Additive manufacturing letters最新文献

英文中文

Columnar-to-equiaxed transitions in additively manufactured face-centered cubic multi-principal element alloys

IF 4.2 Q2 ENGINEERING, MANUFACTURING

Additive manufacturing letters

Pub Date : 2025-04-14 DOI: 10.1016/j.addlet.2025.100283

Mengyao Zheng , Yu Liao , Zheng Zhou , Hao Zhang , Chuanwei Li , Zhong Long , Jianfeng Gu

Columnar-to-equiaxed transition (CET) represents a critical microstructural characteristic in additively manufactured alloys. Precise control over CET is essential for achieving high-performance metallic components through additive manufacturing. In this study, two face-centered cubic multi-principal element alloys (MPEAs), namely CoCrNi and FeCoCrNi, were fabricated via laser directed energy deposition. The influence of process parameter and alloy composition on the CET of the two MPEAs was investigated. The results demonstrated that pronounced CET phenomena were observed in both MPEAs as the laser power increased and the scanning speed decreased. However, significant variations were noted in their CET parameters, equiaxed grain fraction, and crystallographic texture. Subsequently, the impact of process parameters on temperature gradient, solidification rate, and molten pool morphology was investigated via finite element modelling, revealing the formation mechanisms of the grain morphology and texture in additively manufactured CoCrNi and FeCoCrNi alloys. Additionally, the results of thermodynamic calculation revealed significant differences in the growth restriction factors between the two MPEAs, thereby explaining the distinct CET behaviors observed in the two MPEAs.

{"title":"Columnar-to-equiaxed transitions in additively manufactured face-centered cubic multi-principal element alloys","authors":"Mengyao Zheng , Yu Liao , Zheng Zhou , Hao Zhang , Chuanwei Li , Zhong Long , Jianfeng Gu","doi":"10.1016/j.addlet.2025.100283","DOIUrl":"10.1016/j.addlet.2025.100283","url":null,"abstract":"<div><div>Columnar-to-equiaxed transition (CET) represents a critical microstructural characteristic in additively manufactured alloys. Precise control over CET is essential for achieving high-performance metallic components through additive manufacturing. In this study, two face-centered cubic multi-principal element alloys (MPEAs), namely CoCrNi and FeCoCrNi, were fabricated via laser directed energy deposition. The influence of process parameter and alloy composition on the CET of the two MPEAs was investigated. The results demonstrated that pronounced CET phenomena were observed in both MPEAs as the laser power increased and the scanning speed decreased. However, significant variations were noted in their CET parameters, equiaxed grain fraction, and crystallographic texture. Subsequently, the impact of process parameters on temperature gradient, solidification rate, and molten pool morphology was investigated via finite element modelling, revealing the formation mechanisms of the grain morphology and texture in additively manufactured CoCrNi and FeCoCrNi alloys. Additionally, the results of thermodynamic calculation revealed significant differences in the growth restriction factors between the two MPEAs, thereby explaining the distinct CET behaviors observed in the two MPEAs.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"14 ","pages":"Article 100283"},"PeriodicalIF":4.2,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143859350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Material extrusion with integrated compression molding of NdFeB/SmFeN nylon bonded magnets using small- and large-scale pellet-based 3D-printers

IF 4.2 Q2 ENGINEERING, MANUFACTURING

Additive manufacturing letters

Pub Date : 2025-04-01 DOI: 10.1016/j.addlet.2025.100282

Kaustubh Mungale , Vipin Kumar , Mariappan Parans Paranthaman , Brian C. Sales , Harshida Parmar , Ikenna C. Nlebedim , Brittany Rodriguez , Uday Kumar Vaidya

High-density bonded rare-earth magnets are manufactured using pellet-fed additive manufacturing (AM)/material extrusion and an integrated additive manufacturing-compression molding (AM-CM) process. Neodymium iron boron – samarium iron nitride in polyamide 12 (NdFeB-SmFeN/PA12) of 93 % weight fraction (65 % volume fraction) are used for the study. The mechanical properties (tensile strength and modulus), magnetic properties (maximum energy density, coercivity, remanence) are reported. Manufacturing parameters such as layer height, barrel temperatures, screw speed and gantry feed rate are optimized to obtain the highest possible density of the magnets using a small-scale desktop material extrusion printer. Large scale integrated additive manufacturing-compression molding (AM-CM) is then utilized to increase the density of the magnets by reducing porosity defects common in the material extrusion process. The density of as-printed magnets was 5.2 g/cm³ with a BH_max value of 124.14 kJ/m³, tensile strength of 20 MPa and a modulus of 2 GPa. AM-CM increased the density of the compound by 5.5 % (5.49 g/cm³). The reduction in porosity was confirmed using X-ray tomography (XCT). Improvement in mechanical strength of the material was also observed, with an increase in tensile strength of 25 % (25.09 MPa) and increase in tensile modulus of 275 % (5.49 GPa). Scanning electron microscopy showed increased particle-matrix adhesion with the integrated AM-CM process.

{"title":"Material extrusion with integrated compression molding of NdFeB/SmFeN nylon bonded magnets using small- and large-scale pellet-based 3D-printers","authors":"Kaustubh Mungale , Vipin Kumar , Mariappan Parans Paranthaman , Brian C. Sales , Harshida Parmar , Ikenna C. Nlebedim , Brittany Rodriguez , Uday Kumar Vaidya","doi":"10.1016/j.addlet.2025.100282","DOIUrl":"10.1016/j.addlet.2025.100282","url":null,"abstract":"<div><div>High-density bonded rare-earth magnets are manufactured using pellet-fed additive manufacturing (AM)/material extrusion and an integrated additive manufacturing-compression molding (AM-CM) process. Neodymium iron boron – samarium iron nitride in polyamide 12 (NdFeB-SmFeN/PA12) of 93 % weight fraction (65 % volume fraction) are used for the study. The mechanical properties (tensile strength and modulus), magnetic properties (maximum energy density, coercivity, remanence) are reported. Manufacturing parameters such as layer height, barrel temperatures, screw speed and gantry feed rate are optimized to obtain the highest possible density of the magnets using a small-scale desktop material extrusion printer. Large scale integrated additive manufacturing-compression molding (AM-CM) is then utilized to increase the density of the magnets by reducing porosity defects common in the material extrusion process. The density of as-printed magnets was 5.2 g/cm<sup>3</sup> with a <em>BH<sub>max</sub></em> value of 124.14 kJ/m<sup>3</sup>, tensile strength of 20 MPa and a modulus of 2 GPa. AM-CM increased the density of the compound by 5.5 % (5.49 g/cm<sup>3</sup>). The reduction in porosity was confirmed using X-ray tomography (XCT). Improvement in mechanical strength of the material was also observed, with an increase in tensile strength of 25 % (25.09 MPa) and increase in tensile modulus of 275 % (5.49 GPa). Scanning electron microscopy showed increased particle-matrix adhesion with the integrated AM-CM process.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"13 ","pages":"Article 100282"},"PeriodicalIF":4.2,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143838686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

On cyber sabotage risks in automated manufacturing of advanced composites

IF 4.2 Q2 ENGINEERING, MANUFACTURING

Additive manufacturing letters

Pub Date : 2025-04-01 DOI: 10.1016/j.addlet.2025.100280

Saral Mittal , Hammond Pearce , Mark Yampolskiy , Ebrahim Oromiehie , B. Gangadhara Prusty

Recent advancements in the manufacturing of layered composite structures have seen the deployment of automated control systems, with computers used for both design protocols and control of manufacturing processes. However, as digitisation and computerisation of composites manufacturing advances, so too grows the potential exposure to cyber-attacks. Given that large manufacturing companies, government organisations, and defence agencies are increasingly utilising parts made out of fibre-reinforced composite materials, this security exposure must be acknowledged and managed carefully.

From other computerised manufacturing domains, we know that adversaries may aim to steal technical data such as digital design files (for example, for espionage or to infringe on Intellectual Property, IP) or to sabotage manufactured parts. Both can have consequences reaching far beyond immediate financial or physical damage. While it can be assumed that the adversarial goals are similar for composites manufacturing, the attack methods have not been explored or studied yet. This paper seeks to address this gap in part, by providing the first holistic security analysis of potential sabotage attacks in automated composites manufacturing using modern equipment. This security analysis provides a framework for composite manufacturers to identify vulnerabilities in their production workflows that are susceptible to cyber-attacks, while also providing opportunity to design customised countermeasures to strengthen the security of their automated manufacturing processes.

{"title":"On cyber sabotage risks in automated manufacturing of advanced composites","authors":"Saral Mittal , Hammond Pearce , Mark Yampolskiy , Ebrahim Oromiehie , B. Gangadhara Prusty","doi":"10.1016/j.addlet.2025.100280","DOIUrl":"10.1016/j.addlet.2025.100280","url":null,"abstract":"<div><div>Recent advancements in the manufacturing of layered composite structures have seen the deployment of automated control systems, with computers used for both design protocols and control of manufacturing processes. However, as digitisation and computerisation of composites manufacturing advances, so too grows the potential exposure to cyber-attacks. Given that large manufacturing companies, government organisations, and defence agencies are increasingly utilising parts made out of fibre-reinforced composite materials, this security exposure must be acknowledged and managed carefully.</div><div>From other computerised manufacturing domains, we know that adversaries may aim to steal technical data such as digital design files (for example, for espionage or to infringe on Intellectual Property, IP) or to sabotage manufactured parts. Both can have consequences reaching far beyond immediate financial or physical damage. While it can be assumed that the adversarial goals are similar for composites manufacturing, the attack methods have not been explored or studied yet. This paper seeks to address this gap in part, by providing the first holistic security analysis of potential sabotage attacks in automated composites manufacturing using modern equipment. This security analysis provides a framework for composite manufacturers to identify vulnerabilities in their production workflows that are susceptible to cyber-attacks, while also providing opportunity to design customised countermeasures to strengthen the security of their automated manufacturing processes.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"13 ","pages":"Article 100280"},"PeriodicalIF":4.2,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143823526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Simultaneously improving strength and corrosion resistance of additively manufactured Mg-Gd-Zr alloy by in-situ alloying with Al

IF 4.2 Q2 ENGINEERING, MANUFACTURING

Additive manufacturing letters

Pub Date : 2025-04-01 DOI: 10.1016/j.addlet.2025.100279

Ziyi Liu, Qingchen Deng, Yiwen Ding, Ziyan Li, Jiacheng Wang, Liming Peng

Additive manufacturing of magnesium (Mg) alloy components with intricate geometries via laser powder bed fusion (LPBF) offers significant advantages for lightweight engineering applications. However, as a commonly issue of Mg alloys, the corrosion resistance of LPBF-Mg alloys is even worse than their cast and deformed counterparts. In-situ alloying provides a rapid pathway for composition modification tailored for the LPBF process. In this study, aluminum (Al) is introduced through in-situ alloying to prepare Mg-10Gd-xAl-Zr (GA10xK, x = 0.5, 1, 2 wt. %) alloys using blended Mg-10Gd-Zr and Mg-15Al powders. By employing a lower scanning speed during LPBF, a uniform distribution of Al throughout the as-built components is achieved. The increase in Al content leads to the progressive enhancement in grain refinement and the transformation of secondary phases from Mg₃Gd to Al₂Gd with a significant reduction in size and a notable increase in number density. These microstructural transformations yield a synchronous enhancement in strength and corrosion resistance with increasing Al content. The yield strength and ultimate tensile strength of the GA102K alloy reach 328 MPa and 350 MPa, respectively, with a minimized corrosion rate of 0.787 mm/yr., surpassing the mechanical and corrosion performance of both LPBF and semi-continuous cast G10K alloys.

{"title":"Simultaneously improving strength and corrosion resistance of additively manufactured Mg-Gd-Zr alloy by in-situ alloying with Al","authors":"Ziyi Liu, Qingchen Deng, Yiwen Ding, Ziyan Li, Jiacheng Wang, Liming Peng","doi":"10.1016/j.addlet.2025.100279","DOIUrl":"10.1016/j.addlet.2025.100279","url":null,"abstract":"<div><div>Additive manufacturing of magnesium (Mg) alloy components with intricate geometries via laser powder bed fusion (LPBF) offers significant advantages for lightweight engineering applications. However, as a commonly issue of Mg alloys, the corrosion resistance of LPBF-Mg alloys is even worse than their cast and deformed counterparts. In-situ alloying provides a rapid pathway for composition modification tailored for the LPBF process. In this study, aluminum (Al) is introduced through in-situ alloying to prepare Mg-10Gd-xAl-Zr (GA10xK, <em>x</em> = 0.5, 1, 2 wt. %) alloys using blended Mg-10Gd-Zr and Mg-15Al powders. By employing a lower scanning speed during LPBF, a uniform distribution of Al throughout the as-built components is achieved. The increase in Al content leads to the progressive enhancement in grain refinement and the transformation of secondary phases from Mg<sub>3</sub>Gd to Al<sub>2</sub>Gd with a significant reduction in size and a notable increase in number density. These microstructural transformations yield a synchronous enhancement in strength and corrosion resistance with increasing Al content. The yield strength and ultimate tensile strength of the GA102K alloy reach 328 MPa and 350 MPa, respectively, with a minimized corrosion rate of 0.787 mm/yr., surpassing the mechanical and corrosion performance of both LPBF and semi-continuous cast G10K alloys.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"13 ","pages":"Article 100279"},"PeriodicalIF":4.2,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143739518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhanced superelasticity and notable elastocaloric effect of Cu71Al17.5Mn11.5 shape memory alloys by laser-based powder bed fusion

IF 4.2 Q2 ENGINEERING, MANUFACTURING

Additive manufacturing letters

Pub Date : 2025-04-01 DOI: 10.1016/j.addlet.2025.100281

Xiang Li , Zeming Fan , Qijie Zhai , Gang Wang , Xiang Lu , Hanyang Qian , Rui Cai , Daqiang Jiang , Jian Liu

Cu-based shape memory alloys (SMAs) with highly oriented columnar grains and high densities are promising candidates for solid-state refrigeration. In this work, the Cu₇₁Al_17.5Mn_11.5 alloys with a strong 〈001〉 texture columnar grains and a high relative density were fabricated using laser-based powder bed fusion of metals (PBF-LB/M) technique. The Cu₇₁Al_17.5Mn_11.5 alloys exhibited enhanced superelasticity, with a superelastic strain of 6.2 %. A maximum recoverable strain of 8.5 % was achieved under 9 % compressive loading, which includes both superelastic and elastic strain components. Additionally, a notable elastocaloric temperature change of 8.0 K was achieved upon fast unloading under adiabatic conditions. The phase transformation behavior has been systematically investigated by the digital image correlation (DIC) and the transmission wide-angle X-ray diffraction measurements. The current results suggest that the additive manufacturing could be a promising route for near-net-shape high-performance Cu-based elastocaloric refrigerants.

{"title":"Enhanced superelasticity and notable elastocaloric effect of Cu71Al17.5Mn11.5 shape memory alloys by laser-based powder bed fusion","authors":"Xiang Li , Zeming Fan , Qijie Zhai , Gang Wang , Xiang Lu , Hanyang Qian , Rui Cai , Daqiang Jiang , Jian Liu","doi":"10.1016/j.addlet.2025.100281","DOIUrl":"10.1016/j.addlet.2025.100281","url":null,"abstract":"<div><div>Cu-based shape memory alloys (SMAs) with highly oriented columnar grains and high densities are promising candidates for solid-state refrigeration. In this work, the Cu<sub>71</sub>Al<sub>17.5</sub>Mn<sub>11.5</sub> alloys with a strong 〈001〉 texture columnar grains and a high relative density were fabricated using laser-based powder bed fusion of metals (PBF-LB/M) technique. The Cu<sub>71</sub>Al<sub>17.5</sub>Mn<sub>11.5</sub> alloys exhibited enhanced superelasticity, with a superelastic strain of 6.2 %. A maximum recoverable strain of 8.5 % was achieved under 9 % compressive loading, which includes both superelastic and elastic strain components. Additionally, a notable elastocaloric temperature change of 8.0 K was achieved upon fast unloading under adiabatic conditions. The phase transformation behavior has been systematically investigated by the digital image correlation (DIC) and the transmission wide-angle X-ray diffraction measurements. The current results suggest that the additive manufacturing could be a promising route for near-net-shape high-performance Cu-based elastocaloric refrigerants.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"13 ","pages":"Article 100281"},"PeriodicalIF":4.2,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143828193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Enhancing dental model accuracy through optimized vat photopolymerization additive manufacturing parameters

IF 4.2 Q2 ENGINEERING, MANUFACTURING

Additive manufacturing letters

Pub Date : 2025-03-15 DOI: 10.1016/j.addlet.2025.100278

Clément Tien , Camille Jean , Lucas Poupaud , Floriane Laverne , Frédéric Segonds

This study investigates the key additive manufacturing (AM) process parameters that influence the dimensional accuracy of dental models produced using the vat photopolymerization Digital Light Processing (DLP) technology. By applying the Taguchi method, 7AM process factors were analyzed. A standardized post-processing protocol was used to maintain consistency, allowing a focused assessment of the printing parameters. Dimensional deviations were analyzed using 3D scanning and point cloud comparison software, with particular attention to reducing warping and shrinkage. The results identified layer thickness, projector power, exposure energy, and vat temperature as the key AM factors affecting the accuracy of the final model. These findings highlight the importance of optimizing these parameters to achieve high-quality dental models, contributing to future advancements in precision and efficiency. Further research is recommended to determine optimal settings for different resins and more complex dental structures.

引用次数: 0

Qualification of additively manufactured polymer fluid manifolds for life-detection instruments

IF 4.2 Q2 ENGINEERING, MANUFACTURING

Additive manufacturing letters

Pub Date : 2025-03-04 DOI: 10.1016/j.addlet.2025.100277

Theresa Juarez, Nathan J. Oborny, Andrew Berg, Aaron C. Noell

The development of autonomous life detection instruments is being driven by the advancement of multiple space exploration missions to investigate the subsurface oceans of icy worlds, particularly Titan, Enceladus, and Europa. A fundamental feature of this type of instrument is a compact, reliable, and chemically inert internal liquid transport network. Additively manufactured (AM) custom liquid manifolds produced via vat photopolymerization (VPP) methods can meet these requirements. However, before these materials can be considered, basic spaceflight requirements, qualification for flight worthiness and functionality must be addressed. In this study, mechanical properties, outgassing behavior, polymeric characteristics, and chemical compatibility are assessed for select commercially available AM polymers. The results indicate basic materials qualification requirements are met, including sufficiently characterized mechanical properties, the identification of a bakeout protocol for reduced outgassing to meet NASA standards, and chemical compatibility with liquids and reagents used in candidate instrumentation under development for life detection missions.

{"title":"Qualification of additively manufactured polymer fluid manifolds for life-detection instruments","authors":"Theresa Juarez, Nathan J. Oborny, Andrew Berg, Aaron C. Noell","doi":"10.1016/j.addlet.2025.100277","DOIUrl":"10.1016/j.addlet.2025.100277","url":null,"abstract":"<div><div>The development of autonomous life detection instruments is being driven by the advancement of multiple space exploration missions to investigate the subsurface oceans of icy worlds, particularly Titan, Enceladus, and Europa. A fundamental feature of this type of instrument is a compact, reliable, and chemically inert internal liquid transport network. Additively manufactured (AM) custom liquid manifolds produced via vat photopolymerization (VPP) methods can meet these requirements. However, before these materials can be considered, basic spaceflight requirements, qualification for flight worthiness and functionality must be addressed. In this study, mechanical properties, outgassing behavior, polymeric characteristics, and chemical compatibility are assessed for select commercially available AM polymers. The results indicate basic materials qualification requirements are met, including sufficiently characterized mechanical properties, the identification of a bakeout protocol for reduced outgassing to meet NASA standards, and chemical compatibility with liquids and reagents used in candidate instrumentation under development for life detection missions.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"13 ","pages":"Article 100277"},"PeriodicalIF":4.2,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143706047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of raster orientation on large-scale robotic 3D printing of short carbon fiber-reinforced PLA composites

IF 4.2 Q2 ENGINEERING, MANUFACTURING

Additive manufacturing letters

Pub Date : 2025-02-18 DOI: 10.1016/j.addlet.2025.100276

E. Baharlou , J. Ma

Additive manufacturing in building construction can be extended for mass customization of building components or even complex mold making. This study examines the process parameters of raster orientation of short carbon fiber-reinforced polylactic acid (SCF-PLA) and neat PLA in large-scale 3D printing. Three raster orientations—unidirectional, cross-ply, and quasi-isotropic layups—were printed using a pellet extruder assembled on an industrial robotic arm. Tensile and flexural tests were conducted to characterize the differences between SCF-PLA and neat PLA across all raster orientations. This study shows that neat PLA has higher tensile strength compared to SCF-PLA, and quasi-isotropic orientation can improve the week mechanical properties of both SCF-PLA and PLA. This research highlights the interface bonding challenges encountered with larger 3D printed filaments, which result in more significant pores. Furthermore, any factor that modifies rheological properties of the filament, such as carbon filling, can lead to a higher likelihood of material defects. To understand this discrepancy, microstructure analyses were conducted on intact and fractured 3D printed samples, including the analysis of micro voids, interlayer voids, and bonding between SCF and the PLA matrix. This suggests that the effects of quasi-isotropic layups can be applied to enhance 3D print large-scale polymer-based building components.

{"title":"Effect of raster orientation on large-scale robotic 3D printing of short carbon fiber-reinforced PLA composites","authors":"E. Baharlou , J. Ma","doi":"10.1016/j.addlet.2025.100276","DOIUrl":"10.1016/j.addlet.2025.100276","url":null,"abstract":"<div><div>Additive manufacturing in building construction can be extended for mass customization of building components or even complex mold making. This study examines the process parameters of raster orientation of short carbon fiber-reinforced polylactic acid (SCF-PLA) and neat PLA in large-scale 3D printing. Three raster orientations—unidirectional, cross-ply, and quasi-isotropic layups—were printed using a pellet extruder assembled on an industrial robotic arm. Tensile and flexural tests were conducted to characterize the differences between SCF-PLA and neat PLA across all raster orientations. This study shows that neat PLA has higher tensile strength compared to SCF-PLA, and quasi-isotropic orientation can improve the week mechanical properties of both SCF-PLA and PLA. This research highlights the interface bonding challenges encountered with larger 3D printed filaments, which result in more significant pores. Furthermore, any factor that modifies rheological properties of the filament, such as carbon filling, can lead to a higher likelihood of material defects. To understand this discrepancy, microstructure analyses were conducted on intact and fractured 3D printed samples, including the analysis of micro voids, interlayer voids, and bonding between SCF and the PLA matrix. This suggests that the effects of quasi-isotropic layups can be applied to enhance 3D print large-scale polymer-based building components.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"13 ","pages":"Article 100276"},"PeriodicalIF":4.2,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Process screening in additive manufacturing: Detection of keyhole mode using surface topography and machine learning

IF 4.2 Q2 ENGINEERING, MANUFACTURING

Additive manufacturing letters

Pub Date : 2025-02-17 DOI: 10.1016/j.addlet.2025.100275

Mingzhang Yang, Ali Rezaei, Mihaela Vlasea

Screening of defective additive manufactured (AM) parts is crucial for ensuring process consistency and part reliability, yet common microstructural inspection methods can be time-consuming or destructive. This study explores how surface analysis combined with machine learning (ML) algorithms can effectively infer the microstructure of laser powder bed fusion (LPBF) parts. As a case study, non-spherical ZrH₂ nanoparticle-enhanced AA7075 aluminum powders was fabricated using 60 different LPBF recipes. ML classification models were then employed to link side-surface topographical features to keyhole melting occurring within the parts. Among the tested ML models, random forest (RF) achieving a testing accuracy of 95 % and an F1-score of 0.98, outperforming both the neural network (NN) and support vector machine (SVM) models. To enhance the interpretability of the ML model, the RF model was leveraged to identify the hierarchical importance of surface features associated with keyhole melting mode. This resulted in the development of keyhole-probability maps based on superficial surface parameters, providing engineers with an effective and easy-to-use tool for screening keyhole mode parts. While further validation is needed, the proposed strategy lays a foundation for leveraging surface topography to infer microstructural features and adapting the method to different material systems.

筛查有缺陷的增材制造（AM）零件对于确保工艺一致性和零件可靠性至关重要，但常见的微观结构检测方法可能会耗费大量时间或具有破坏性。本研究探讨了表面分析与机器学习（ML）算法相结合如何有效地推断激光粉末床熔融（LPBF）零件的微观结构。作为案例研究，使用 60 种不同的 LPBF 配方制造了非球形 ZrH₂ 纳米粒子增强 AA7075 铝粉。然后采用 ML 分类模型将侧面表面地形特征与零件内部发生的锁孔熔化联系起来。在测试的 ML 模型中，随机森林（RF）的测试准确率达到 95%，F1 分数为 0.98，优于神经网络（NN）和支持向量机（SVM）模型。为了提高 ML 模型的可解释性，利用 RF 模型识别了与钥匙孔熔化模式相关的表面特征的层次重要性。这样就开发出了基于表面参数的锁孔概率图，为工程师筛选锁孔模式零件提供了有效且易于使用的工具。虽然还需要进一步验证，但所提出的策略为利用表面形貌推断微观结构特征以及将该方法适用于不同材料系统奠定了基础。

{"title":"Process screening in additive manufacturing: Detection of keyhole mode using surface topography and machine learning","authors":"Mingzhang Yang, Ali Rezaei, Mihaela Vlasea","doi":"10.1016/j.addlet.2025.100275","DOIUrl":"10.1016/j.addlet.2025.100275","url":null,"abstract":"<div><div>Screening of defective additive manufactured (AM) parts is crucial for ensuring process consistency and part reliability, yet common microstructural inspection methods can be time-consuming or destructive. This study explores how surface analysis combined with machine learning (ML) algorithms can effectively infer the microstructure of laser powder bed fusion (LPBF) parts. As a case study, non-spherical ZrH₂ nanoparticle-enhanced AA7075 aluminum powders was fabricated using 60 different LPBF recipes. ML classification models were then employed to link side-surface topographical features to keyhole melting occurring within the parts. Among the tested ML models, random forest (RF) achieving a testing accuracy of 95 % and an F1-score of 0.98, outperforming both the neural network (NN) and support vector machine (SVM) models. To enhance the interpretability of the ML model, the RF model was leveraged to identify the hierarchical importance of surface features associated with keyhole melting mode. This resulted in the development of keyhole-probability maps based on superficial surface parameters, providing engineers with an effective and easy-to-use tool for screening keyhole mode parts. While further validation is needed, the proposed strategy lays a foundation for leveraging surface topography to infer microstructural features and adapting the method to different material systems.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"13 ","pages":"Article 100275"},"PeriodicalIF":4.2,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143445387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of the laser strategy on bi-metallic interfaces printed via multi-material laser-based powder bed fusion

IF 4.2 Q2 ENGINEERING, MANUFACTURING

Additive manufacturing letters

Pub Date : 2025-02-10 DOI: 10.1016/j.addlet.2025.100274

Isabel B. Prestes, Eric A. Jägle

Metallic Multi-material Additive Manufacturing (MMAM) is an emerging research topic, with potential applications in heat exchangers, metamaterials and satellite components. In recent years, new multi-material laser powder bed fusion (PBF-LB) techniques have been developed. However, processing challenges may arise, since materials with dissimilar properties are mixed at the interfaces, which might lead to defects such as cracks. This work aims to investigate the influence of different laser scan strategies to achieve sound interfaces with different material mixing gradients. The samples, made of Inconel 718 and Invar were deposited by the patterning drums technique and were analyzed by means of optical microscopy and energy-dispersive X-ray spectroscopy (EDS) mappings and line scans. The orientation in which melt pools cross the material interface plays an important role in mixing the materials. Different orientations in subsequent layers create a certain “jagged” pattern of mixing at the interface. Sigmoid functions of Boltzmann fitted to the line scans show a significant slope steepness increase – up to 75 % – in the element count from double scan to single scan, suggesting a stronger material mixing. The double scan strategy leads to porosity at the interface and thus should be avoided. The remelt at the interface partially healed defects such as cracks but does not seem to influence the mixing width at the interface. These findings give general guidance for selecting scan strategies in MMAM depending on the desired mixing pattern at the material interface.

{"title":"Influence of the laser strategy on bi-metallic interfaces printed via multi-material laser-based powder bed fusion","authors":"Isabel B. Prestes, Eric A. Jägle","doi":"10.1016/j.addlet.2025.100274","DOIUrl":"10.1016/j.addlet.2025.100274","url":null,"abstract":"<div><div>Metallic Multi-material Additive Manufacturing (MMAM) is an emerging research topic, with potential applications in heat exchangers, metamaterials and satellite components. In recent years, new multi-material laser powder bed fusion (PBF-LB) techniques have been developed. However, processing challenges may arise, since materials with dissimilar properties are mixed at the interfaces, which might lead to defects such as cracks. This work aims to investigate the influence of different laser scan strategies to achieve sound interfaces with different material mixing gradients. The samples, made of Inconel 718 and Invar were deposited by the patterning drums technique and were analyzed by means of optical microscopy and energy-dispersive X-ray spectroscopy (EDS) mappings and line scans. The orientation in which melt pools cross the material interface plays an important role in mixing the materials. Different orientations in subsequent layers create a certain “jagged” pattern of mixing at the interface. Sigmoid functions of Boltzmann fitted to the line scans show a significant slope steepness increase – up to 75 % – in the element count from double scan to single scan, suggesting a stronger material mixing. The double scan strategy leads to porosity at the interface and thus should be avoided. The remelt at the interface partially healed defects such as cracks but does not seem to influence the mixing width at the interface. These findings give general guidance for selecting scan strategies in MMAM depending on the desired mixing pattern at the material interface.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"13 ","pages":"Article 100274"},"PeriodicalIF":4.2,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

下一页尾页

类型

全部化学•材料生命科学医学物理工程技术环境•农林材料科学地球科学法学管理学化学环境科学与生态学计算机科学教育学经济学农林科学人文科学生物学数学物理与天体物理心理学综合性期刊其他工业工程理学历史学农学文学信息工程

数据库

全部 ACS Publications Elsevier ieeexplore Springer The Royal Society of Chemistry Wiley

期刊

Additive manufacturing letters

全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.

﹀