Journal of Manufacturing and Materials Processing

21 pages, 7769 KiB

Open AccessArticle

Enhancing Welding Productivity and Mitigation of Distortion in Dissimilar Welding of Ferritic-Martensitic Steel and Austenitic Stainless Steel Using Robotic A-TIG Welding Process

by Tushar Sonar, Mikhail Ivanov, Igor Shcherbakov, Evgeny Trofimov, Emiliya Khasanova, Muralimohan Cheepu and Kun Liu

J. Manuf. Mater. Process. 2024, 8(6), 283; https://doi.org/10.3390/jmmp8060283 - 5 Dec 2024

Viewed by 199

Abstract

The P91 martensitic steel and 304L austenitic stainless steels are two mainly used structural steels in power plants. The major problem in conventional multipass tungsten inert gas (TIG) welding of P91/304L steel is high heat input and joint distortion, increased cost and time [...] Read more.

The P91 martensitic steel and 304L austenitic stainless steels are two mainly used structural steels in power plants. The major problem in conventional multipass tungsten inert gas (TIG) welding of P91/304L steel is high heat input and joint distortion, increased cost and time associated with V groove preparation, filler rod requirement, preheating and welding in multiple passes, and labor efforts. Hence, in this study, a novel approach of robotically operated activated flux TIG (A-TIG) welding process and thin AlCoCrFeNi_2.1 eutectic high entropy alloy (EHEA) sheet as the interlayer was used to weld 6.14 mm thick P91 and 304L steel plates with 02 passes in butt joint configuration. The joints were qualified using visual examination, macro-etching, X-ray radiography testing and angular distortion measurement. The angular distortion of the joints was measured using a coordinate measuring machine (CMM) integrated with Samiso 7.5 software. The quality of the A-TIG welded joints was compared to the joints made employing multipass-TIG welding process and Inconel 82 filler rod in 07 passes. The A-TIG welded joints showed significant reduction in angular distortion and higher productivity. It showed a 55% reduction in angular distortion and 80% reduction in welding cost and time compared to the multipass-TIG welded joints. Full article

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30 pages, 6744 KiB

Open AccessReview

Recent Advances and Applications of Carbon Nanotubes (CNTs) in Machining Processes: A Review

by Reza Sallakhniknezhad, Hossein Ahmadian, Tianfeng Zhou, Guo Weijia, Senthil Kumar Anantharajan, Ayman M. Sadoun, Waleed Mohammed Abdelfattah and Adel Fathy

J. Manuf. Mater. Process. 2024, 8(6), 282; https://doi.org/10.3390/jmmp8060282 - 4 Dec 2024

Viewed by 348

Abstract

Recently, there has been much scholarly research on the applications of CNTs in various fields which can be attributed to their outstanding properties. For that matter, machining processes as the backbone of manufacturing technologies have also benefited greatly from the introduction of CNTs. [...] Read more.

Recently, there has been much scholarly research on the applications of CNTs in various fields which can be attributed to their outstanding properties. For that matter, machining processes as the backbone of manufacturing technologies have also benefited greatly from the introduction of CNTs. However, there is a lack of papers that provide a holistic overview on potential applications, which impedes focused and robust research in their application. In this work, after providing an outline of the methods used in increasing the productivity of machining processes, we will review the ways in which CNTs, known for their remarkable mechanical, chemical, electrical, and thermal characteristics, enhance the productivity of machining processes. We emphasize fit-for-purpose applications to determine the fate of CNTs use in machining processes. We examine the applications of CNTs in enhancing the mechanical characteristics of cutting tools, which include increased wear resistance, strength, and thermal conductivity, thereby extending tool life and performance. Additionally, this work highlights the application of nanofluids in MQL systems, where CNTs play a crucial role in reducing friction and enhancing thermal management, leading to reduced lubricant usage while maintaining cooling and lubrication effectiveness. Full article

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11 pages, 4307 KiB

Open AccessArticle

Local Remelting in Laser Powder Bed Fusion

by Janno Lehmann, Martin Weise, Markus Köhler, Frank von Lacroix, Vasily Ploshikhin and Klaus Dilger

J. Manuf. Mater. Process. 2024, 8(6), 281; https://doi.org/10.3390/jmmp8060281 - 4 Dec 2024

Viewed by 293

Abstract

In Laser Powder Bed Fusion, process material defects such as a lack of fusion, powder inclusions and cavities occur repeatedly by chance. These stochastically distributed defects can significantly reduce the mechanical performance of the components during operation. Possible in situ repair solutions such [...] Read more.

In Laser Powder Bed Fusion, process material defects such as a lack of fusion, powder inclusions and cavities occur repeatedly by chance. These stochastically distributed defects can significantly reduce the mechanical performance of the components during operation. Possible in situ repair solutions such as multiple remelting of specific layer areas are promising approaches to avoid these defects in the finished component, thus improving the overall properties. In this context, the present study investigates the remelting of artificially introduced defects using the example of M789 tool steel. In the first step, the process parameter settings and mechanical properties were evaluated using a tensile test, and the density of the local repair was examined using X-ray computer tomography and a metallographic analysis. The results demonstrate that the mechanical properties of the tensile test are comparable with those of the reference samples while successfully increasing the component quality. This indicates that defects that arise during the process can be remelted without the loss of mechanical characteristics. Full article

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13 pages, 9271 KiB

Open AccessArticle

Effect of Powder Preparation of FeNiCoCrMo_0.5Al_1.3 High-Entropy Alloy on the Phase Composition and Properties of High-Velocity Oxy-Fuel-Sprayed Coatings

by Anton Semikolenov, Nikolay Mamaev, Tatiana Larionova, Svetlana Shalnova and Oleg Tolochko

J. Manuf. Mater. Process. 2024, 8(6), 280; https://doi.org/10.3390/jmmp8060280 - 3 Dec 2024

Viewed by 412

Abstract

In this work, the effect of high-entropy alloy powder preparation on the coatings deposited via high-velocity oxygen fuel sprayings was studied. The powders of FeNiCoCrMo_0.5Al_1.3 composition were prepared by milling and gas atomization. The structures, porosity, phase composition, and microhardness [...] Read more.

In this work, the effect of high-entropy alloy powder preparation on the coatings deposited via high-velocity oxygen fuel sprayings was studied. The powders of FeNiCoCrMo_0.5Al_1.3 composition were prepared by milling and gas atomization. The structures, porosity, phase composition, and microhardness of the coatings produced from mechanically alloyed and gas-atomized powders were compared. The influence of milling parameters on the powder phase composition and morphology was studied. Milling at 600 rpm for 1.5 h allowed the production of mechanically alloyed powder with a homogeneous distribution of Fe, Ni, and Al and thin lamellas enriched with Co, Cr, and Mo. Despite the difference in the feedstock powders’ phase compositions, the phase compositions of the coatings deposited from mechanically alloyed and gas-atomized powders are the same consisting of BCC, FCC solutions, and oxide. The amount of FCC solutions and oxide in the coating depends on the size distribution of the sprayed powder. It was found that the phase composition and the properties of the coatings deposited from the mechanically alloyed and gas-atomized powders of similar sizes are similar. Full article

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17 pages, 17995 KiB

Open AccessArticle

The Wettability and High-Temperature Properties of Porous BN/Si₃N₄ Ceramics Bonded with SiTi22 Filler

by Yanli Zhuang, Hao Cheng, Xiao Wang, Limin Dong, Panpan Lin, Tiesong Lin, Peng He, Dan Li, Xinxin Jin and Jian Li

J. Manuf. Mater. Process. 2024, 8(6), 279; https://doi.org/10.3390/jmmp8060279 - 3 Dec 2024

Viewed by 319

Abstract

The wettability and high-temperature mechanical properties of porous BN/Si₃N₄ ceramics brazed with SiTi22 (wt. %) filler were studied. It is manifested that SiTi22 filler presents remarkable wetting and spreading capabilities on the porous BN/Si₃N₄ ceramic surface. An [...] Read more.

The wettability and high-temperature mechanical properties of porous BN/Si₃N₄ ceramics brazed with SiTi22 (wt. %) filler were studied. It is manifested that SiTi22 filler presents remarkable wetting and spreading capabilities on the porous BN/Si₃N₄ ceramic surface. An interfacial reaction layer is generated at the interface, and the thickness of the reaction layer initially grows and subsequently remains constant with the escalation of temperature. Carbon coating modification is beneficial to the wettability and high-temperature mechanical properties of porous BN/Si₃N₄ ceramics. The wetting driving force is mainly controlled by the interfacial reaction at the three-phase line of the wetting front. The mechanical properties of the carbon-coated joints are significantly enhanced in comparison with uncoated joints. The joint strength attains a maximum value of roughly 73 MPa in the shear test implemented at 800 °C. The strength of the joint is significantly enhanced mainly due to the TiN_0.7C_0.3 particles that consume energy by changing the crack propagation direction, and the SiC nanowires strengthen the connection by bridging. Full article

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15 pages, 4416 KiB

Open AccessArticle

Investigation of the Fabrication Parameters’ Influence on the Tensile Strength of 3D-Printed Copper-Filled Metal Composite Using Design of Experiments

by Vasileios Kyratsis, Anastasios Tzotzis, Apostolos Korlos and Nikolaos Efkolidis

J. Manuf. Mater. Process. 2024, 8(6), 278; https://doi.org/10.3390/jmmp8060278 - 2 Dec 2024

Viewed by 447

Abstract

The present study investigates the effects of fabrication parameters such as the nozzle temperature, the flow rate, and the layer thickness on the tensile strength of copper-filled metal-composite specimens. The selected material is a polylactic acid (PLA) filament filled with 65% copper powder. [...] Read more.

The present study investigates the effects of fabrication parameters such as the nozzle temperature, the flow rate, and the layer thickness on the tensile strength of copper-filled metal-composite specimens. The selected material is a polylactic acid (PLA) filament filled with 65% copper powder. Two sets of 27 specimens each were fabricated, and equivalent tensile experiments were carried out using a universal testing machine. The experiments were planned according to the full factorial design, with three printing parameters, as well as three value levels for each parameter. The analysis revealed that the temperature and the flow rate had the greatest impact on the yielded tensile strength, with their contribution percentages being 42.41% and 22.16%, respectively. In addition, a regression model was developed based on the experimental data to predict the tensile strength of the 3D-printed copper-filled metal composite within the investigated range of parameters. The model was evaluated using statistical methods, highlighting its increased accuracy. Finally, an optimization study was carried out according to the principles of the desirability function. The optimal fabrication parameters were determined to maximize the tensile strength of the specimens: temperature equal to 220 °C, flow rate equal to 110%, and layer thickness close to 0.189 mm. Full article

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19 pages, 279 KiB

Open AccessReview

Root Cause Analysis in Industrial Manufacturing: A Scoping Review of Current Research, Challenges and the Promises of AI-Driven Approaches

by Dominik Pietsch, Marvin Matthes, Uwe Wieland, Steffen Ihlenfeldt and Torsten Munkelt

J. Manuf. Mater. Process. 2024, 8(6), 277; https://doi.org/10.3390/jmmp8060277 - 2 Dec 2024

Viewed by 539

Abstract

The manufacturing industry must maintain high-quality standards while meeting customer demands for customization, reduced carbon footprint, and competitive pricing. To address these challenges, companies are constantly improving their production processes using quality management tools. A crucial aspect of this improvement is the root [...] Read more.

The manufacturing industry must maintain high-quality standards while meeting customer demands for customization, reduced carbon footprint, and competitive pricing. To address these challenges, companies are constantly improving their production processes using quality management tools. A crucial aspect of this improvement is the root cause analysis of manufacturing defects. In recent years, there has been a shift from traditional knowledge-driven approaches to data-driven approaches. However, there is a gap in the literature regarding a systematic overview of both methodological types, their overlaps, and the challenges they pose. To fill this gap, this study conducts a scoping literature review of root cause analysis in manufacturing, focusing on both data-driven and knowledge-driven approaches. For this, articles from IEEE Xplore, Scopus, and Web of Science are examined. This review finds that data-driven approaches have become dominant in recent years, with explainable artificial intelligence emerging as a particularly strong approach. Additionally, hybrid variants of root cause analysis, which combine expert knowledge and data-driven approaches, are also prevalent, leveraging the strengths of both worlds. Major challenges identified include dependence on expert knowledge, data availability, and management issues, as well as methodological difficulties. This article also evaluates the potential of artificial intelligence and hybrid approaches for the future, highlighting their promises in advancing root cause analysis in manufacturing. Full article

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36 pages, 5234 KiB

Open AccessArticle

Evaluating Energy Efficiency and Optimal Positioning of Industrial Robots in Sustainable Manufacturing

by Roman Ruzarovsky, Tibor Horak and Robert Bocak

J. Manuf. Mater. Process. 2024, 8(6), 276; https://doi.org/10.3390/jmmp8060276 - 1 Dec 2024

Viewed by 451

Abstract

Optimizing the energy efficiency of robotic workstations is a key aspect of industrial automation. This study focuses on the analysis of the relationship between the position of the robot base and its energy consumption and time aspects. A number of 6-axis robots, including [...] Read more.

Optimizing the energy efficiency of robotic workstations is a key aspect of industrial automation. This study focuses on the analysis of the relationship between the position of the robot base and its energy consumption and time aspects. A number of 6-axis robots, including the ABB IRB 120 robot, were investigated in this research by combining measurements and simulations using the energy consumption measurement module in the ABB RobotStudio 2024.1.1 environment. The objective of this study was to develop an energy consumption model that can identify the optimal robot positions to minimize energy costs and time losses. The results suggest that the strategic positioning of the robot has a significant impact on its performance and efficiency. These results demonstrate that the ideal working distance of the robots is approximately 50% of its maximum range, and displacements along the X and Z axes affect the energy and time consumption. These findings suggest the existence of a trade-off between time and energy efficiency, providing a basis for further research into the optimization of robotic systems. Thus, this work offers new perspectives for the design of efficient robotic workstations for cross-sensory applications. Full article

(This article belongs to the Special Issue Sustainable Manufacturing for a Better Future)

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26 pages, 5235 KiB

Open AccessArticle

Flexible Symbiosis for Simulation Optimization in Production Scheduling: A Design Strategy for Adaptive Decision Support in Industry 5.0

by Mohaiad Elbasheer, Francesco Longo, Giovanni Mirabelli and Vittorio Solina

J. Manuf. Mater. Process. 2024, 8(6), 275; https://doi.org/10.3390/jmmp8060275 - 30 Nov 2024

Viewed by 336

Abstract

In the rapidly evolving landscape of Industry 4.0 and the transition towards Industry 5.0, manufacturing systems face the challenge of adapting to dynamic, hyper-customized demands. Current Simulation Optimization (SO) systems struggle with the flexibility needed for quick reconfiguration, often requiring time-consuming, resource-intensive efforts [...] Read more.

In the rapidly evolving landscape of Industry 4.0 and the transition towards Industry 5.0, manufacturing systems face the challenge of adapting to dynamic, hyper-customized demands. Current Simulation Optimization (SO) systems struggle with the flexibility needed for quick reconfiguration, often requiring time-consuming, resource-intensive efforts to develop custom models. To address this limitation, this study introduces an innovative SO design strategy that integrates three flexible simulation modeling techniques—template-based, structural modeling, and parameterization. The goal of this integrated design strategy is to enable the rapid adaptation of SO systems to diverse production environments without extensive re-engineering. The proposed SO versatility is validated across three manufacturing scenarios (flow shop, job shop, and open shop scheduling) using modified benchmark instances from Taillard’s dataset. The results demonstrate notable effectiveness in optimizing production schedules across these diverse scenarios, enhancing decision-making processes, and reducing SO development efforts. Unlike conventional SO system design, the proposed design framework ensures real-time adaptability, making it highly relevant to the dynamic requirements of Industry 5.0. This strategic integration of flexible modeling techniques supports efficient decision support, minimizes SO development time, and reinforces manufacturing resilience, therefore sustaining competitiveness in modern industrial ecosystems. Full article

(This article belongs to the Special Issue Smart Manufacturing in the Era of Industry 4.0)

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22 pages, 13474 KiB

Open AccessArticle

Multimodal Human–Robot Interaction Using Gestures and Speech: A Case Study for Printed Circuit Board Manufacturing

by Ángel-Gabriel Salinas-Martínez, Joaquín Cunillé-Rodríguez, Elías Aquino-López and Angel-Iván García-Moreno

J. Manuf. Mater. Process. 2024, 8(6), 274; https://doi.org/10.3390/jmmp8060274 - 30 Nov 2024

Viewed by 237

Abstract

In recent years, technologies for human–robot interaction (HRI) have undergone substantial advancements, facilitating more intuitive, secure, and efficient collaborations between humans and machines. This paper presents a decentralized HRI platform, specifically designed for printed circuit board manufacturing. The proposal incorporates many input devices, [...] Read more.

In recent years, technologies for human–robot interaction (HRI) have undergone substantial advancements, facilitating more intuitive, secure, and efficient collaborations between humans and machines. This paper presents a decentralized HRI platform, specifically designed for printed circuit board manufacturing. The proposal incorporates many input devices, including gesture recognition via Leap Motion and Tap Strap, and speech recognition. The gesture recognition system achieved an average accuracy of 95.42% and 97.58% for each device, respectively. The speech control system, called Cellya, exhibited a markedly reduced Word Error Rate of 22.22% and a Character Error Rate of 11.90%. Furthermore, a scalable user management framework, the decentralized multimodal control server, employs biometric security to facilitate the efficient handling of multiple users, regulating permissions and control privileges. The platform’s flexibility and real-time responsiveness are achieved through advanced sensor integration and signal processing techniques, which facilitate intelligent decision-making and enable accurate manipulation of manufacturing cells. The results demonstrate the system’s potential to improve operational efficiency and adaptability in smart manufacturing environments. Full article

(This article belongs to the Special Issue Smart Manufacturing in the Era of Industry 4.0)

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28 pages, 15253 KiB

Open AccessArticle

Impact of Uniaxial Pre-Strains on the Forming Limit Curve (FLC) of CuZn 70-30 Brass Sheets for Enhanced Formability in Production Applications Using the Nakajima Test

by Aseel Hamad Abed, Raed R. Shwaish, Asaad Ali Abbas, Baha S. Mahdi and Waleed Ahmed

J. Manuf. Mater. Process. 2024, 8(6), 273; https://doi.org/10.3390/jmmp8060273 - 28 Nov 2024

Viewed by 432

Abstract

Brass sheets are extensively utilized in the automotive, electrical, and other industries, where an in-depth understanding of their formability is crucial for achieving optimal performance in production applications. This study investigates the influence of uniaxial pre-strains on the Forming Limit Curve (FLC) of [...] Read more.

Brass sheets are extensively utilized in the automotive, electrical, and other industries, where an in-depth understanding of their formability is crucial for achieving optimal performance in production applications. This study investigates the influence of uniaxial pre-strains on the Forming Limit Curve (FLC) of CuZn 70-30 brass sheets, which aims to enhance their formability by identifying and optimizing key forming parameters. Adding a new variable, the impact of uniaxial pre-strain upon FLC, was our aim of this study and, consequently, the CuZn 70-30 brass sheet formability using punch-stretching tests with purpose-built tools, we experimentally obtained FLCs for brass sheets under varying levels of pre-strain (0.04, 0.06, and 0.08) applied through uniaxial tension by using Nakajima tests with purpose-built tools. The objective was to understand how specific factors such as punch parameters, punch corner radius, and strain rate impact the FLC and, consequently, the brass sheets formability. Results indicate a distinct trend of increasing pre-strain levels leading to a significant rise in minor strain capacity along the right portionof the FLC, with a comparatively insignificant effect on the left. This consistent elevation across strain paths suggests improved formability due to pre-straining, highlighting the potential for optimized manufacturing processes and enhanced product quality across industrial applications. Full article

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23 pages, 2332 KiB

Open AccessArticle

Concept for Predictive Quality in Carbon Fibre Manufacturing

by Sebastian Gellrich, Thomas Groetsch, Maxime Maghe, Claudia Creighton, Russell Varley, Anna-Sophia Wilde and Christoph Herrmann

J. Manuf. Mater. Process. 2024, 8(6), 272; https://doi.org/10.3390/jmmp8060272 - 28 Nov 2024

Viewed by 349

Abstract

Remarkable mechanical properties make carbon fibres attractive for many industrial applications. However, up to today, carbon fibres come with a significant environmental backpack, undermining their advantages in light of a strong demand for absolute sustainability of new industrial products. Consequently, there is considerable [...] Read more.

Remarkable mechanical properties make carbon fibres attractive for many industrial applications. However, up to today, carbon fibres come with a significant environmental backpack, undermining their advantages in light of a strong demand for absolute sustainability of new industrial products. Consequently, there is considerable demand for high-quality carbon fibre manufacturing, low waste production, or alternative precursor systems allowing minimization of environmental impacts. Therefore, this paper investigates the capabilities of data analytics with a special emphasis on predictive quality in order to advance the quality management of carbon fibre manufacturing. Although existing research supports the applicability of machine learning in carbon fibre production, there is a notable scarcity of case studies and a lack of a structured repetitive data analytics concept. To address this gap, the study proposes a holistic framework for predictive quality in carbon fibre manufacturing that outlines specific data analytics requirements based on the process properties of carbon fibre production. Additionally, it introduces a systematic method for processing trend data. Finally, a case study of polyacrylonitrile (PAN)-based carbon fibre manufacturing exemplifies the concept, giving indications on feature importance and sensitivity related to the expected fibre properties. Future research can build on the comprehensive overview of predictive quality potentials and its implementation concept by extending the underlying data set and investigating the transfer to alternative precursors. Full article

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12 pages, 21287 KiB

Open AccessArticle

Microstructure, Physical-Mechanical, and Magnetic Characteristics of a Butt-Welded Joint Obtained by Rotary Friction Welding Technology of Bimetallic Pipe

by Evgeniia Putilova, Kristina Kryucheva, Ivan Kamantsev and Elena Priymak

J. Manuf. Mater. Process. 2024, 8(6), 271; https://doi.org/10.3390/jmmp8060271 - 28 Nov 2024

Viewed by 392

Abstract

The development of technology, including in the oil and gas industry, necessitates the creation of materials with special sets of properties, such as high strength characteristics combined with corrosion resistance. One such material is bimetallic pipe, but we are faced with the problem [...] Read more.

The development of technology, including in the oil and gas industry, necessitates the creation of materials with special sets of properties, such as high strength characteristics combined with corrosion resistance. One such material is bimetallic pipe, but we are faced with the problem of creating extended structures and obtaining high-quality butt-welded joints of such industrial bimetallic pipes. The microstructure in different parts of the thermomechanically influenced zone of a butt-welded joint of a bimetallic pipe obtained by rotary friction welding (RFW) was investigated by optical and electron microscopy methods. It was established that during rotary friction welding of the bimetallic pipe in standard mode, one metal flowed into the zone of another. This could be explained by the different plastic properties of the steels that made up the bimetal, which must be taken into account in future welding. Standard RFW mode did not result in the formation of a high-quality weld; defects and discontinuities were observed in the joint area. The maximum hardness values were observed directly in the weld joint. It is concluded that rotary friction welding can be used as a welding technology for bimetallic pipes, but the most attention should be paid to the welding mode to obtain a high-quality butt-welded joint. Full article

(This article belongs to the Special Issue Advances in Dissimilar Metal Joining and Welding)

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17 pages, 42128 KiB

Open AccessArticle

Adaptation of Conventional Toolpath-Generation Software for Use in Curved-Layer Fused Deposition Modeling

by Samuel Maissen, Severin Zürcher and Michael Wüthrich

J. Manuf. Mater. Process. 2024, 8(6), 270; https://doi.org/10.3390/jmmp8060270 - 28 Nov 2024

Viewed by 593

Abstract

In 3D printing, the layered structure often results in artifacts. This effect becomes stronger for surfaces with a lower ramp angle. This effect can be mitigated by manufacturing parts with non-planar layers that fit the parts’ surface geometry. Using the open-source slicing software [...] Read more.

In 3D printing, the layered structure often results in artifacts. This effect becomes stronger for surfaces with a lower ramp angle. This effect can be mitigated by manufacturing parts with non-planar layers that fit the parts’ surface geometry. Using the open-source slicing software PrusaSlicer. an algorithm was developed to modify the slicer’s input and output data in a way that fits parts with low ramp angle surfaces. To achieve consistent part quality, all layers were modified to be printed in a non-planar way. The test results indicate that the proposed methods can significantly reduce surface roughness. Although the algorithm works well for parts with a flat base and vertical walls, it would need to be highly adapted to work for different part geometries. Additionally, compared to other algorithms used in Curved-Layer Fused Deposition Modeling (CLFDM), the changed layer structure introduces a changed visual appearance of parts. Full article

(This article belongs to the Special Issue Advances in Additive Manufacturing and Material Characterization Techniques)

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12 pages, 1782 KiB

Open AccessReview

Combining Neural Networks and Genetic Algorithms to Understand Composition–Microstructure–Property Relationships in Additively Manufactured Metals

by Sooraj Patel, Anvesh Nathani, Amin Poozesh, Shuozhi Xu, Pejman Kazempoor and Iman Ghamarian

J. Manuf. Mater. Process. 2024, 8(6), 269; https://doi.org/10.3390/jmmp8060269 - 28 Nov 2024

Viewed by 387

Abstract

Additive manufacturing (AM) has revolutionized the production of complex metallic components by enabling the direct fabrication of intricate geometries from 3D model data. Despite its advantages in reducing material waste and customization of mechanical properties, AM faces challenges related to microstructural heterogeneity and [...] Read more.

Additive manufacturing (AM) has revolutionized the production of complex metallic components by enabling the direct fabrication of intricate geometries from 3D model data. Despite its advantages in reducing material waste and customization of mechanical properties, AM faces challenges related to microstructural heterogeneity and mechanical property variability. This review highlights the structure–property relationships in additively manufactured metals, emphasizing how heterogeneous microstructure influences yield strength and fracture toughness. Phenomenological equations are provided based on the integration of neural networks and genetic algorithm-based models to predict mechanical properties from composition and microstructural features. We also outline key considerations such as acquiring high-fidelity datasets and understanding mathematical correlations within the data needed to formulate phenomenological equations. Full article

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16 pages, 8683 KiB

Open AccessArticle

Thermal and Mechanical Properties of Nano-TiC-Reinforced 18Ni300 Maraging Steel Fabricated by Selective Laser Melting

by Francisco F. Leite, Indrani Coondoo, João S. Vieira, José M. Oliveira and Georgina Miranda

J. Manuf. Mater. Process. 2024, 8(6), 268; https://doi.org/10.3390/jmmp8060268 - 28 Nov 2024

Viewed by 496

Abstract

Additive manufacturing (AM) has brought new possibilities to the moulding industry, particularly regarding the use of high-performance materials as maraging steels. This work explores 18Ni300 maraging steel reinforced with 4.5 vol.% TiC nanoparticles, fabricated by Selective Laser Melting (SLM), addressing the effect of [...] Read more.

Additive manufacturing (AM) has brought new possibilities to the moulding industry, particularly regarding the use of high-performance materials as maraging steels. This work explores 18Ni300 maraging steel reinforced with 4.5 vol.% TiC nanoparticles, fabricated by Selective Laser Melting (SLM), addressing the effect of post-fabrication aging treatment on both thermal and mechanical properties. Design of Experiments (DoE) was used to generate twenty-five experimental groups, in which laser power, scanning speed, and hatch distance were varied across five levels, with the aim of generating conclusions on optimal fabrication conditions. A comprehensive analysis was performed, starting with the nanocomposite feedstock and then involving the microstructural, mechanical, and thermal characterisation of SLM-fabricated nanocomposites. Nanocomposite relative density varied between 92.84% and 99.73%, and the presence of martensite, austenite, and TiC was confirmed in the as-built and heat-treated conditions. Results demonstrated a hardness of 411 HV for the as-built 18Ni300-TiC nanocomposite, higher than that of the non-reinforced steel, and this was further increased by performing aging treatment, achieving a hardness of 673 HV. Thermal conductivity results showed an improvement from ~12 W/m·K to ~19 W/m·K for nano-TiC-reinforced 18Ni300 when comparing values before and after heat treatment, respectively. Results showed that the addition of TiC nanoparticles to 18Ni300 maraging steel led to a combined thermal and mechanical performance suited for applications in which heat extraction is required, as in injection moulding. Full article

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20 pages, 8785 KiB

Open AccessArticle

Effect of Powder Recycling on the Surface and Selected Technological Properties of M300 Maraging Steel Produced via the SLM Method

by Abdesselam Mechali, Josef Hlinka, Michal Kresta, Marin Petrovic, Jakub Mesicek, Ibrahim Jahan, Jiri Hajnys and Jana Petru

J. Manuf. Mater. Process. 2024, 8(6), 267; https://doi.org/10.3390/jmmp8060267 - 27 Nov 2024

Viewed by 459

Abstract

This study delves into selective laser melting (SLM). By using M300 steel in virgin and recycled powder form (after 20 cycles), with the aim of reducing the cost of printing for the practical application of M300 maraging steel, a comprehensive comparison between the [...] Read more.

This study delves into selective laser melting (SLM). By using M300 steel in virgin and recycled powder form (after 20 cycles), with the aim of reducing the cost of printing for the practical application of M300 maraging steel, a comprehensive comparison between the two types of powder was evaluated. The powder’s morphology was analyzed using scanning electron microscopy (SEM) and backscattered electrons (BSE). The particles were seen to have a spherical shape, with a notable number of satellites attached to their surfaces. The particle size distribution (PSD) was examined and ranged from 10 to 90 µm for both powders. In addition, the porosity exhibited an average value of 0.07% for the virgin powder and 0.10% for the recycled powder. The microstructure was examined. Additionally, the surface wettability was tested, and it was seen to display wetting behavior for both types of powder, while blackened surfaces showed a higher wetting angle than untreated surfaces (hydrophobic). The 2D roughness measurements showed that the recycled powder had no significant difference from the virgin powder (Ra = 5.33 µm, Rz = 24.17 µm) before blackening and (Ra = 5.48 µm, Rz = 24.07 µm) after blackening. Corrosion tests proved that the recycled powder did not affect the corrosion properties of the material, while blackening caused partial surface corrosion in both types of samples, regardless of the used powder. Full article

(This article belongs to the Special Issue Advances in Additive Manufacturing and Material Characterization Techniques)

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21 pages, 29199 KiB

Open AccessArticle

On Forming Characteristics of Hems by Means of Incremental Sheet Forming

by Dennis Steinfels and David Bailly

J. Manuf. Mater. Process. 2024, 8(6), 266; https://doi.org/10.3390/jmmp8060266 - 26 Nov 2024

Viewed by 324

Abstract

Given the need for versatile joining processes, form-fit joining is gaining increasing importance. Although it has known limitations and complexity, roller hemming remains widely used due to its flexibility. Here, the novel Incremental Sheet Forming (ISF) hemming technique has the potential to expand [...] Read more.

Given the need for versatile joining processes, form-fit joining is gaining increasing importance. Although it has known limitations and complexity, roller hemming remains widely used due to its flexibility. Here, the novel Incremental Sheet Forming (ISF) hemming technique has the potential to expand the range of applications and process limits. It has already proven effective in preliminary works for joining comparatively small radii without wrinkles and cracks. However, a deeper understanding of the dominant material flow and deformation mechanism during forming is required to fully exploit its potential. This study aims to conduct a detailed examination of this technology through experimental and numerical investigations. Strain measurements on convex and concave hems provide insights into the material flow. A comparison of the forming mechanism for both processes is made using straight hems. The results show that ISF hemming has a favorable material flow for compensating cracks and wrinkles in curved hems. Additionally, it induces strains across the entire hem area, reaching higher values than those achieved with roller hemming. One reason for this is the forming mechanism, which combines tension, compression and shear, whereas roller hemming primarily involves bending and compression of the hemming radius. Full article

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14 pages, 4754 KiB

Open AccessArticle

Optimizing the Material Extrusion Process for Investment Casting Mould Production

by Pablo Rodríguez-González, Pablo Zapico, Sofía Peláez-Peláez, María Ángeles Castro-Sastre and Ana Isabel Fernández-Abia

J. Manuf. Mater. Process. 2024, 8(6), 265; https://doi.org/10.3390/jmmp8060265 - 23 Nov 2024

Viewed by 508

Abstract

This study investigates the optimization of the Material Extrusion (MEX) process for producing polylactic acid (PLA) patterns used in investment casting moulds, specifically targeting the casting of non-ferrous alloys such as brass. Key MEX process parameters—layer thickness, wall thickness, infill density, and post-processing [...] Read more.

This study investigates the optimization of the Material Extrusion (MEX) process for producing polylactic acid (PLA) patterns used in investment casting moulds, specifically targeting the casting of non-ferrous alloys such as brass. Key MEX process parameters—layer thickness, wall thickness, infill density, and post-processing with dichloromethane vapour for surface enhancement—were systematically analyzed for their impact on mould quality. Results indicate that an optimized combination of MEX parameters yields moulds with high dimensional accuracy, low surface roughness, and minimal pattern residue within the mould cavity. These optimized moulds were subsequently used in brass casting, with the final cast parts evaluated for dimensional precision and surface finish. The study concludes that PLA patterns manufactured via optimized MEX parameters provide a precise, cost-effective, and easy-to-implement solution for industry applications. Additionally, this process is environmentally friendly and presents clear advantages over other pattern-making methods, offering a sustainable alternative for producing complex metal parts with reduced environmental impact. The findings underscore the significant role of post-processing in enhancing mould quality and, consequently, the quality of the cast parts. Full article

(This article belongs to the Special Issue Advances in Additive Manufacturing and Material Characterization Techniques)

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14 pages, 13014 KiB

Open AccessArticle

A Design Strategy for Surface Modification and Decarburization to Achieve Enhanced Mechanical Properties in Additively Manufactured Stainless Steel

by Soumya Sridar, Noah Sargent, Stephanie Prochaska, Mitra Shabani, Owen Hildreth and Wei Xiong

J. Manuf. Mater. Process. 2024, 8(6), 264; https://doi.org/10.3390/jmmp8060264 - 20 Nov 2024

Viewed by 452

Abstract

Post-processing of additively manufactured components, including the removal of support structures and the reduction in surface roughness, presents significant challenges. Conventional milling struggles to access internal cavities, while the Self-Terminating Etching Process (STEP) offers a promising solution. STEP effectively smooths surfaces and dissolves [...] Read more.

Post-processing of additively manufactured components, including the removal of support structures and the reduction in surface roughness, presents significant challenges. Conventional milling struggles to access internal cavities, while the Self-Terminating Etching Process (STEP) offers a promising solution. STEP effectively smooths surfaces and dissolves supports without substantial changes in geometry. However, it can lead to compositional changes and precipitation, affecting the material properties and necessitating a design strategy to mitigate them. In this study, STEP is applied to stainless steel 316L (SS316L) produced via laser powder bed fusion, reducing surface roughness from 7 to 2 μm. After STEP, the surface carbon exhibited a threefold increase, leading to the formation of M₂₃C₆ clusters. This significantly impacted the yield strength, resulting in a 37% reduction compared to the as-built condition. The key to overcoming this challenge was using computational simulations, which guided the determination of the decarburization conditions: 1000 °C for 60 min, ensuring maximum M₂₃C₆ dissolution and surface carbon reduction with minimal grain coarsening. Following these conditions, the yield strength of SS316L was restored to the level observed in the as-built condition. These findings underscore the potential of the proposed design strategy to enhance the mechanical performance of additively manufactured components significantly. Full article

(This article belongs to the Special Issue Advances in Additive Manufacturing and Material Characterization Techniques)

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23 pages, 7016 KiB

Open AccessArticle

Build Orientation-Driven Anisotropic Fracture Behaviour in Polymer Parts Fabricated by Powder Bed Fusion

by Karthik Ram Ramakrishnan and Jagan Selvaraj

J. Manuf. Mater. Process. 2024, 8(6), 263; https://doi.org/10.3390/jmmp8060263 - 20 Nov 2024

Viewed by 648

Abstract

Additive manufacturing (AM) enables fabricating intricate objects with complex geometries previously unattainable through conventional methods. This process encompasses various techniques, including powder bed fusion (PBF), such as selective laser sintering (SLS) and multi-jet fusion (MJF). These techniques involve selectively melting powdered polymer material, [...] Read more.

Additive manufacturing (AM) enables fabricating intricate objects with complex geometries previously unattainable through conventional methods. This process encompasses various techniques, including powder bed fusion (PBF), such as selective laser sintering (SLS) and multi-jet fusion (MJF). These techniques involve selectively melting powdered polymer material, predominantly utilizing engineering thermoplastics layer by layer to create solid components. Although their mechanical properties have been extensively characterised, very few works have addressed the influence of additive manufacturing on fracture behaviour. In this context, we present our work demonstrating the presence of anisotropy in fracture behaviour due to the build orientation as well as the PBF methods. To evaluate this anisotropy, the fracture behaviour of polyamide 12 polymer manufactured by SLS and MJF were investigated with experiments and numerical modelling of Mode I compact tension (CT) specimens. Experiments were monitored by digital image correlation (DIC) and infra-red thermography (IRT). Additionally, the fractured surfaces are analysed using scanning electron microscopy. Comparative analyses between SLS and MJF technologies unveiled dissimilar trends in mechanical strength, build-orientation effects, and fracture properties. Full article

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11 pages, 6390 KiB

Open AccessArticle

Development of Polymer Hydrophobic Surfaces Through Combined Laser Ablation and Hot Embossing Processes

by Esmaeil Ghadiri Zahrani, Amirmohmmad Fakharzadeh Jahromi and Bahman Azarhoushang

J. Manuf. Mater. Process. 2024, 8(6), 262; https://doi.org/10.3390/jmmp8060262 - 20 Nov 2024

Viewed by 486

Abstract

The development of hydrophobicity on polymer surfaces in mass production is one of the most critical challenges in the plastic industry. This paper deals with a novel combined hot embossing process in which femtosecond laser ablation is utilized to texture the embossing stamps. [...] Read more.

The development of hydrophobicity on polymer surfaces in mass production is one of the most critical challenges in the plastic industry. This paper deals with a novel combined hot embossing process in which femtosecond laser ablation is utilized to texture the embossing stamps. By controlling the process temperature and axial forces, the laser textures were transferred to polymer surfaces, successfully resulting in hydrophobicity. Four different polymers, including ABS, PP, PA, and PC, along with two different laser textures, namely ball and pyramid, were tested. The laser and hot embossing parameters under which the textures were transferred to the polymers are introduced. The critical micro- and nano-features of the transferred textures that resulted in high hydrophobic contact angles are also discussed. The results indicate that PP and ABS have higher contact angles, respectively, while under the given parameters, PA and PC did not exhibit hydrophobic surfaces. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology)

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17 pages, 8481 KiB

Open AccessReview

A Review of Magnetic Abrasive Finishing for the Internal Surfaces of Metal Additive Manufactured Parts

by Liaoyuan Wang, Yuli Sun, Zhongmin Xiao, Fanxuan Yang, Shijie Kang, Yanlei Liu and Dunwen Zuo

J. Manuf. Mater. Process. 2024, 8(6), 261; https://doi.org/10.3390/jmmp8060261 - 16 Nov 2024

Viewed by 774

Abstract

With the rapid development of high-end manufacturing industries such as aerospace and national defense, the demand for metal additive manufactured parts with complex internal cavities has been steadily increasing. However, the finishing of complex internal surfaces, especially for irregularly shaped parts, remains a [...] Read more.

With the rapid development of high-end manufacturing industries such as aerospace and national defense, the demand for metal additive manufactured parts with complex internal cavities has been steadily increasing. However, the finishing of complex internal surfaces, especially for irregularly shaped parts, remains a significant challenge due to their intricate geometries. Through a comparative analysis of common finishing methods, the distinctive characteristics and applicability of magnetic abrasive finishing (MAF) are highlighted. To meet the finishing needs of complex metal additive manufactured parts, this paper reviews the current research on magnetic abrasive finishing devices, processing mechanisms, the development of magnetic abrasives, and the MAF processes for intricate internal cavities. Future development trends in MAF for complex internal cavities in additive manufactured parts are also explored; these are (1) investigating multi-technology composite magnetic abrasive finishing equipment designed for complex internal surfaces; (2) studying the dynamic behavior of multiple magnetic abrasive particles in complex cavities and their material removal mechanisms; (3) developing high-performance magnetic abrasives suitable for demanding conditions; and (4) exploring the MAF process for intricate internal surfaces. Full article

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18 pages, 7690 KiB

Open AccessArticle

A Comparison of the Microstructure and Mechanical Properties of RSW and RFSSW Joints in AA6061-T4 for Automotive Applications

by Damon Gale, Taylor Smith, Yuri Hovanski, Kate Namola and Jeremy Coyne

J. Manuf. Mater. Process. 2024, 8(6), 260; https://doi.org/10.3390/jmmp8060260 - 14 Nov 2024

Viewed by 722

Abstract

To reduce vehicle weight and improve energy efficiency, automotive manufacturers are increasingly using aluminum body panels. However, the traditional joining method, Resistance Spot Welding (RSW), presents challenges like weld porosity and electrode degradation when used with aluminum. These issues have driven the industry [...] Read more.

To reduce vehicle weight and improve energy efficiency, automotive manufacturers are increasingly using aluminum body panels. However, the traditional joining method, Resistance Spot Welding (RSW), presents challenges like weld porosity and electrode degradation when used with aluminum. These issues have driven the industry to explore alternative, more effective methods for joining aluminum in vehicle manufacturing such as Refill Friction Stir Spot Welding (RFSSW). This research reports on a comparison of the microstructure and mechanical properties of welds made with RSW and RFSSW in AA6061-T4 automotive sheets. This comparison includes CT scanning, optical and SEM imaging, statistical microscopy, hardness testing, tensile testing, and fatigue testing. The results showed that RFSSW produced fully consolidated welds with a refined, equiaxed grain structure that outperformed RSW’s dendritic grain structure by as much as 73% in tensile testing and 2600% in fatigue testing. These results suggest that future designs utilizing RFSSW could incorporate fewer joints, reducing processing time, energy consumption, and tool wear. Cost studies also found that RFSSW consumes 2.5% of the energy that RSW does per joint, demonstrating that RFSSW is positioned as the preferred method for joining aluminum automotive sheets. Full article

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13 pages, 12590 KiB

Open AccessArticle

Stainless Steel 316L Fabricated by Fused Deposition Modeling Process: Microstructure, Geometrical and Mechanical Properties

by Maria Zaitceva, Anton Sotov, Anatoliy Popovich and Vadim Sufiiarov

J. Manuf. Mater. Process. 2024, 8(6), 259; https://doi.org/10.3390/jmmp8060259 - 14 Nov 2024

Viewed by 676

Abstract

Additive manufacturing (AM) methods are widely used to produce metal products. However, the cost of equipment for processes based on material melting is high. In this paper, a promising, less expensive method of producing metal products from metal-filled Ultrafuse 316L filament by FDM [...] Read more.

Additive manufacturing (AM) methods are widely used to produce metal products. However, the cost of equipment for processes based on material melting is high. In this paper, a promising, less expensive method of producing metal products from metal-filled Ultrafuse 316L filament by FDM was investigated. The aim of this work was to compare the debinding methods and investigate the microstructure, phase composition, and geometric and mechanical properties. The results showed that catalytic debinding can be replaced by thermal debinding as no significant effect on the structure and properties was found. In addition, a filament study was performed and data on the particle size distribution, morphology, and phase composition of the metal particles were obtained. Thermodynamic modeling was performed to better understand the phase distribution at the sintering stage. The δ-Fe fraction influencing the corrosion properties of the material was estimated. The conformity of geometric dimensions to the original 3D models was evaluated using 3D scanning. The applied printing and post-processing parameters allowed us to obtain a density of 98%. The material and technology represent a promising direction for applications in the field of lightweight engineering in the manufacturing of parts with bioinspired designs, shells, and sparse filler structures with useful porosity designs (like helicoidal structures). Full article

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24 pages, 6347 KiB

Open AccessArticle

Effect of Different Annealing Methods on ULTEM 9085 Parts Manufactured by Material Extrusion

by Javaid Butt, Habib Afsharnia, Md Ashikul Alam Khan and Vahaj Mohaghegh

J. Manuf. Mater. Process. 2024, 8(6), 258; https://doi.org/10.3390/jmmp8060258 - 14 Nov 2024

Viewed by 539

Abstract

A common practice of improving the performance of parts manufactured by material extrusion is annealing. In this work, ULTEM 9085 parts were subjected to three different annealing methods to compare their effectiveness in terms of dimensional stability, hardness, surface roughness, tensile strength, microstructure [...] Read more.

A common practice of improving the performance of parts manufactured by material extrusion is annealing. In this work, ULTEM 9085 parts were subjected to three different annealing methods to compare their effectiveness in terms of dimensional stability, hardness, surface roughness, tensile strength, microstructure and flexural strength. The annealing methods involved heating ULTEM 9085 parts inside an oven in three different ways: direct oven annealing by placing the parts on a tray, fluidized bed annealing with sharp sand surrounding the parts and sandwiching the parts between metal plates. Annealing for all three methods was conducted at temperatures of 180 °C, 190 °C and 200 °C with time intervals of 1 h, 2 h and 3 h. The results showed that direct oven annealing provides consistent results under all scenarios. Better dimensional accuracies were observed with fluidized bed annealing, and metal plate annealing is better suited to ensuring an improved surface finish and higher hardness values. For the tensile test, direct oven annealing yielded the most consistent and optimal results with an increase of up to 28.1% in tensile strength, whereas the other two methods performed better at lower temperatures. Direct oven annealing also led to improved ductility and higher elongation at break. Moreover, microstructural analysis of the fracture surfaces indicated enhanced coalescence for direct oven annealing. In terms of flexural testing, metal plate annealing proved to be more effective, with an increase of up to 13.9% in flexural strength. The other two methods demonstrated consistent results, with direct oven annealing showing slightly higher values compared with unannealed ULTEM 9085 samples. This work provides a useful comparison among different annealing methods that can be used to enhance the performance of ULTEM 9085 parts for different engineering applications. Full article

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12 pages, 2990 KiB

Open AccessArticle

The Effects of Cutting Parameters on Cutting Force and Tribological Properties of Machined Surface Under Dry Turning of AISI304L Austenitic Stainless Steel

by Gábor Kónya, Béla Csorba, Norbert Szabó and Zsolt F. Kovács

J. Manuf. Mater. Process. 2024, 8(6), 257; https://doi.org/10.3390/jmmp8060257 - 14 Nov 2024

Viewed by 538

Abstract

In this study, the effects of cutting speed and feed rate on the roughness parameters R_a, R_z, R_sk, R_ku, R_pk, R_vk, and A₂ were examined during machining with coated carbide [...] Read more.

In this study, the effects of cutting speed and feed rate on the roughness parameters R_a, R_z, R_sk, R_ku, R_pk, R_vk, and A₂ were examined during machining with coated carbide tools in a dry environment. The authors introduced the R_vk/R_pk ratio, a coefficient that facilitates a simpler evaluation of surface wear resistance. Specifically, if this ratio is greater than 1, the surface is more wear-resistant, while values less than 1 indicate a higher tendency for surface wear. The Taguchi OA method was used to analyze and identify the significance of technological parameters on output characteristics. Based on the results, it was established that feed rate has the greatest impact on all output characteristics. The highest cutting force was measured at a cutting speed of 60 m/min and a feed rate of 0.15 mm/rev, attributed to the fact that at lower cutting speeds, the base material does not soften while the cross-sectional area of the chip increases. To achieve the lowest R_a and R_z surface roughness, a cutting speed of 100 m/min and a feed rate of 0.05 mm/rev are recommended. If the goal is to enhance surface wear resistance and improve oil retention capability, machining with a cutting speed of 80–100 m/min and a feed rate of 0.15 mm/rev is advisable, as the coarser machining increases both the R_vk/R_pk ratio and the oil-retaining pocket size, which together improve the wear resistance of the machined surface. Full article

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20 pages, 21860 KiB

Open AccessArticle

Geometric and Mechanical Properties of Ti6Al4V Skeletal Gyroid Structures Produced by Laser Powder Bed Fusion for Biomedical Implants

by Cong Hou, Max Goris, Dries Rosseel, Bey Vrancken and Kathleen Denis

J. Manuf. Mater. Process. 2024, 8(6), 256; https://doi.org/10.3390/jmmp8060256 - 13 Nov 2024

Viewed by 573

Abstract

Skeletal gyroid structures possess promising applications in biomedical implants, owing to their smooth and continuously curved surfaces, open porosity, and customisable mechanical properties. This study simulated the geometric properties of Ti6Al4V skeletal gyroid structures, with relative densities ranging from 1.83% to 98.17%. The [...] Read more.

Skeletal gyroid structures possess promising applications in biomedical implants, owing to their smooth and continuously curved surfaces, open porosity, and customisable mechanical properties. This study simulated the geometric properties of Ti6Al4V skeletal gyroid structures, with relative densities ranging from 1.83% to 98.17%. The deformation behaviour of these structures was investigated through a combination of uniaxial compression tests and simulations, within a relative density range of 13.33% to 50% (simulation) and 15.19% to 41.69% (experimental tests). The results established explicit analytical correlations of pore size and strut diameter with the definition parameters of the structures, enabling precise control of these dimensions. Moreover, normalised Young’s modulus (ranging from 1.05% to 20.77% in simulations and 1.65% to 15.53% in tests) and normalised yield stress (ranging from 1.75% to 17.39% in simulations and 2.09% to 13.95% in tests) were found to be power correlated with relative density. These correlations facilitate the design of gyroid structures with low stiffness to mitigate the stress-shielding effect. The presence of macroscopic 45° fractures in the gyroid structures confirmed that the primary failure mechanism is induced by shear loads. The observed progressive failure and plateau region proved the bending-dominant behaviour and highlighted their excellent deformability. Additionally, the anisotropy of gyroid structures was confirmed through variations in stress and strain concentrations, deformation behaviour, and Young’s modulus under different loading directions. Full article

(This article belongs to the Special Issue Recent Advances in 3D Printing Technologies in Bioengineering with Selected Papers from the 29th Congress of the European Society of Biomechanics (ESB 2024))

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22 pages, 6236 KiB

Open AccessArticle

An Experimental Investigation into the Enhancement of Surface Quality of Inconel 718 Through Axial Ultrasonic Vibration-Assisted Grinding in Dry and MQL Environments

by Sreethul Das, Pandivelan Chinnaiyan, Joel Jayaseelan, Jeyapandiarajan Paulchamy, Andre Batako and Ashwath Pazhani

J. Manuf. Mater. Process. 2024, 8(6), 255; https://doi.org/10.3390/jmmp8060255 - 13 Nov 2024

Viewed by 518

Abstract

Ultrasonic vibration-assisted grinding (UVAG) has proven to be beneficial for grinding difficult-to-machine materials. This work attempts to enhance the grinding performance of Inconel 718 through a comprehensive study of UVAG characteristics. Grinding experiments were performed in both dry and Minimum Quantity Lubrication (MQL) [...] Read more.

Ultrasonic vibration-assisted grinding (UVAG) has proven to be beneficial for grinding difficult-to-machine materials. This work attempts to enhance the grinding performance of Inconel 718 through a comprehensive study of UVAG characteristics. Grinding experiments were performed in both dry and Minimum Quantity Lubrication (MQL) environments, and assessment of the grinding forces, specific energy, residual stress, and surface topography was done. A substantial reduction of both surface roughness and grinding force components was observed in UVAG compared to conventional grinding (CG). Utilizing UVAG with MQL at the maximum vibration amplitude led to a 64% reduction in tangential grinding force and a 51% decrease in roughness parameter, R_a, when compared to CG conducted in a dry environment. The high-frequency indentations of the abrasives in UVAG generated compressive residual stresses on the ground surface. Surface parameters pointed to uniform texture and SEM images showed widening of abrasive grain tracks on the workpiece surface during UVAG. The utilization of UVAG under MQL produced a synergistic impact and resulted in the lowest grinding forces, specific energy, and optimal surface quality among all the grinding conditions investigated. Overall analysis of the results indicated that the axial configuration of the vibration set-up is favorable for UVAG, and the high-frequency periodic separation-cutting characteristic of the process improves lubricating efficiency and grinding performance. Full article

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11 pages, 4564 KiB

Open AccessArticle

Managing Residual Heat Effects in Femtosecond Laser Material Processing by Pulse-on-Demand Operation

by Jaka Petelin, Matevž Marš, Jaka Mur and Rok Petkovšek

J. Manuf. Mater. Process. 2024, 8(6), 254; https://doi.org/10.3390/jmmp8060254 - 12 Nov 2024

Viewed by 762

Abstract

Femtosecond laser processing combines highly accurate structuring with low residual heating of materials, low thermal damage, and nonlinear absorption processes, making it suitable for the machining of transparent brittle materials. However, with high average powers and laser pulse repetition rates, residual heating becomes [...] Read more.

Femtosecond laser processing combines highly accurate structuring with low residual heating of materials, low thermal damage, and nonlinear absorption processes, making it suitable for the machining of transparent brittle materials. However, with high average powers and laser pulse repetition rates, residual heating becomes relevant. Here, we present a study of the femtosecond laser pulse-on-demand operation regime, combined with regular scanners, aiming to improve throughput and quality of processing regardless of the scanner’s capabilities. We developed two methods to define the needed pulse-on-demand trigger sequences that compensate for the initial accelerating scanner movements. The effects of pulse-on-demand operation were studied in detail using direct process monitoring with a fast thermal camera and indirect process monitoring with optical and topographical surface imaging of final structures, both showing clear advantages of pulse-on-demand operation in precision, thermal effects, and structure shape control. The ability to compensate for irregular scanner movement is the basis for simplified, cheaper, and faster femtosecond laser processing of brittle and heat-susceptible materials. Full article

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J. Manuf. Mater. Process., Volume 8, Issue 6 (December 2024) – 48 articles

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