Pub Date : 2025-01-25DOI: 10.1016/j.addma.2024.104624
M. Zawadzki , S. Kowalczyk , K. Zawada , M. Szewczyk-Łagodzińska , A. Plichta
Reactive material jetting utilizes droplets of reactive inks which cure on mixing. In this study, the process is carried out by in-air collision and coalescence of the jetted droplets and subsequent deposition of a combined droplet onto the build surface. Thereby, precise volumes of droplets can be mixed ensuring stoichiometric proportions to produce and pattern materials in a single step. A series of reactive inks based on urea/urethane systems were developed. Materials with different properties were obtained ranging from tough (E = 107 MPa, U = 14 MPa, ε(U) = 33 %) to brittle (E = 47 MPa, U = 4.4 MPa, ε(U) = 9.2 %) and to elastic (E = 12 MPa, U = 5.6 MPa, ε(U) = 915 %) (E = 24 MPa, U = 4.0, ε(U) = 350 %). Obtained data were correlated with multilinear equations or group contribution models. The best fitting was obtained for a group contribution model based on the produced material molar group contributions. The obtained data were discussed based on the fitted model. This simple model shows good interpolation agreement, indicating that it could be used to predict compositions of reactive inks to produce materials of desired properties.
{"title":"Development of urea-urethane-based binary inks for reactive material jetting system","authors":"M. Zawadzki , S. Kowalczyk , K. Zawada , M. Szewczyk-Łagodzińska , A. Plichta","doi":"10.1016/j.addma.2024.104624","DOIUrl":"10.1016/j.addma.2024.104624","url":null,"abstract":"<div><div>Reactive material jetting utilizes droplets of reactive inks which cure on mixing. In this study, the process is carried out by in-air collision and coalescence of the jetted droplets and subsequent deposition of a combined droplet onto the build surface. Thereby, precise volumes of droplets can be mixed ensuring stoichiometric proportions to produce and pattern materials in a single step. A series of reactive inks based on urea/urethane systems were developed. Materials with different properties were obtained ranging from tough (<em>E</em> = 107 MPa, <em>U</em> = 14 MPa, ε(<em>U</em>) = 33 %) to brittle (<em>E</em> = 47 MPa, <em>U</em> = 4.4 MPa, ε(<em>U</em>) = 9.2 %) and to elastic (<em>E</em> = 12 MPa, <em>U</em> = 5.6 MPa, ε(<em>U</em>) = 915 %) (<em>E</em> = 24 MPa, <em>U</em> = 4.0, ε(<em>U</em>) = 350 %). Obtained data were correlated with multilinear equations or group contribution models. The best fitting was obtained for a group contribution model based on the produced material molar group contributions. The obtained data were discussed based on the fitted model. This simple model shows good interpolation agreement, indicating that it could be used to predict compositions of reactive inks to produce materials of desired properties.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"98 ","pages":"Article 104624"},"PeriodicalIF":10.3,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143103848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-25DOI: 10.1016/j.addma.2025.104649
Xianyue Liu , Yuelan Di , Gang Wang , Qingyao Yuan , Yiming Rong
Hydrogen porosity is one of the common defects in the additive manufacturing of aluminum alloys. The presence of many pores initiates fracture cracks, reducing the strength and ductility of the materials. Understanding the evolution of hydrogen pores will be more conducive to controlling pores. In this study, micro X-ray computed tomography (μ-XCT) was employed to characterize the pore distribution along layers, and a high-fidelity multiphase flow model was developed to investigate the thermal-flow dynamics of hydrogen bubbles in coaxial laser-wire directed energy deposition. The model simulated bubble behaviors including bubble escape, coalescence, and capture. The simulations agreed well with the experimental results on the profile of the single track and pore amount in different layers. Pore formation depended on both melt flow and solidification rate. The criterion of bubble capture was proposed that the local solidification rate was larger than the bubble velocity. The impact of wire feeding on the molten pool caused strong melt flow at the top of the molten pool, and pores were not easy to form. The low-speed region appeared at the lower middle of the molten pool due to a recirculation pair, where hydrogen bubbles were likely to be captured with a large solidification rate. Heat accumulation during multilayer deposition altered the solidification characteristics, leading to an increase followed by a decrease in pore amount along the deposition direction. The hydrogen pores formed at the interface between columnar and equiaxed grains due to a high solidification rate in the region where the columnar-equiaxed transition occurred. Based on the experimental and simulation results, the evolution of grain morphology and hydrogen pores in multilayer deposition was reconstructed.
{"title":"The thermal-flow dynamics of hydrogen bubbles in coaxial laser wire directed energy deposition of Al-Mg-Sc alloy","authors":"Xianyue Liu , Yuelan Di , Gang Wang , Qingyao Yuan , Yiming Rong","doi":"10.1016/j.addma.2025.104649","DOIUrl":"10.1016/j.addma.2025.104649","url":null,"abstract":"<div><div>Hydrogen porosity is one of the common defects in the additive manufacturing of aluminum alloys. The presence of many pores initiates fracture cracks, reducing the strength and ductility of the materials. Understanding the evolution of hydrogen pores will be more conducive to controlling pores. In this study, micro X-ray computed tomography (μ-XCT) was employed to characterize the pore distribution along layers, and a high-fidelity multiphase flow model was developed to investigate the thermal-flow dynamics of hydrogen bubbles in coaxial laser-wire directed energy deposition. The model simulated bubble behaviors including bubble escape, coalescence, and capture. The simulations agreed well with the experimental results on the profile of the single track and pore amount in different layers. Pore formation depended on both melt flow and solidification rate. The criterion of bubble capture was proposed that the local solidification rate was larger than the bubble velocity. The impact of wire feeding on the molten pool caused strong melt flow at the top of the molten pool, and pores were not easy to form. The low-speed region appeared at the lower middle of the molten pool due to a recirculation pair, where hydrogen bubbles were likely to be captured with a large solidification rate. Heat accumulation during multilayer deposition altered the solidification characteristics, leading to an increase followed by a decrease in pore amount along the deposition direction. The hydrogen pores formed at the interface between columnar and equiaxed grains due to a high solidification rate in the region where the columnar-equiaxed transition occurred. Based on the experimental and simulation results, the evolution of grain morphology and hydrogen pores in multilayer deposition was reconstructed.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"98 ","pages":"Article 104649"},"PeriodicalIF":10.3,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143104525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-25DOI: 10.1016/j.addma.2024.104633
Yasuhiro Tasaka, Ryosuke Matsuzaki
Crystals known as transcrystals (TC) are formed near the carbon fibers of carbon-fiber-reinforced thermoplastics (CFRTPs). This study examined the crystallization behavior of 3D-printed resins associated with fibers under varying molding conditions using carbon fiber/polyphenylene-sulfide (CF/PPS) filaments. As the nozzle temperature increased, TC thickness increased linearly. In addition, the shear force during 3D printing likely facilitated the formation of TC at a temperature close to the melting point, which was not observed in previous studies. A high TC thickness value resulted in high interlaminar strength, which caused fiber fracture. The crystal structure of TC was confirmed at the fiber fracture site, presumably because of an increase in the interfacial strength of TC. In addition, the micro-Vickers test demonstrated that the hardness of the resin near the fibers with the TC was approximately twice that without the TC. This study applied TC to CFRTP 3D printing and proposed a new approach for improving interfacial strength.
{"title":"Crystallization behavior of thermoplastic resins near fibers and the influence of molding conditions during carbon fiber composite 3D printing","authors":"Yasuhiro Tasaka, Ryosuke Matsuzaki","doi":"10.1016/j.addma.2024.104633","DOIUrl":"10.1016/j.addma.2024.104633","url":null,"abstract":"<div><div>Crystals known as transcrystals (TC) are formed near the carbon fibers of carbon-fiber-reinforced thermoplastics (CFRTPs). This study examined the crystallization behavior of 3D-printed resins associated with fibers under varying molding conditions using carbon fiber/polyphenylene-sulfide (CF/PPS) filaments. As the nozzle temperature increased, TC thickness increased linearly. In addition, the shear force during 3D printing likely facilitated the formation of TC at a temperature close to the melting point, which was not observed in previous studies. A high TC thickness value resulted in high interlaminar strength, which caused fiber fracture. The crystal structure of TC was confirmed at the fiber fracture site, presumably because of an increase in the interfacial strength of TC. In addition, the micro-Vickers test demonstrated that the hardness of the resin near the fibers with the TC was approximately twice that without the TC. This study applied TC to CFRTP 3D printing and proposed a new approach for improving interfacial strength.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"98 ","pages":"Article 104633"},"PeriodicalIF":10.3,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143172254","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-21DOI: 10.1016/j.addma.2025.104666
Ling-Feng Yang, Xiao-Shan Zhang, Xin-Yue Huang, Jie Chen, Yao-Feng Mao, Jian Wang, Wei Huang, Fu-De Nie, Jun Wang
The limited mechanical properties of highly particle-filled polymer composites significantly hinder their practical application. Inspired by the Bouligand structure in the dactyl club of mantis shrimp, carbon fibers are implanted in a stereotactic manner in these composites to create a Bouligand structure with a controllable twisted angle, thereby improving their mechanical properties. This composite material, featuring a 15° twisted Bouligand configuration, demonstrates remarkable toughness and strength. It exhibits a maximum toughness of 32 kJ/m3, an ideal flexural strength of 8.86 MPa, and a flexural toughness of 472 kJ/m3, representing enhancements of 170 %, 64 %, and 300 % compared to the raw composite, respectively. Additionally, the Bouligand structure improves the peak stress and total energy absorption (∼10.08 MJ/m3) of each composite in the impact tests. Furthermore, the crack morphology and finite element (FE) simulations reveal a synergistic strengthening mechanism involving effective stress transfer, and twisted crack extension mechanism. This study indicates that constructing biomimetic Bouligand structure is a promising strategy for reinforcing the highly particle-filled polymer composites.
{"title":"Biomimetic Bouligand structure assisted mechanical enhancement of highly particle-filled polymer composites","authors":"Ling-Feng Yang, Xiao-Shan Zhang, Xin-Yue Huang, Jie Chen, Yao-Feng Mao, Jian Wang, Wei Huang, Fu-De Nie, Jun Wang","doi":"10.1016/j.addma.2025.104666","DOIUrl":"10.1016/j.addma.2025.104666","url":null,"abstract":"<div><div>The limited mechanical properties of highly particle-filled polymer composites significantly hinder their practical application. Inspired by the Bouligand structure in the dactyl club of mantis shrimp, carbon fibers are implanted in a stereotactic manner in these composites to create a Bouligand structure with a controllable twisted angle, thereby improving their mechanical properties. This composite material, featuring a 15° twisted Bouligand configuration, demonstrates remarkable toughness and strength. It exhibits a maximum toughness of 32 kJ/m<sup>3</sup>, an ideal flexural strength of 8.86 MPa, and a flexural toughness of 472 kJ/m<sup>3</sup>, representing enhancements of 170 %, 64 %, and 300 % compared to the raw composite, respectively. Additionally, the Bouligand structure improves the peak stress and total energy absorption (∼10.08 MJ/m<sup>3</sup>) of each composite in the impact tests. Furthermore, the crack morphology and finite element (FE) simulations reveal a synergistic strengthening mechanism involving effective stress transfer, and twisted crack extension mechanism. This study indicates that constructing biomimetic Bouligand structure is a promising strategy for reinforcing the highly particle-filled polymer composites.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"100 ","pages":"Article 104666"},"PeriodicalIF":10.3,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143270070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-05DOI: 10.1016/j.addma.2024.104606
Wanhyuk Chang , Kyung Ho Oh , Sung Min Kang, Jun Sung Hwang, Kyung Chan Min, Joon Hyung Shim
We report the fabrication of high-performance PrBa0.5Sr0.5Co1.5Fe0.5O5+δ (PBSCF) cathodes with optimized nanostructures achieved through the nano-engineering precision of piezoelectric inkjet printing (P-IJP) for protonic ceramic fuel cells (PCFCs). Compared to thermal inkjet printing (T-IJP), P-IJP produces smaller, more uniform droplets with stable printing performance, enabling precise control of both the cathode microstructure and the robust electrode-electrolyte interface. This structural tuning, characterized by uniformly distributed pores, is essential for creating active sites for electrochemical reactions in PCFCs. In our study, the precisely controlled cathode microstructure increases reactive sites for oxygen reduction reactions, enhancing charge transfer efficiency, while defect-free bonding across layers improves interfacial contact, as evidenced by significantly reduced polarization and ohmic resistance. These advancements culminated in a peak power density of 550 mW cm−2 at 500 °C, representing a substantial performance improvement over alternative processes, including T-IJP. Our findings highlight the potential of P-IJP to revolutionize PCFC fabrication and provide a versatile alternative to traditional manufacturing techniques for ceramic fuel cells and other energy-related materials.
{"title":"Nanostructural engineering of porous perovskite cathodes for high-performance protonic ceramic fuel-cells using piezoelectric inkjet-printing","authors":"Wanhyuk Chang , Kyung Ho Oh , Sung Min Kang, Jun Sung Hwang, Kyung Chan Min, Joon Hyung Shim","doi":"10.1016/j.addma.2024.104606","DOIUrl":"10.1016/j.addma.2024.104606","url":null,"abstract":"<div><div>We report the fabrication of high-performance PrBa<sub>0.5</sub>Sr<sub>0.5</sub>Co<sub>1.5</sub>Fe<sub>0.5</sub>O<sub>5+δ</sub> (PBSCF) cathodes with optimized nanostructures achieved through the nano-engineering precision of piezoelectric inkjet printing (P-IJP) for protonic ceramic fuel cells (PCFCs). Compared to thermal inkjet printing (T-IJP), P-IJP produces smaller, more uniform droplets with stable printing performance, enabling precise control of both the cathode microstructure and the robust electrode-electrolyte interface. This structural tuning, characterized by uniformly distributed pores, is essential for creating active sites for electrochemical reactions in PCFCs. In our study, the precisely controlled cathode microstructure increases reactive sites for oxygen reduction reactions, enhancing charge transfer efficiency, while defect-free bonding across layers improves interfacial contact, as evidenced by significantly reduced polarization and ohmic resistance. These advancements culminated in a peak power density of 550 mW cm<sup>−2</sup> at 500 °C, representing a substantial performance improvement over alternative processes, including T-IJP. Our findings highlight the potential of P-IJP to revolutionize PCFC fabrication and provide a versatile alternative to traditional manufacturing techniques for ceramic fuel cells and other energy-related materials.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"97 ","pages":"Article 104606"},"PeriodicalIF":10.3,"publicationDate":"2025-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143143275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, the microstructure and properties of a Mg-Li alloy prepared by cold metal transfer-based directed energy deposition using electric arc (CMT DED-arc) were investigated.The as-deposited alloy under different process parameters, as well as the alloy under various processing or heat treatment states, were evaluated. The results indicate that the designed alloy composition exhibits a wide process parameter window employing CMT DED-arc method. The optimal parameters were determined to be wire feed speed of 7 m/min and travel speed of 0.8 m/min, providing the best balance of mechanical properties, surface quality, and structural integrity. Variations in microstructure within different positions of as-deposited thin wall are ascribed to the effect of thermal cycle. The as-deposited alloy achieved excellent comprehensive performance (ultimate tensile strength (UTS)= 224 MPa, elongation= 13.2 %, Young’s modulus= 52 GPa, density= 1.539 g/cm³ ). Furthermore, the strength of deposition-solution-treated state exceed that of as-extruded state, reaching UTS of 287 MPa. This work provides insights into optimizing heat input and thermal cycle to improve performance of CMT DED-arc fabricated alloys.
{"title":"Ultra-light Mg-Li alloy with high modulus prepared by cold metal transfer-based directed energy deposition","authors":"Xinmiao Tao, Jiawei Sun, Yuchuan Huang, Jiaxin Yu, Youjie Guo, Yangyang Xu, Lingfan Yi, Guohua Wu, Wencai Liu","doi":"10.1016/j.addma.2024.104617","DOIUrl":"10.1016/j.addma.2024.104617","url":null,"abstract":"<div><div>In this study, the microstructure and properties of a Mg-Li alloy prepared by cold metal transfer-based directed energy deposition using electric arc (CMT DED-arc) were investigated.The as-deposited alloy under different process parameters, as well as the alloy under various processing or heat treatment states, were evaluated. The results indicate that the designed alloy composition exhibits a wide process parameter window employing CMT DED-arc method. The optimal parameters were determined to be wire feed speed of 7 m/min and travel speed of 0.8 m/min, providing the best balance of mechanical properties, surface quality, and structural integrity. Variations in microstructure within different positions of as-deposited thin wall are ascribed to the effect of thermal cycle. The as-deposited alloy achieved excellent comprehensive performance (ultimate tensile strength (UTS)= 224 MPa, elongation= 13.2 %, Young’s modulus= 52 GPa, density= 1.539 g/cm³ ). Furthermore, the strength of deposition-solution-treated state exceed that of as-extruded state, reaching UTS of 287 MPa. This work provides insights into optimizing heat input and thermal cycle to improve performance of CMT DED-arc fabricated alloys.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"97 ","pages":"Article 104617"},"PeriodicalIF":10.3,"publicationDate":"2025-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143143276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-05DOI: 10.1016/j.addma.2024.104600
Daniel June , Mehrdad Pourjam , Paul Gradl , Gabriel Demeneghi , Kavan Hazeli
This article investigates the evolution of mechanical properties in additively manufactured Haynes 214 alloy across temperatures from ambient to 950 °C, focusing on ductility loss and its relation to mechanical strength. Furthermore, it explores microscopic deformation mechanisms that influence mechanical behavior, such as the Portevin–Le Châtelier (PLC) effect and grain boundary cracking. This study reveals that up to 650 °C, strain hardening and the PLC effect dominate due to dislocation-solute interactions, while grain boundary cracking becomes prominent above 600 °C, coinciding with negligible slip activity within the grains. Specimens tested at ambient temperature show considerable texture evolution and grain distortion, whereas those tested at 650 °C and 870 °C show no evidence of texture evolution or grain distortion but instead grain boundary cracking. At temperatures above , the activation energy of the slip systems decreases significantly, allowing plastic deformation to be accommodated through a combination of Orowan dislocation bypassing mechanisms and grain boundary deformation and cracking, which partially restores ductility. Experiments with varying sample thicknesses (1 mm–2.5 mm) at ambient, 650 °C, and 870 °C reveal that thinner samples, with smaller grains and larger relative grain boundary areas, show distinct changes in serrated plastic flow, ductility loss, and strength degradation. Enhanced PLC formation in thinner samples compared to thicker ones at the same temperature, combined with reduced ductility, underscores the critical role of grain boundary deformation and cracking in ductility loss at elevated temperatures.
{"title":"High-temperature behavior of additively manufactured Haynes 214: Ductility loss and deformation mechanisms transition","authors":"Daniel June , Mehrdad Pourjam , Paul Gradl , Gabriel Demeneghi , Kavan Hazeli","doi":"10.1016/j.addma.2024.104600","DOIUrl":"10.1016/j.addma.2024.104600","url":null,"abstract":"<div><div>This article investigates the evolution of mechanical properties in additively manufactured Haynes 214 alloy across temperatures from ambient to 950 °C, focusing on ductility loss and its relation to mechanical strength. Furthermore, it explores microscopic deformation mechanisms that influence mechanical behavior, such as the Portevin–Le Châtelier (PLC) effect and grain boundary cracking. This study reveals that up to <span><math><mo>≈</mo></math></span>650 °C, strain hardening and the PLC effect dominate due to dislocation-solute interactions, while grain boundary cracking becomes prominent above <span><math><mo>≈</mo></math></span> 600 °C, coinciding with negligible slip activity within the grains. Specimens tested at ambient temperature show considerable texture evolution and grain distortion, whereas those tested at 650 °C and 870 °C show no evidence of texture evolution or grain distortion but instead grain boundary cracking. At temperatures above <span><math><mrow><mo>≈</mo><mn>900</mn><mo>°</mo><mi>C</mi></mrow></math></span>, the activation energy of the slip systems decreases significantly, allowing plastic deformation to be accommodated through a combination of Orowan dislocation bypassing mechanisms and grain boundary deformation and cracking, which partially restores ductility. Experiments with varying sample thicknesses (1<!--> <!-->mm–2.5<!--> <!-->mm) at ambient, 650 °C, and 870 °C reveal that thinner samples, with smaller grains and larger relative grain boundary areas, show distinct changes in serrated plastic flow, ductility loss, and strength degradation. Enhanced PLC formation in thinner samples compared to thicker ones at the same temperature, combined with reduced ductility, underscores the critical role of grain boundary deformation and cracking in ductility loss at elevated temperatures.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"97 ","pages":"Article 104600"},"PeriodicalIF":10.3,"publicationDate":"2025-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143143420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-05DOI: 10.1016/j.addma.2024.104616
Hao Yu , Quan Zhao , Jiabo Fu , Yanzhen Hu , Jingjing Liang , Jinguo Li , Wei Xu
To design new oxidation resistant Ni superalloys adapted for additive manufacturing, a computational design approach has been constructed in this work. A series of selection criteria and optimization criteria were defined and validated for composition screening, and the genetic algorithm was incorporated into the model to effectively explore the compositional search domain. Accordingly, A new Ni superalloy, AMS-OR, has been developed with the optimal combination of printability, oxidation resistance and mechanical properties. Experimental results show that AMS-OR exhibits excellent printability, achieving crack-free samples across a rather wide range of printing parameters. The strength and ductility of AMS-OR alloy can well outperform the existing Ni commercials as well. After oxidation test, a complete and stable Al2O3 oxide layer forms in the inner layer of the oxide scale with no spallation, demonstrating the favorable oxidation resistance of this alloy which is comparable to the commercial counterparts. The experimentally validated properties in additive manufacturing, mechanical properties and oxidation resistance of novel alloy confirm the effectiveness of the alloy design model in developing high-performance Ni superalloys, which provides a new pathway for developing novel printable alloys with excellent service performance.
{"title":"The design of oxidation resistant Ni superalloys for additive manufacturing","authors":"Hao Yu , Quan Zhao , Jiabo Fu , Yanzhen Hu , Jingjing Liang , Jinguo Li , Wei Xu","doi":"10.1016/j.addma.2024.104616","DOIUrl":"10.1016/j.addma.2024.104616","url":null,"abstract":"<div><div>To design new oxidation resistant Ni superalloys adapted for additive manufacturing, a computational design approach has been constructed in this work. A series of selection criteria and optimization criteria were defined and validated for composition screening, and the genetic algorithm was incorporated into the model to effectively explore the compositional search domain. Accordingly, A new Ni superalloy, AMS-OR, has been developed with the optimal combination of printability, oxidation resistance and mechanical properties. Experimental results show that AMS-OR exhibits excellent printability, achieving crack-free samples across a rather wide range of printing parameters. The strength and ductility of AMS-OR alloy can well outperform the existing Ni commercials as well. After oxidation test, a complete and stable Al<sub>2</sub>O<sub>3</sub> oxide layer forms in the inner layer of the oxide scale with no spallation, demonstrating the favorable oxidation resistance of this alloy which is comparable to the commercial counterparts. The experimentally validated properties in additive manufacturing, mechanical properties and oxidation resistance of novel alloy confirm the effectiveness of the alloy design model in developing high-performance Ni superalloys, which provides a new pathway for developing novel printable alloys with excellent service performance.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"97 ","pages":"Article 104616"},"PeriodicalIF":10.3,"publicationDate":"2025-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143143424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A facile in-situ foaming technology for 3D printing was proposed based on thermoplastic polyurethane (TPU) /thermally expandable microsphere (TEM) systems, which resulted in the formation of both macroscale origami structures with gradient stiffness and uniformly distributed microscale cells in the TPU. The precise fabrication of the printed TPU/TEM foam was investigated by adjusting the printing process parameters, such as printing speed, printing temperature, and extrusion flow rate, with reduced layer-to-layer pore size and porosity owing to in situ expansion and interlayer bonding. With the addition of 4 % TEM, the foam exhibited a microstructure with an average cell size of 76.7 μm, cell density of 5.6 × 106 cells/cm3, and overall printed foam density of 0.32 g/cm3. More interestingly, the 3D printed foamed TPU/TEM system with hierarchical structure exhibited higher densification strain and energy absorption efficiency than the general 3D printed structure. The introduced microscopic cells and their yield deformation after full densification of the macroscopic structure could be the dominant factors for the enhanced energy absorption performance. Based on in situ foaming additive manufacturing, the origami structure with gradient stiffness of TPU/TEM systems can be easily designed by controlling the layers with different TEM contents. Further investigation of the compressive energy-absorption behavior of the origami structures with gradient stiffness showed multi- energy absorption plateaus corresponding to the strength of the printed material in the order of material strength from low to high, thereby achieving controlled yield deformation behavior. Furthermore, the TPU/TEM foam with a hierarchical structure also has the benefit of low thermal conductivity, which was only 0.037 W∙m−1∙K−1 at room temperature. Combined with the advantages of 3D printing personalization, thermoplastic elastomers with thermally expandable microspheres can be proposed as a facile strategy for manufacturing energy-absorbing structures with multi-designability, hierarchical structure, gradient stiffness, and tunable deformation behavior.
{"title":"Facile manufacturing strategy for origami structure of thermoplastic elastomer foam with gradient stiffness by 3D printing","authors":"Shuai Zhang, Shuhuan Yun, Xianzhe Sheng, Jianbin Qin, Guangcheng Zhang, Xuetao Shi","doi":"10.1016/j.addma.2024.104621","DOIUrl":"10.1016/j.addma.2024.104621","url":null,"abstract":"<div><div>A facile in-situ foaming technology for 3D printing was proposed based on thermoplastic polyurethane (TPU) /thermally expandable microsphere (TEM) systems, which resulted in the formation of both macroscale origami structures with gradient stiffness and uniformly distributed microscale cells in the TPU. The precise fabrication of the printed TPU/TEM foam was investigated by adjusting the printing process parameters, such as printing speed, printing temperature, and extrusion flow rate, with reduced layer-to-layer pore size and porosity owing to in situ expansion and interlayer bonding. With the addition of 4 % TEM, the foam exhibited a microstructure with an average cell size of 76.7 μm, cell density of 5.6 × 10<sup>6</sup> cells/cm<sup>3</sup>, and overall printed foam density of 0.32 g/cm<sup>3</sup>. More interestingly, the 3D printed foamed TPU/TEM system with hierarchical structure exhibited higher densification strain and energy absorption efficiency than the general 3D printed structure. The introduced microscopic cells and their yield deformation after full densification of the macroscopic structure could be the dominant factors for the enhanced energy absorption performance. Based on in situ foaming additive manufacturing, the origami structure with gradient stiffness of TPU/TEM systems can be easily designed by controlling the layers with different TEM contents. Further investigation of the compressive energy-absorption behavior of the origami structures with gradient stiffness showed multi- energy absorption plateaus corresponding to the strength of the printed material in the order of material strength from low to high, thereby achieving controlled yield deformation behavior. Furthermore, the TPU/TEM foam with a hierarchical structure also has the benefit of low thermal conductivity, which was only 0.037 W∙m<sup>−1</sup>∙K<sup>−1</sup> at room temperature. Combined with the advantages of 3D printing personalization, thermoplastic elastomers with thermally expandable microspheres can be proposed as a facile strategy for manufacturing energy-absorbing structures with multi-designability, hierarchical structure, gradient stiffness, and tunable deformation behavior.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"97 ","pages":"Article 104621"},"PeriodicalIF":10.3,"publicationDate":"2025-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-05DOI: 10.1016/j.addma.2024.104607
Yanlong Wu , Xu Chen , Guangbin Zhao , Jinyong Qiu , Kankan Deng , Jian Qiao , Yaxiong Liu
Vat photopolymerization (VPP) is widely studied for manufacturing ceramic parts due to its cost-effectiveness, high efficiency, and excellent resolution. However, defects in complex, thick-walled structures induced by manufacturing process often restrict its application. This study reports the successful development of defect-free, thick-walled ceramic parts using VPP by incorporating gamma-valerolactone (GVL), a circular, safe, biomass-derived diluent, into SiO2 suspension. This addition effectively controlled defect formation throughout both printing and debinding. Specifically, introducing 50 vol% GVL into organic solution reduced the viscosity of the SiO2 suspension by 38–48 % at a high solid loading of 67 vol%, thereby eliminating inner pore defects during printing. Furthermore, this modification reduced the volume shrinkage of the SiO2 suspension during printing by 40 %, significantly alleviating residual shrinkage stress. Remarkably, the toughness of the green sample containing 50 vol% GVL remained exceptionally high during printing and debinding, effectively resisting stress-induced defect formation, particularly interlayer cracks. Microstructural analysis revealed that sufficient exhaust ducts formed when the diluent evaporated at the first debinding stage under lower temperatures, facilitating the release of pyrolyzed gases at the second debinding stage under higher temperatures and thus mitigating gas expansion stress. The defect-free mechanisms can mainly be the balance of the mechanical properties and the process-induced stresses. These findings indicate that ceramic suspensions enhanced with high concentration of non-reactive diluent hold significant promise for manufacturing defect-free, thick-walled ceramic parts through VPP in industrial applications.
{"title":"Development of thick-walled ceramic parts via vat photopolymerization using low-viscosity non-reactive diluent as an additive","authors":"Yanlong Wu , Xu Chen , Guangbin Zhao , Jinyong Qiu , Kankan Deng , Jian Qiao , Yaxiong Liu","doi":"10.1016/j.addma.2024.104607","DOIUrl":"10.1016/j.addma.2024.104607","url":null,"abstract":"<div><div>Vat photopolymerization (VPP) is widely studied for manufacturing ceramic parts due to its cost-effectiveness, high efficiency, and excellent resolution. However, defects in complex, thick-walled structures induced by manufacturing process often restrict its application. This study reports the successful development of defect-free, thick-walled ceramic parts using VPP by incorporating gamma-valerolactone (GVL), a circular, safe, biomass-derived diluent, into SiO<sub>2</sub> suspension. This addition effectively controlled defect formation throughout both printing and debinding. Specifically, introducing 50 vol% GVL into organic solution reduced the viscosity of the SiO<sub>2</sub> suspension by 38–48 % at a high solid loading of 67 vol%, thereby eliminating inner pore defects during printing. Furthermore, this modification reduced the volume shrinkage of the SiO<sub>2</sub> suspension during printing by 40 %, significantly alleviating residual shrinkage stress. Remarkably, the toughness of the green sample containing 50 vol% GVL remained exceptionally high during printing and debinding, effectively resisting stress-induced defect formation, particularly interlayer cracks. Microstructural analysis revealed that sufficient exhaust ducts formed when the diluent evaporated at the first debinding stage under lower temperatures, facilitating the release of pyrolyzed gases at the second debinding stage under higher temperatures and thus mitigating gas expansion stress. The defect-free mechanisms can mainly be the balance of the mechanical properties and the process-induced stresses. These findings indicate that ceramic suspensions enhanced with high concentration of non-reactive diluent hold significant promise for manufacturing defect-free, thick-walled ceramic parts through VPP in industrial applications.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"97 ","pages":"Article 104607"},"PeriodicalIF":10.3,"publicationDate":"2025-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143143351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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