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J. Manuf. Mater. Process., Volume 7, Issue 1 (February 2023) – 50 articles

Cover Story (view full-size image): The Wire and Arc Additive Manufacturing (WAAM) process has a high potential for industrial applications in aviation. This study presents an approach to determine absolute values of the interlayer temperatures during the process using Ti-6Al-4V. The emissivity and transmittance are calibrated to enable a precise thermographic measurement. The methodology is validated by comparing the recorded data with signals from the thermocouples to align the absolute temperature values. Results show that with an interlayer temperature of 200 °C, heat accumulation occurs at the center of the layer due to faster cooling at the free ends. The methodology enables a non-tactile and reproducible measurement of the interlayer temperature during the WAAM process. View this paper
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12 pages, 5689 KiB  
Article
Real-Time Cutting Temperature Measurement in Turning of AISI 1045 Steel through an Embedded Thermocouple—A Comparative Study with Infrared Thermography
by Bruno Guimarães, José Rosas, Cristina M. Fernandes, Daniel Figueiredo, Hernâni Lopes, Olga C. Paiva, Filipe S. Silva and Georgina Miranda
J. Manuf. Mater. Process. 2023, 7(1), 50; https://doi.org/10.3390/jmmp7010050 - 15 Feb 2023
Cited by 7 | Viewed by 2975
Abstract
During machining processes, a high temperature is generated in the cutting zone due to deformation of the material and friction of the chip along the surface of the tool. This high temperature has a detrimental effect on the cutting tool, and for this [...] Read more.
During machining processes, a high temperature is generated in the cutting zone due to deformation of the material and friction of the chip along the surface of the tool. This high temperature has a detrimental effect on the cutting tool, and for this reason, it is of the utmost importance to assess the cutting temperature in real time during these processes. Despite all the advances and investigation in this field, accurately measuring the cutting temperature remains a great challenge. In this sense, this work intends to contribute to solving this problem by experimentally evaluating the potential of the developed approach for embedding thermocouples into the rake face of cutting tools for measuring cutting temperature in real time during dry turning of AISI 1045 steel for different cutting parameters and comparing the obtained results with infrared thermography measurements at the exact same point. A well-defined, smooth micro-groove with good surface quality was produced by laser surface modification. Then a laser-welded K-type thermocouple was fixated in the micro-groove with a MgO ceramic adhesive, ensuring protection from wear and chips, which allowed the creation of WC-Co cutting inserts with the ability to measure cutting tool temperature with a maximum error of 0.96%. Results showed that, despite yielding the same trend, the tool temperature measured by the IR thermographic camera was always lower than the temperature measured by the K-type embedded thermocouple. The proposed embedded thermocouple method proved to be a reliable, precise, accurate, and cost-effective approach for real-time temperature measurement capable of providing useful information for cutting parameter optimization, thus allowing increased productivity and tool life. Full article
(This article belongs to the Special Issue Advances in Metal Cutting and Cutting Tools)
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22 pages, 11634 KiB  
Article
Study on Elucidation of the Roundness Improvement Mechanism of the Internal Magnetic Abrasive Finishing Process Using a Magnetic Machining Tool
by Jiangnan Liu and Yanhua Zou
J. Manuf. Mater. Process. 2023, 7(1), 49; https://doi.org/10.3390/jmmp7010049 - 13 Feb 2023
Cited by 3 | Viewed by 1783
Abstract
The magnetic abrasive finishing process using the magnetic machining tool was proposed to finish the internal surface of the thick tube (the thickness of the tube is 5~30 mm). It has been proved that this process can improve the roundness while improving the [...] Read more.
The magnetic abrasive finishing process using the magnetic machining tool was proposed to finish the internal surface of the thick tube (the thickness of the tube is 5~30 mm). It has been proved that this process can improve the roundness while improving the roughness. In this paper, we mainly study the machining mechanism of roundness improvement. Firstly, the influence of finishing characteristics on the roundness improvement was discussed, including the rotational speed of the magnetic machining tool and the rotational speed of the tube. It was concluded that the roundness improvement increases with the increase in the rotational speed through the analysis of finishing force and finishing times. Furthermore, the influence on roundness improvement of different distributions of magnetic particles were experimentally compared. After finishing, due to the magnetic force generated by the magnetic machining tool and the magnetic pole unit exerting pressure on the magnetic particles, a fixed magnetic brush is formed. The experimental results show that the circumferential length of the fixed magnetic brush is different due to the different distribution areas of magnetic particles. It was concluded that the roundness improvement increases with the circumferential length of the fixed magnetic brush increases by discussing the relationship between the circumferential length of the fixed magnetic brush and the wavelength of the roundness curve. When the circumferential length of the fixed magnetic brush is 76 mm, the roundness was improved from 379 μm to 236 μm after 60 min of finishing. Full article
(This article belongs to the Special Issue Advances in Metal Cutting and Cutting Tools)
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16 pages, 13839 KiB  
Article
Development of a Computationally Efficient Model of the Heating Phase in Thermoforming Process Based on the Experimental Radiation Pattern of Heaters
by Hadi Hosseinionari, Milad Ramezankhani, Rudolf Seethaler and Abbas S. Milani
J. Manuf. Mater. Process. 2023, 7(1), 48; https://doi.org/10.3390/jmmp7010048 - 10 Feb 2023
Cited by 2 | Viewed by 1886
Abstract
In this study, an accurate and computationally efficient model for the heating process of thin thermoplastic sheets during thermoforming is developed. This model opens the door to efficient training of model-free control approaches in thermoforming applications, which often require extensive training data that [...] Read more.
In this study, an accurate and computationally efficient model for the heating process of thin thermoplastic sheets during thermoforming is developed. This model opens the door to efficient training of model-free control approaches in thermoforming applications, which often require extensive training data that would be significantly costly and time-consuming to generate using physical setups. This model takes into account heat transfer via radiation between heaters and the sheet, heat transfer via conduction through the sheet, and heat transfer via convection between the sheet and the ambient. In this paper, rather than using an analytical relationship for the view factor, an experiment is designed to determine the exact radiation pattern of the heater on the sheet and the fraction of infrared emission absorbed by the sheet. Comparing the output temperature profile on the sheet from the designed model to IR images from a laboratory-scale heating system indicates that the mean square error is reduced by around four times when compared to traditional models with analytical view factors. Moreover, a comparison of the computation time with COMSOL software for a scenario with the same configuration of computation hardware reveals that the designed model is almost ten times faster. Full article
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2 pages, 185 KiB  
Editorial
Metal Additive Manufacturing and Its Post-Processing Techniques
by Hao Wang and Jerry Ying Hsi Fuh
J. Manuf. Mater. Process. 2023, 7(1), 47; https://doi.org/10.3390/jmmp7010047 - 10 Feb 2023
Cited by 2 | Viewed by 2579
Abstract
Metal additive manufacturing has made substantial progress in the advanced manufacturing sector with competitive advantages for the efficient production of high-quality products [...] Full article
(This article belongs to the Special Issue Metal Additive Manufacturing and Its Post Processing Techniques)
19 pages, 16807 KiB  
Article
Using 3D Density-Gradient Vectors in Evolutionary Topology Optimization to Find the Build Direction for Additive Manufacturing
by Dylan Bender and Ahmad Barari
J. Manuf. Mater. Process. 2023, 7(1), 46; https://doi.org/10.3390/jmmp7010046 - 9 Feb 2023
Cited by 2 | Viewed by 1884
Abstract
Given its layer-based nature, additive manufacturing is known as a family of highly capable processes for fabricating complex 3D geometries designed by means of evolutionary topology optimization. However, the required support structures for the overhanging features of these complex geometries can be concerningly [...] Read more.
Given its layer-based nature, additive manufacturing is known as a family of highly capable processes for fabricating complex 3D geometries designed by means of evolutionary topology optimization. However, the required support structures for the overhanging features of these complex geometries can be concerningly wasteful. This article presents an approach for studying the manufacturability of the topology-optimized complex 3D parts required for additive manufacturing and finding the optimum corresponding build direction for the fabrication process. The developed methodology uses the density gradient of the design matrix created during the evolutionary topology optimization of the 3D domains to determine the optimal build orientation for additive manufacturing with the objective of minimizing the need for support structures. Highly satisfactory results are obtained by implementing the developed methodology in analytical and experimental studies, which demonstrate potential additive manufacturing mass savings of 170% of the structure’s weight. The developed methodology can be readily used in a variety of evolutionary topology optimization algorithms to design complex 3D geometries for additive manufacturing technologies with a minimized level of waste due to reducing the need for support structures. Full article
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24 pages, 2140 KiB  
Review
A Review on Wire-Fed Directed Energy Deposition Based Metal Additive Manufacturing
by Tuğrul Özel, Hamed Shokri and Raphaël Loizeau
J. Manuf. Mater. Process. 2023, 7(1), 45; https://doi.org/10.3390/jmmp7010045 - 8 Feb 2023
Cited by 12 | Viewed by 6336
Abstract
Metal additive manufacturing has reached a level where products and components can be directly fabricated for applications requiring small batches and customized designs, from tinny body implants to long pedestrian bridges over rivers. Wire-fed directed energy deposition based additive manufacturing enables fabricating large [...] Read more.
Metal additive manufacturing has reached a level where products and components can be directly fabricated for applications requiring small batches and customized designs, from tinny body implants to long pedestrian bridges over rivers. Wire-fed directed energy deposition based additive manufacturing enables fabricating large parts in a cost-effective way. However, achieving reliable mechanical properties, desired structural integrity, and homogeneity in microstructure and grain size is challenging due to layerwise-built characteristics. Manufacturing processes, alloy composition, process variables, and post-processing of the fabricated part strongly affect the resultant microstructure and, as a consequence, component serviceability. This paper reviews the advances in wire-fed directed energy deposition, specifically wire arc metal additive processes, and the recent efforts in grain tailoring during the process for the desired size and shape. The paper also addresses modeling methods that can improve the qualification of fabricated parts by modifying the microstructure and avoid repetitive trials and material waste. Full article
(This article belongs to the Special Issue Editorial Board Members’ Collection Series: Additive Manufacturing)
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23 pages, 8556 KiB  
Article
Influence of Ambient Temperature and Crystalline Structure on Fracture Toughness and Production of Thermoplastic by Enclosure FDM 3D Printer
by Supaphorn Thumsorn, Wattanachai Prasong, Akira Ishigami, Takashi Kurose, Yutaka Kobayashi and Hiroshi Ito
J. Manuf. Mater. Process. 2023, 7(1), 44; https://doi.org/10.3390/jmmp7010044 - 8 Feb 2023
Cited by 7 | Viewed by 2898
Abstract
Fused deposition modeling (FDM) 3D printing has printed thermoplastic materials layer-by-layer to form three dimensional products whereby interlayer adhesion must be well controlled to obtain high mechanical performance and product integrity. This research studied the effects of ambient temperatures and crystalline structure on [...] Read more.
Fused deposition modeling (FDM) 3D printing has printed thermoplastic materials layer-by-layer to form three dimensional products whereby interlayer adhesion must be well controlled to obtain high mechanical performance and product integrity. This research studied the effects of ambient temperatures and crystalline structure on the interlayer adhesion and properties of thermoplastic FDM 3D printing. Five kinds of poly(lactic acid) (PLA) filaments, both commercially available and the laboratory-made, were printed using the enclosure FDM 3D printer. The ambient temperatures were set by the temperature-controlled chamber from room temperature to 75 °C with and without a cooling fan. The interlayer adhesion was characterized by the degree of entanglement density, morphology, and fracture toughness. In addition, PLA filament with high crystallinity has induced heat resistance, which could prevent filament clogging and successfully print at higher chamber temperatures. The ambient temperature increased with increased chamber temperature and significantly increased when printed without a cooling fan, resulting in improved interlayer bonding. The crystalline structure and dynamic mechanical properties of the 3D printed products were promoted when the chamber temperature was increased without a cooling fan, especially in PLA composites and PLA containing a high content of L-isomer. However, although the additives in the PLA composite improved crystallinity and the degree of entanglement density in the 3D-printed products, they induced an anisotropic characteristic that resulted in the declination of the interlayer bonding in the transverse orientation products. The increasing of chamber temperatures over 40 °C improved the interlayer bonding in pristine PLA products, which was informed by the increased fracture toughness. Further, it can be noted that the amorphous nature of PLA promotes molecular entanglement, especially when printed at higher chamber temperatures with and without a cooling fan. Full article
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16 pages, 2037 KiB  
Article
Building Orientation and Post Processing of Ti6Al4V Produced by Laser Powder Bed Fusion Process
by Rosaria Rovetta, Paola Ginestra, Rosalba Monica Ferraro, Keren Zohar-Hauber, Silvia Giliani and Elisabetta Ceretti
J. Manuf. Mater. Process. 2023, 7(1), 43; https://doi.org/10.3390/jmmp7010043 - 7 Feb 2023
Cited by 5 | Viewed by 2162
Abstract
Laser powder bed fusion, particularly the selective laser melting (SLM), is an additive manufacturing (AM) technology used to produce near-net-shaped engineering components for biomedical applications, especially in orthopaedics. Ti6Al4V is commonly used for producing orthopaedic implants using SLM because it has excellent mechanical [...] Read more.
Laser powder bed fusion, particularly the selective laser melting (SLM), is an additive manufacturing (AM) technology used to produce near-net-shaped engineering components for biomedical applications, especially in orthopaedics. Ti6Al4V is commonly used for producing orthopaedic implants using SLM because it has excellent mechanical qualities, a high level of biocompatibility, and corrosion resistance. However, the main problems associated with this process are the result of its surface properties: it has to be able to promote cell attachment but, at the same time, avoid bacteria colonization. Surface modification is used as a post-processing technique to provide items the unique qualities that can improve their functionality and performance in particular working conditions. The goal of this work was to produce and analyse Ti6Al4V samples fabricated by SLM with different building directions in relation to the building plate (0° and 45°) and post-processed by anodization and passivation. The results demonstrate how the production and post processes had an impact on osteoblast attachment, mineralization, and osseointegration over an extended period of time. Though the anodization treatment result was cytotoxic, the biocompatibility of as-built specimens and specimens after passivation treatment was confirmed. In addition, it was discovered that effective post-processing increases the mineralization of these types of 3D-printed surfaces. Full article
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14 pages, 8134 KiB  
Article
Investigation of the Pull-Out Behaviour of Metal Threaded Inserts in Thermoplastic Fused-Layer Modelling (FLM) Components
by Tobias Kastner, Juliane Troschitz, Christian Vogel, Thomas Behnisch, Maik Gude and Niels Modler
J. Manuf. Mater. Process. 2023, 7(1), 42; https://doi.org/10.3390/jmmp7010042 - 7 Feb 2023
Cited by 2 | Viewed by 2036
Abstract
To provide detachable, secure and long-term stable joints in fused-layer modelling (FLM) components or assemblies, metal threaded inserts are widely used as extrinsic interfaces. However, the load-bearing capacity of such inserts is influenced by the inhomogeneous, anisotropic material structure of the FLM components. [...] Read more.
To provide detachable, secure and long-term stable joints in fused-layer modelling (FLM) components or assemblies, metal threaded inserts are widely used as extrinsic interfaces. However, the load-bearing capacity of such inserts is influenced by the inhomogeneous, anisotropic material structure of the FLM components. This work evaluates the influence of the joining zone design and the printing process parameters on the achievable joint properties. Therefore, we printed thermoplastic FLM test specimens with varying parameters for infill density, wall thickness, layer height and nozzle temperature. Subsequently, metal threaded inserts were warm-embedded into the test specimens and investigated in quasi-static pull-out tests. The results show that the infill density in the joining zone has the largest impact on the joint strength and should be 70% or higher. Furthermore, an analysis of different wall thicknesses around the pre hole shows that a minimum value of 2.4 mm is required for the selected insert geometry to achieve a high pull-out force. Increasing the wall thickness beyond this value does not significantly affect the joint strength. The results provide an improved base for detailed understanding and interface design in FLM components for the integration of metal threaded inserts as well as for further investigations regarding different printing materials and load types. Full article
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29 pages, 7556 KiB  
Article
Development and Practical Implementation of Digital Observer for Elastic Torque of Rolling Mill Electromechanical System
by Vadim R. Gasiyarov, Andrey A. Radionov, Boris M. Loginov, Alexander S. Karandaev, Olga A. Gasiyarova and Vadim R. Khramshin
J. Manuf. Mater. Process. 2023, 7(1), 41; https://doi.org/10.3390/jmmp7010041 - 4 Feb 2023
Cited by 10 | Viewed by 1812
Abstract
The strategic initiative aimed at building “digital metallurgy” implies the introduction of diagnostic monitoring systems to trace the technical condition of critical production units. This problem is relevant for rolling mills, which provide the output and determine the quality of products of metallurgical [...] Read more.
The strategic initiative aimed at building “digital metallurgy” implies the introduction of diagnostic monitoring systems to trace the technical condition of critical production units. This problem is relevant for rolling mills, which provide the output and determine the quality of products of metallurgical companies. Making up monitoring systems requires the development of digital shadows and coordinate observers, the direct measurement of which is either impossible or associated with numerous difficulties. These coordinates include the spindle torque applied by the spring-transmitting torque from the motor to the rolling stand rolls. The development and research are conducted by the example of the electromechanical systems of the horizontal stand at the plate mill 5000. The stand electric drive characteristics are given, and the emergency modes that cause mechanical equipment breakdowns are analyzed that. The relevance of analyzing transient torque processes in emergency modes has been accentuated. The paper points to the shortcomings of the system for elastic torque direct measurement, including low durability due to the harsh operating conditions of precision sensors. It also highlights the need to install the measuring equipment after each spindle. The disadvantage of the previously developed observer is the function of calculating the electric drive speed derivative. This causes a decrease in noise immunity and signal recovery accuracy. The contribution of this paper is building a digital elastic torque observer that has advantages over conventional technical solutions, based on the theoretical and experimental studies. The technique for virtual observer adjustment was developed and tested in the Matlab-Simulink software package. For the first time, a comprehensive analysis was conducted for spindle elastic torques in emergency modes that caused equipment damage. An algorithm was developed for an emergency shutdown of a stand electric drive in the worst-case mode of strip retraction between work and backup rolls, due to the overlap of the strip on the roll. Further, the algorithm was tested experimentally. The criteria for diagnosing pre-emergencies was then justified. An adaptive motor-braking rate controller was developed. The developed observer and emergency braking system are in operation at the mill 5000. Long experimental research proved the efficiency of dynamic load monitoring and the reduction in the number of equipment breakdowns. Full article
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18 pages, 6843 KiB  
Article
Investigation of Pressure Fields Generated by Two Simultaneous Discharges in Liquid Initiated by Wires
by Mykhaylo Knyazyev, Maik Holzmüller and Werner Homberg
J. Manuf. Mater. Process. 2023, 7(1), 40; https://doi.org/10.3390/jmmp7010040 - 2 Feb 2023
Cited by 2 | Viewed by 1440
Abstract
The pressure fields generated by two simultaneous discharges have not been investigated on any notable scale for the electrohydraulic impulse forming method. In this study, the synchronicity of two discharges is ensured by the sequential connection of two wires mounted in two spark [...] Read more.
The pressure fields generated by two simultaneous discharges have not been investigated on any notable scale for the electrohydraulic impulse forming method. In this study, the synchronicity of two discharges is ensured by the sequential connection of two wires mounted in two spark gaps in a common volume of liquid. The objective is to experimentally confirm the equilibrium of the energies evolved in two spark gaps by means of pressure measurements. In addition, multipoint membrane pressure gauges demonstrated the feasibility of easily recording detailed pressure maps. Based on the membrane deformation mechanism and material strengthening under static and impulse conditions, the processing procedure is further developed so as to achieve better accuracy in the determination of pressure field parameters. The practical equality of the pressure fields on the left and right halves of the flat-loaded area confirms the equality of energies evolved in the two spark gaps. The direct shock waves create zones with the most intensive loading. These results provide a basis for the development of new electrohydraulic technologies involving the application of two simultaneous discharges with equal energy and pressure parameters. Full article
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16 pages, 3894 KiB  
Article
Investigation of Welding Parameters of Dissimilar Weld of SS316 and ASTM A36 Joint Using a Grey-Based Taguchi Optimization Approach
by Diah Kusuma Pratiwi, Amir Arifin, Gunawan, Alim Mardhi and Afriansyah
J. Manuf. Mater. Process. 2023, 7(1), 39; https://doi.org/10.3390/jmmp7010039 - 2 Feb 2023
Cited by 13 | Viewed by 2668
Abstract
A grey-based Taguchi method was applied to investigate the optimal operating conditions in shielded metal arc welding (SMAW) to join SS316 and ASTM A36. This work aims to set optimal parameters for the mechanical properties of the weld joint. The effects of various [...] Read more.
A grey-based Taguchi method was applied to investigate the optimal operating conditions in shielded metal arc welding (SMAW) to join SS316 and ASTM A36. This work aims to set optimal parameters for the mechanical properties of the weld joint. The effects of various welding factors on electrode type, welding current, arc welding, and welding speed have to be characterized and optimized to achieve an optimum condition. An L9 orthogonal array was used to group the various components. The mechanical properties of a dissimilar weld joints were described through hardness, tensile and flexural strength tests. The optimum welding parameters were obtained simultaneously as an electrode type E309, a welding current of 100 A, an arc voltage of 14 V, and a welding speed of 4 cm/min, which predicted improve 23.0% in its performance. Full article
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25 pages, 14776 KiB  
Article
Mechanical Performance over Energy Expenditure in MEX 3D Printing of Polycarbonate: A Multiparametric Optimization with the Aid of Robust Experimental Design
by Nectarios Vidakis, Markos Petousis, Constantine N. David, Dimitrios Sagris, Nikolaos Mountakis and Emmanuel Karapidakis
J. Manuf. Mater. Process. 2023, 7(1), 38; https://doi.org/10.3390/jmmp7010038 - 1 Feb 2023
Cited by 14 | Viewed by 1631
Abstract
Sustainability and energy efficiency of additive manufacturing (AM) is an up-to-date industrial request. Likewise, the claim for 3D-printed parts with capable mechanical strength remains robust, especially for polymers that are considered high-performance ones, such as polycarbonates in material extrusion (MEX). This paper explains [...] Read more.
Sustainability and energy efficiency of additive manufacturing (AM) is an up-to-date industrial request. Likewise, the claim for 3D-printed parts with capable mechanical strength remains robust, especially for polymers that are considered high-performance ones, such as polycarbonates in material extrusion (MEX). This paper explains the impact of seven generic control parameters (raster deposition angle; orientation angle; layer thickness; infill density; nozzle temperature; bed temperature; and printing speed) on the energy consumption and compressive performance of PC in MEX AM. To meet this goal, a three-level L27 Taguchi experimental design was exploited. Each experimental run included five replicas (compressive specimens after the ASTM D695-02a standard), summating 135 experiments. The printing time and the power consumption were stopwatch-derived, whereas the compressive metrics were obtained by compressive tests. Layer thickness and infill density were ranked the first and second most significant factors in energy consumption. Additionally, the infill density and the orientation angle were proved as the most influential factors on the compressive strength. Lastly, quadratic regression model (QRM) equations for each response metric versus the seven control parameters were determined and evaluated. Hereby, the optimum compromise between energy efficiency and compressive strength is attainable, a tool holding excessive scientific and engineering worth. Full article
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23 pages, 86090 KiB  
Article
Load Introduction Specimen Design for the Mechanical Characterisation of Lattice Structures under Tensile Loading
by Justin Jung, Guillaume Meyer, Matthias Greiner and Christian Mittelstedt
J. Manuf. Mater. Process. 2023, 7(1), 37; https://doi.org/10.3390/jmmp7010037 - 1 Feb 2023
Cited by 3 | Viewed by 2383
Abstract
In recent years, it has been demonstrated that the lightweight potential of load-carrying structural components could be further enhanced using additive manufacturing technology. However, the additive manufacturing process offers a large parameter space that highly impacts the part quality and their inherent mechanical [...] Read more.
In recent years, it has been demonstrated that the lightweight potential of load-carrying structural components could be further enhanced using additive manufacturing technology. However, the additive manufacturing process offers a large parameter space that highly impacts the part quality and their inherent mechanical properties. Therefore, the most influential parameters need to be identified separately, categorised, classified and incorporated into the design process. To achieve this, the reliable testing of mechanical properties is crucial. The current developments concerning additively manufactured lattice structures lack unified standards for tensile testing and specimen design. A key factor is the high stress concentrations at the transition between the lattice structure and the solid tensile specimen’s clamping region. The present work aims to design a topology-optimised transition region applicable to all cubic unit cell types that avoids high samples potentially involved in structural grading. On the basis of fulfilling the defined objective and satisfying the constraints of the stress and uniaxiality conditions, the most influential parameters are identified through a correlation analysis. The selected design solutions are further analysed and compared to generic transition design approaches. The most promising design features (compliant edges, rounded cross-section, pillar connection) are then interpreted into structural elements, leading to an innovative generic design of the load introduction region that yields promising results after a proof-of-concept study. Full article
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19 pages, 7335 KiB  
Article
Influence of Deposition Parameters on Hardness Properties of InconelTM 718 Processed by Laser Powder Bed Fusion for Space Applications
by Raffaella Sesana, Cristiana Delprete, Marco Pizzarelli, Matteo Crachi, Luca Lavagna, Domenico Borrelli and Antonio Caraviello
J. Manuf. Mater. Process. 2023, 7(1), 36; https://doi.org/10.3390/jmmp7010036 - 1 Feb 2023
Viewed by 1968
Abstract
InconelTM 718 is widely used for commercial application in aerospace industry and additive manufacturing process allows for versatile design and manufacturing opportunities. In the present research, the results of a wide experimental campaign run on additive manufactured InconelTM 718 specimens obtained [...] Read more.
InconelTM 718 is widely used for commercial application in aerospace industry and additive manufacturing process allows for versatile design and manufacturing opportunities. In the present research, the results of a wide experimental campaign run on additive manufactured InconelTM 718 specimens obtained with different processing parameters are presented. In particular, the influence of process parameters (for both vertical and horizontal planes with respect to the building direction) on the hardness properties are investigated. A further investigation is performed on the optimal hardness testing procedure for additive manufacturing. The research is extended to as-built and heat-treated specimens. The new insight gained is that the orientation of the printing direction with respect to indentation direction can be responsible for scattering in hardness measurements and indentation size effect. As-built specimens show a strong anisotropy for in-plane and growth directions and an increment of hardness with respect to increasing energy density. The difference between hardness value with respect to the energy density and the measurements scattering are reduced by the heat treatment. A careful handling of hardness data is required when dealing with additive manufactured materials. Full article
(This article belongs to the Special Issue Precision Additive Manufacturing Processes)
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42 pages, 11001 KiB  
Review
Liquid-Based 4D Printing of Shape Memory Nanocomposites: A Review
by Mohamad Alsaadi, Eoin P. Hinchy, Conor T. McCarthy, Vicente F. Moritz, Shuo Zhuo, Evert Fuenmayor and Declan M. Devine
J. Manuf. Mater. Process. 2023, 7(1), 35; https://doi.org/10.3390/jmmp7010035 - 31 Jan 2023
Cited by 12 | Viewed by 4687
Abstract
Significant advances have been made in recent years in the materials development of liquid-based 4D printing. Nevertheless, employing additive materials such as nanoparticles for enhancing printability and shape memory characteristics is still challenging. Herein, we provide an overview of recent developments in liquid-based [...] Read more.
Significant advances have been made in recent years in the materials development of liquid-based 4D printing. Nevertheless, employing additive materials such as nanoparticles for enhancing printability and shape memory characteristics is still challenging. Herein, we provide an overview of recent developments in liquid-based 4D printing and highlights of novel 4D-printable polymeric resins and their nanocomposite components. Recent advances in additive manufacturing technologies that utilise liquid resins, such as stereolithography, digital light processing, material jetting and direct ink writing, are considered in this review. The effects of nanoparticle inclusion within liquid-based resins on the shape memory and mechanical characteristics of 3D-printed nanocomposite components are comprehensively discussed. Employing various filler-modified mixture resins, such as nanosilica, nanoclay and nanographene, as well as fibrous materials to support various properties of 3D printing components is considered. Overall, this review paper provides an outline of liquid-based 4D-printed nanocomposites in terms of cutting-edge research, including shape memory and mechanical properties. Full article
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16 pages, 6143 KiB  
Article
On Friction, Heat Input, and Material Flow Initiation during Friction Stir Welding: Tool and Process Optimization
by Max Hossfeld
J. Manuf. Mater. Process. 2023, 7(1), 34; https://doi.org/10.3390/jmmp7010034 - 31 Jan 2023
Cited by 4 | Viewed by 2778
Abstract
The Friction Stir Welding (FSW) process depends entirely upon mechanical contact between the tool and the workpiece. As a result of this, all process phenomena and process outcomes such as weld geometry and mechanical properties are governed by FSW’s frictional system. The following [...] Read more.
The Friction Stir Welding (FSW) process depends entirely upon mechanical contact between the tool and the workpiece. As a result of this, all process phenomena and process outcomes such as weld geometry and mechanical properties are governed by FSW’s frictional system. The following work characterizes this system with a focus on process initialization, heat input and material flow. For this purpose, an experimental program for the isolated investigation of the frictional system was carried out. Short-term effects such as contact initiation, run-in behavior and frictional transitions are considered as well as the influences of process parameters and geometry. The system and its behavior are analyzed quantitatively and qualitatively by experiments altering the normal pressure, relative velocity, and tool geometry. The experiments demonstrate a self-similar behavior of the process, including an important wear transition which initiates the material flow, and a subsequent equilibrium of forces, heat balance, and temperatures. The interaction between the tool and the welded material is described, as is the link between the frictional interface and material flow initialization. Based on these findings, recommendations are provided for process optimization and tool design. Full article
(This article belongs to the Special Issue Frontiers in Friction Stir Welding and Processing)
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20 pages, 6330 KiB  
Article
Process-Structure-Property Interdependencies in Non-Isothermal Powder Bed Fusion of Polyamide 12
by Samuel Schlicht, Simon Cholewa and Dietmar Drummer
J. Manuf. Mater. Process. 2023, 7(1), 33; https://doi.org/10.3390/jmmp7010033 - 30 Jan 2023
Cited by 3 | Viewed by 2186
Abstract
Non-isothermal laser-based powder bed fusion (LPBF) of polymers suggests the potential for significantly extending the range of materials applicable for powder-based additive manufacturing of polymers, relying on the absence of a material-specific processing window. To allow for the support-free manufacturing of polymers at [...] Read more.
Non-isothermal laser-based powder bed fusion (LPBF) of polymers suggests the potential for significantly extending the range of materials applicable for powder-based additive manufacturing of polymers, relying on the absence of a material-specific processing window. To allow for the support-free manufacturing of polymers at a build chamber temperature of 25 °C, applied processing strategies comprise the combination of fractal exposure strategies and locally quasi-simultaneous exposure of distinct segments of a particular cross section for minimizing crystallization-induced part deflection. Based on the parameter-dependent control of emerging cooling rates, formed part morphologies and resulting mechanical properties can be modified. Thermographic in situ measurements allow for correlating thermal processing conditions and crystallization kinetics with component-specific mechanical, morphological, and microstructural properties, assessed ex situ. Part morphologies formed at crystallization temperatures below 70 °C, induced by reduced laser exposure times, are characterized by a nano-spherulitic structure, exhibiting an enhanced elongation at break. An ambient temperature of 25 °C is associated with the predominant formation of a combined (α + γ)-phase, induced by the rapid cooling and subsequent laser-induced tempering of distinct layers, yielding a periodic microstructural evolution. The presented results demonstrate a novel approach for obtaining nano-spherulitic morphologies, enabling the exposure-based targeted adaption of morphological properties. Furthermore, the thermographic inline assessment of crystallization kinetics allows for the enhanced understanding of process-morphology interdependencies in laser-based manufacturing processes of semi-crystalline polymers. Full article
(This article belongs to the Special Issue Progress in Powder-Based Additive Manufacturing)
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15 pages, 8944 KiB  
Article
Effect of Heat Treatment on the Mechanical and Tribological Properties of Dual-Reinforced Cold-Sprayed Al Coatings
by Kia Min Phua, Thomas Stapel and Troy Y. Ansell
J. Manuf. Mater. Process. 2023, 7(1), 32; https://doi.org/10.3390/jmmp7010032 - 28 Jan 2023
Cited by 1 | Viewed by 1563
Abstract
The aluminum cold spray feedstock powder was single- and dual-reinforced with no greater than 2 vol% boron nitride nanoplatelets (BNNP) and/or nanometric boron carbide (nB4C). These powders were cold sprayed onto Al-6061 substrates and then heat-treated in an argon environment. In [...] Read more.
The aluminum cold spray feedstock powder was single- and dual-reinforced with no greater than 2 vol% boron nitride nanoplatelets (BNNP) and/or nanometric boron carbide (nB4C). These powders were cold sprayed onto Al-6061 substrates and then heat-treated in an argon environment. In addition, micro- and nano-indentation hardness and wear testing were performed on the heat-treated samples. Further microscopy and optical profilometry were used to characterize the microstructure and wear track volumes. Minimal changes to the splat structure were observed after heat treatment. However, when compared to the pure Al coating, microhardness improved with reinforcement after treatment at 500 °C, while nanohardness improved only in the dual-reinforced coatings, again after treatment at 500 °C. The elastic modulus generally decreased for the reinforced coatings after treatment; however, indentation test results were mixed. The wear testing done on samples heat treated at 500 °C for one hour showed increases in the specific wear rate for single-reinforced coatings but decreases in the dual-reinforced coatings. These results indicate that both dual-reinforcement and heat treatment are required for improvements in the mechanical and tribological properties of Al nanocomposites. Full article
(This article belongs to the Special Issue Advances in Metal Forming and Thermomechanical Processing)
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16 pages, 3245 KiB  
Article
Evaluation of Processing Conditions in the Performance of Purging Compounds for Polypropylene Injection Molding
by Miguel Carrasco, Jorge Guerrero, Miriam Lazo, Estephany Adrián, Jorge Alberto Medina-Perilla and Andrés Rigail-Cedeño
J. Manuf. Mater. Process. 2023, 7(1), 31; https://doi.org/10.3390/jmmp7010031 - 26 Jan 2023
Cited by 2 | Viewed by 2908
Abstract
Purging is a fundamental process in the injection molding sector, aiding in color transition, material shifts, and the removal of contaminants. The purging compounds can be classified according to physical or chemical mechanisms and are affected by processing parameters, such as temperature, pressure, [...] Read more.
Purging is a fundamental process in the injection molding sector, aiding in color transition, material shifts, and the removal of contaminants. The purging compounds can be classified according to physical or chemical mechanisms and are affected by processing parameters, such as temperature, pressure, or soaking period. Despite some studies on the effect of processing parameters in purging action, an analysis of the rheological behavior and physico-chemical changes is still required for a deeper understanding of this type of system. This study explored shear viscosity, activation energy behavior in the torque rheometer, injection molding process, and energy consumption for two polyolefin-based purging compounds: one on polypropylene (PP) and another on polyethylene (PE). The results showed that the PP-based compound is a highly viscous material with low thermal sensibility and low energy consumption. The PE-based chemical compound, which includes an expanding and scrubbing agent, presented higher thermal sensitivity. Lower purging times and specific energy consumption were observed for the mechanical purge regardless of the processing temperature in the injection molding machine. However, torque and specific total mechanical energy differed due to viscosity and possible filler particle agglomeration. These findings demonstrated the influence of processing temperature on rheology and performance. Nonetheless, further studies regarding pressure, soaking time, and rheological modeling are recommended. Full article
(This article belongs to the Special Issue Advances in Injection Molding: Process, Materials and Applications)
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19 pages, 6048 KiB  
Article
Design Optimization of Hot Isostatic Pressing Capsules
by Samaneh Sobhani, Marc Albert, David Gandy, Ali Tabei and Zhaoyan Fan
J. Manuf. Mater. Process. 2023, 7(1), 30; https://doi.org/10.3390/jmmp7010030 - 25 Jan 2023
Cited by 3 | Viewed by 2549
Abstract
Power metallurgy hot isostatic pressing (PM-HIP) is a manufacturing technique capable of producing net shape or near-net shape components with complicated geometries from materials that are difficult to melt and cast, mechanically deform or weld. However, the process and soundness of the outcome [...] Read more.
Power metallurgy hot isostatic pressing (PM-HIP) is a manufacturing technique capable of producing net shape or near-net shape components with complicated geometries from materials that are difficult to melt and cast, mechanically deform or weld. However, the process and soundness of the outcome are extremely sensitive to the geometric design of the capsule (also known as the die or can) that is used in the process. The capsule design for each new component involves several trial–error iterations to achieve the desired geometry and shape of the component. For each iteration, costly HIP experiments need to be conducted and new capsules need be manufactured with small modifications. In this study, a robust finite element analysis (FEA) model of the HIP process is developed, then wrapped in a multi-objective genetic algorithm (MOGA) optimization framework to obtain the optimal pre-HIP capsule design, which yields the desired post-HIP component geometry in one HIP run. The FEA-based optimization algorithm is validated by HIP experiments, showing excellent agreement between the experiment and the model. Full article
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18 pages, 8837 KiB  
Article
The Development of an Assembled Truss Core Lightweight Panel and Its Method of Manufacture
by Zhilei Tian, Chenghai Kong, Jingchao Guan, Wei Zhao, Apollo B. Fukuchi and Xilu Zhao
J. Manuf. Mater. Process. 2023, 7(1), 29; https://doi.org/10.3390/jmmp7010029 - 23 Jan 2023
Viewed by 1541
Abstract
In this study, a new assembled truss core panel and the method for processing it were proposed in order to improve the performance of the lightweight panel structure. The proposed assembled truss core panel can be easily processed by simple punching and bending. [...] Read more.
In this study, a new assembled truss core panel and the method for processing it were proposed in order to improve the performance of the lightweight panel structure. The proposed assembled truss core panel can be easily processed by simple punching and bending. A processing experiment on an assembled truss core panel was conducted using an aluminum plate with a thickness of 1.0 mm, and the validity and performance of the proposed processing method were verified. A three-point bending test was performed using an assembled truss core panel obtained using the processing experiment. The assembled truss core panel had a relatively high bending stiffness in its early elastic deformation and a relatively long-lasting bending deformation after the initial failure. Its application as a lightweight panel has been confirmed. In order to compare it with the most commonly used honeycomb lightweight panel, FEM (finite element method) analysis was performed on the assembled truss core panel and on the honeycomb panel under the same conditions. The bending stiffness of the assembled truss core panel was found to be 10.60% higher than that of the honeycomb panel. Furthermore, to improve the productivity of the assembly-type truss core panel, construction of a production line using progressive dies was proposed, and the possibility of practical development for mass production was examined. Full article
(This article belongs to the Special Issue Design and Additive Manufacturing of Lightweight Composite Structures)
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21 pages, 8614 KiB  
Article
Simulated Study of the Machinability of the Nomex Honeycomb Structure
by Tarik Zarrouk, Mohammed Nouari and Hamid Makich
J. Manuf. Mater. Process. 2023, 7(1), 28; https://doi.org/10.3390/jmmp7010028 - 20 Jan 2023
Cited by 10 | Viewed by 1960
Abstract
The Nomex honeycomb core has been widely used in many industrial fields, especially the aircraft and aerospace industries, due to its high strength and stiffness to heaviness ratio. Machining of the Nomex honeycomb structure is usually associated with tearing of the walls, deformations [...] Read more.
The Nomex honeycomb core has been widely used in many industrial fields, especially the aircraft and aerospace industries, due to its high strength and stiffness to heaviness ratio. Machining of the Nomex honeycomb structure is usually associated with tearing of the walls, deformations of the cells and the appearance of burrs. Therefore, milling of the Nomex honeycomb structure represents an industrial hurdle challenge for scientists and researchers about the quality of the machined surface and the integrity of the cutting tool. In response to this problem, we have developed a three-dimensional numerical model of finite elements based on the real conditions of experimental work by means of the analysis software Abaqus. Based on the developed numerical model, an experimental validation was performed by comparing the quality of the surface and the adhesive wear of the cutting tool determined from the numerical simulation and that established by the experiment. In addition, the effect of geometric parameters in terms of wedge angle and cutting tool diameter on material accumulation, chip size, generated surface and cutting forces was analyzed. The results of the quantitative analysis prove that the choice of cutting conditions and cutting tool geometry in terms of favorable rake angle and tool diameter improves the surface quality of the generated part and optimizes the integrity of the cutting tool. Full article
(This article belongs to the Special Issue Advances in Machining of Difficult-to-Cut Materials)
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5 pages, 163 KiB  
Editorial
Acknowledgment to the Reviewers of JMMP in 2022
by JMMP Editorial Office
J. Manuf. Mater. Process. 2023, 7(1), 27; https://doi.org/10.3390/jmmp7010027 - 19 Jan 2023
Viewed by 988
Abstract
High-quality academic publishing is built on rigorous peer review [...] Full article
15 pages, 5410 KiB  
Article
Introduction of a New Test Methodology for Determining the Delayed Cracking Susceptibility
by Anton Hopf, Moritz Klug, Kürşat Durmaz, Klaus Goth and Sven Jüttner
J. Manuf. Mater. Process. 2023, 7(1), 26; https://doi.org/10.3390/jmmp7010026 - 18 Jan 2023
Cited by 2 | Viewed by 2310
Abstract
A missing test methodology that allows for the determination of delayed cracking susceptibility of laser welds of high-strength sheet steel is presented. Unlike other cold crack testing methods, this test is based on a self-restraint testing of specimens welded from thin sheet materials [...] Read more.
A missing test methodology that allows for the determination of delayed cracking susceptibility of laser welds of high-strength sheet steel is presented. Unlike other cold crack testing methods, this test is based on a self-restraint testing of specimens welded from thin sheet materials without welding consumables and external loading. The potential test procedure with sample geometry, clamping device and documentation of the cracks is described. It is shown that the position of the weld on the specimen is a critical parameter and the susceptibility to cold cracking increases with increasing edge distance. The test methodology in combination with the most critical seam position is successfully used to rank two different steels regarding their susceptibility to delayed cracking. Further investigations are conducted evaluating the cold cracking susceptibility at different energy levels and lubricating conditions. It is proven that the lubrication has a significant influence on the susceptibility to cold cracking. Nevertheless, a narrow but safe process window is found. Full article
(This article belongs to the Special Issue Advances in Welding Technology)
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18 pages, 10358 KiB  
Article
Strain-Based Fatigue Experimental Study on Ti–6Al–4V Alloy Manufactured by Electron Beam Melting
by Alberto David Pertuz-Comas, Octavio Andrés González-Estrada, Elkin Martínez-Díaz, Diego Fernando Villegas-Bermúdez and Jorge Guillermo Díaz-Rodríguez
J. Manuf. Mater. Process. 2023, 7(1), 25; https://doi.org/10.3390/jmmp7010025 - 18 Jan 2023
Cited by 6 | Viewed by 2122
Abstract
Additive manufacturing (AM) by electron beam melting (EBM) is a technique used to manufacture parts by melting powder metal layer-by-layer with an electron beam in a high vacuum, thereby generating a 3D topology. This paper studies the low-cycle fatigue of Ti–6Al–4V specimens obtained [...] Read more.
Additive manufacturing (AM) by electron beam melting (EBM) is a technique used to manufacture parts by melting powder metal layer-by-layer with an electron beam in a high vacuum, thereby generating a 3D topology. This paper studies the low-cycle fatigue of Ti–6Al–4V specimens obtained by EBM. Static tests were carried out according to ASTM E8 for a yield stress of 1023 MPa, a fracture stress of 1102 MPa, and a maximum tensile strength of 1130 MPa with a maximum true normal strain at fracture εmax = 9.0% and an elastic modulus of 120 GPa. Then, fatigue tests were conducted at a load inversion rate of R = −1. It was observed that the material exhibited plastic strain softening, which was attributed to the Bauschinger effect. These results were plotted on a strain vs. life (ε−N) curve using the Ong version of the Coffin–Manson rule and the Baumel–Seager and Meggiolaro–Castro rules. The results were compared to forged Ti–6Al–4V alloys. The cyclic stress–strain behavior was described with the Ramberg–Osgood model. Finally, the fracture surface was analyzed using scanning electron microscopy (SEM) to observe the formation of primary cracks. The fracture morphology showed a mixed surface, also known as a “quasi-cleavage”, which is characterized by dimples, cleavage facets, extensive primary cracks with broken slipping planes, and a large number of inclusions. This phenomenon caused a possible brittle behavior in the material. Full article
(This article belongs to the Special Issue Advances in Metal Additive Manufacturing/3D Printing)
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19 pages, 8075 KiB  
Article
Fundamental Investigations to Evaluate the Influence of Notching Processes on a Subsequent Cyclic Bending Process for the Production of Wire Cores
by Alina Biallas, Sophia Ohmayer and Marion Merklein
J. Manuf. Mater. Process. 2023, 7(1), 24; https://doi.org/10.3390/jmmp7010024 - 17 Jan 2023
Cited by 1 | Viewed by 1677
Abstract
The production of wire cores by notch rolling and cyclic bending promises an ecologically and economically efficient manufacturing option for steel fibers. The paper at hand evaluates the influence of wire strips on cyclic bending by applying rolled wire strips of DP600 sheet [...] Read more.
The production of wire cores by notch rolling and cyclic bending promises an ecologically and economically efficient manufacturing option for steel fibers. The paper at hand evaluates the influence of wire strips on cyclic bending by applying rolled wire strips of DP600 sheet metal (t0 = 0.8 mm) and a new cyclic bending testing tool. Analysis of material separation with varying parameters, rolling gap d and bending angle β, proves the interdependency of both process step, but indicates reduced adjustability of the notch rolling process. To enable better adjustability of the wire strip’s characteristics and analysis of their effects, wire strip production in the laboratory by notch stamping instead of rolling is aspired. The prior interaction analysis states the web height b, the notch angle α, and the hardening distribution as relevant wire strip’s characteristics to be replicated. Based on experimental analysis, an equivalent of notch rolling by notch stamping is deduced by considering the web height b identical for stamping and rolling, by adjusting the tool’s notch angle αt based on an equation considering geometric evaluations of α, and by taking advantage of the asymmetric hardening distribution of the outer notch which is comparable to rolled wire strip. Full article
(This article belongs to the Special Issue Advances in Metal Forming and Thermomechanical Processing)
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16 pages, 10062 KiB  
Article
Modeling of Surface Roughness in Honing Processes by Using Fuzzy Artificial Neural Networks
by Irene Buj-Corral, Piotr Sender and Carmelo J. Luis-Pérez
J. Manuf. Mater. Process. 2023, 7(1), 23; https://doi.org/10.3390/jmmp7010023 - 15 Jan 2023
Cited by 2 | Viewed by 1953
Abstract
Honing processes are abrasive machining processes which are commonly employed to improve the surface of manufactured parts such as hydraulic or combustion engine cylinders. These processes can be employed to obtain a cross-hatched pattern on the internal surfaces of cylinders. In this present [...] Read more.
Honing processes are abrasive machining processes which are commonly employed to improve the surface of manufactured parts such as hydraulic or combustion engine cylinders. These processes can be employed to obtain a cross-hatched pattern on the internal surfaces of cylinders. In this present study, fuzzy artificial neural networks are employed for modeling surface roughness parameters obtained in finishing honing operations. As a general trend, main factors influencing roughness parameters are grain size and pressure. Mean spacing between profile peaks at the mean line parameter, on the contrary, depends mainly on tangential and linear velocity. Grain Size of 30 and pressure of 600 N/cm2 lead to the highest values of core roughness (Rk) and reduced valley depth (Rvk), which were 1.741 µm and 0.884 µm, respectively. On the other hand, the maximum peak-to-valley roughness parameter (Rz) so obtained was 4.44 µm, which is close to the maximum value of 4.47 µm. On the other hand, values of the grain size equal to 14 and density equal to 20, along with pressure 600 N/cm2 and both tangential and linear speed of 20 m/min and 40 m/min, respectively, lead to the minimum values of core roughness, reduced peak height (Rpk), reduced valley depth and maximum peak-to-valley height of the profile within a sampling length, which were, respectively, 0.141 µm, 0.065 µm, 0.142 µm, and 0.584 µm. Full article
(This article belongs to the Special Issue Advances in Precision Machining Processes)
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16 pages, 5192 KiB  
Article
Multi-Response Optimization of Ti6Al4V Support Structures for Laser Powder Bed Fusion Systems
by Antonios Dimopoulos, Ilias Zournatzis, Tat-Hean Gan and Panagiotis Chatzakos
J. Manuf. Mater. Process. 2023, 7(1), 22; https://doi.org/10.3390/jmmp7010022 - 13 Jan 2023
Cited by 6 | Viewed by 2916 | Correction
Abstract
Laser Powder Bed Fusion (LPBF) is one of the most commonly used and rapidly developing metal Additive Manufacturing (AM) technologies for producing optimized geometries, complex features, and lightweight components, in contrast to traditional manufacturing, which limits those characteristics. However, this technology faces difficulties [...] Read more.
Laser Powder Bed Fusion (LPBF) is one of the most commonly used and rapidly developing metal Additive Manufacturing (AM) technologies for producing optimized geometries, complex features, and lightweight components, in contrast to traditional manufacturing, which limits those characteristics. However, this technology faces difficulties with regard to the construction of overhang structures and warping deformation caused by thermal stresses. Producing overhangs without support structures results in collapsed parts, while adding unnecessary supports increases the material required and post-processing. The purpose of this study was to evaluate the various support and process parameters for metal LPBF, and propose optimized support structures to minimize Support Volume, Support Removal Effort, and Warping Deformation. The optimization approach was based on the Design of Experiments (DOE) methodology and multi-response optimization, by 3D printing and studying overhang geometries from 0° to 45°. For this purpose, EOS Titanium Ti64 Grade 5 powder was used, a Ti6Al4V alloy commonly employed in LPBF. For 0° overhangs, the optimum solution was characterized by an average Tooth Height, large Tooth Top Length, low X, Y Hatching, and high Laser Speed, while for 22.5° and 45° overhangs, it was characterized by large Tooth Height, low Tooth Top Length, high X, Y Hatching, and high Laser Speed. Full article
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17 pages, 20717 KiB  
Article
Three-Body Abrasive Wear-Resistance Characteristics of a 27Cr-Based 3V-3Mo-3W-3Co Multicomponent White Cast Iron with Different Ti Additions
by Riki Hendra Purba, Kazumichi Shimizu and Kenta Kusumoto
J. Manuf. Mater. Process. 2023, 7(1), 21; https://doi.org/10.3390/jmmp7010021 - 10 Jan 2023
Cited by 1 | Viewed by 1969
Abstract
A multicomponent white cast iron containing 5 wt.% each of Cr, V, Mo, W, and Co (MWCI) is known to have excellent wear-resistance properties due to the precipitation of some very hard carbides, such as MC, M2C, and M7C [...] Read more.
A multicomponent white cast iron containing 5 wt.% each of Cr, V, Mo, W, and Co (MWCI) is known to have excellent wear-resistance properties due to the precipitation of some very hard carbides, such as MC, M2C, and M7C3. However, it seems possible to improve the wear resistance of MWCI by increasing the carbide volume fraction (CVF). Thus, 27 wt.% Cr based on 3 wt.% each of V, W, Mo, and Co was simultaneously added into the white cast iron. To avoid the tendency of carbides to crack due to high M7C3 precipitation levels, titanium (0–2 wt.% Ti) was also added. A rubber wheel abrasive machine test according to the ASTM G65 standard with two different abrasive particle sizes (average: 75 and 300 μm) was used to evaluate the wear characteristics of the alloy. The results show that the wear resistance of these new alloys (0Ti, 1Ti, and 2Ti) is lower than that of MWCI in small silica sand, owing to the lower hardness. However, a different condition is present in large silica sand, for which the abrasive wear resistance of MWCI is lower than that of the 0Ti and 1Ti specimens. In addition, TiC precipitation effectively refined the size of M7C3 carbides and reduced their cracking tendency. Thus, the wear resistance of 1Ti is comparable to that of 0Ti, although it has a lower hardness factor. However, the wear resistance of the alloy significantly decreased following the addition of Ti by more than 1 wt.% due to the lower hardness and CVF. Therefore, it can be said that the abrasive wear characteristics of the alloy are not only affected by the hardness, but also by the micro-structural constituents (type, size, and volume fraction of carbides) and silica sand size. Full article
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