm. A comparison of experimental and simulated values of cutting temperature in the workpiece points located at different distances from the drilled hole surface and on the lateral clearance face of the drill outer cutting insert shows the validity of the developed numerical model for drilling short holes. The difference between simulated and measured temperature values did not exceed 22.4% in the whole range of the studied cutting modes. Full article
(This article belongs to the Special Issue Advances in High-Performance Machining Operations)
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