Additive manufacturing最新文献

{"title":"Optimizing AlN hydrolysis process to fabricate coated modified powders for improving the properties of Si3N4/SiAlON ceramics prepared by Vat Photopolymerization","authors":"Wei-Kang Li ,&nbsp;Ren-Zhong Zhang ,&nbsp;Jia-Min Wu ,&nbsp;Lin Guo ,&nbsp;Wei-Hao Cai ,&nbsp;Xin Lin ,&nbsp;Hai-Sheng Xu ,&nbsp;Fen Wang ,&nbsp;Yu-Sheng Shi","doi":"10.1016/j.addma.2024.104460","DOIUrl":"10.1016/j.addma.2024.104460","url":null,"abstract":"<div><div>The preparation of complex structural parts of Si₃N₄ and its composite ceramics using conventional methods is difficult. The Vat Photopolymerization (VPP) technique is regarded as an effective method for the preparation of ceramic materials. However, due to the high absorption of ultraviolet (UV) light and high refractive index of Si₃N₄, it is challenging to realize its complex structure via VPP technique. AlN and Si₃N₄ can be compounded to form SiAlON phase, and AlN powders can be hydrolyzed to produce Al(OH)₃ that can be easily dehydrated. In this study, Si₃N₄@Al₂O₃ and AlN@Al₂O₃ powders were prepared by mixing Si₃N₄ and AlN powders by hydrolysis. Subsequently, Si₃N₄/SiAlON composite ceramics were prepared by VPP. With the addition of 10 vol% AlN, the viscosity of ceramic slurry was found to be 0.50 Pa·s. Furthermore, the curing depth was observed to reach 49.46 ± 2.15 μm at 800 mJ/cm². The sintered ceramics exhibited the formation of the excellent β-Si₃N₄/β-SiAlON phase. The relative density, bending strength, hardness, fracture toughness and thermal conductivity was determined to be 92.61 ± 2.51 %, 402.91 ± 9.61 MPa, 21.11 ± 0.61 GPa, 6.33 ± 0.25 MPa·<span><math><msup><mrow><mi>m</mi></mrow><mrow><mstyle><mrow><mfrac><mrow><mn>1</mn></mrow><mrow><mn>2</mn></mrow></mfrac></mrow></mstyle></mrow></msup></math></span> and 33.17 ± 1.01 W·m⁻¹·K⁻¹, respectively. This study introduces a novel approach to cladding modification of Si₃N₄ and AlN, as well as the preparation of Si₃N₄/SiAlON composite ceramics with exceptional properties via VPP.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"94 ","pages":"Article 104460"},"PeriodicalIF":10.3,"publicationDate":"2024-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358086","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}

{"title":"Early age shrinkage mitigation and quantitative study on water loss kinetics of 3D printed foam concrete modified with superabsorbent polymers","authors":"Chao Liu ,&nbsp;Nemkumar Banthia ,&nbsp;Yifan Shi ,&nbsp;Zijian Jia ,&nbsp;Yamei Zhang ,&nbsp;Yu Chen ,&nbsp;Yuanliang Xiong ,&nbsp;Chun Chen","doi":"10.1016/j.addma.2024.104448","DOIUrl":"10.1016/j.addma.2024.104448","url":null,"abstract":"<div><div>Due to direct exposure to the environment during the printing process and after printing and its own porous characteristics, 3D printed foam concrete (3DPFC) will inevitably have a large shrinkage at early age. In this study, the early age shrinkage of 3DPFC was modified by using various dosages of superabsorbent polymer (SAP). The water loss kinetics of 3DPFC at early age were elucidated, and the mechanism influencing early age shrinkage of 3DPFC was revealed. The 8-hour total shrinkage of 3DPFC with two foam contents was reduced by 23.1% and 24.3% at most, respectively. Based on low-field nuclear magnetic transverse relaxation time, liquids in bubble liquid film, capillary pores of the matrix, and inside SAP were quantified and tracked in real time. Under exposure conditions, there exists a quantitative relationship between internal water loss variations in 3DPFC and the matrix <em>T</em>₂₁ peak water (water adsorbed by binder particles and small capillary water between particles), bubble volume fraction, and surface tension of the matrix pore solution. The early age shrinkage of 3DPFC is indeed influenced by the combined effect of water loss and bubble volume fraction.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"94 ","pages":"Article 104448"},"PeriodicalIF":10.3,"publicationDate":"2024-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322698","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}

{"title":"Looping: Load-oriented optimized paths in non-planar geometry","authors":"Johann Kipping,&nbsp;Doran Nettig,&nbsp;Thorsten Schüppstuhl","doi":"10.1016/j.addma.2024.104426","DOIUrl":"10.1016/j.addma.2024.104426","url":null,"abstract":"<div><div>Effective material utilization in the additive manufacturing of lightweight components is of increasing importance. The Looping (Load-oriented optimized paths in non-planar geometry) method presented in this work enables the translation of desired material orientations into suitable manufacturing instructions. The desired material orientations are derived from the principal stress directions that would manifest for an isotropic material. By employing non-planar slicing, these orientations can be followed by the deposited material beads. The novel path planning algorithm combines load-orientation and path continuity. While this can be beneficial for load-oriented printing in general, it is an especially significant step for load-oriented printing of continuous fiber reinforced polymers. The ability to follow desired material orientations with continuous paths shows particularly high potential for highly anisotropic fiber reinforced polymers. The algorithms are implemented and demonstrated in a complete process chain. However, challenges remain in the optimization of the orientation and manufacturing system for fiber reinforced polymers, which are not the focus of this work. For this reason, the process chain is realized for a neat polymer. In this context, the developed method is computationally evaluated with respect to layer height, unfilled areas, manufacturing time, geometric accuracy, and physical fabrication. The continuous and load-oriented path planning algorithm is tested against a continuous contour parallel approach and planar slicing through tensile testing. The investigations show an applicability of the process chain to successfully produce complex parts with the desired load-oriented paths. The proposed algorithm shows an increase in mechanical performance compared to the contour parallel approach highlighting its potential for non-planar printing. However, it is also found that limitations of the non-planar manufacturing process still limit its potential to surpass optimally oriented planar printing for the investigated geometry.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"94 ","pages":"Article 104426"},"PeriodicalIF":10.3,"publicationDate":"2024-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vat photopolymerization based digital light processing 3D printing hydrogels in biomedical fields: Key parameters and perspective","authors":"Zhe Lu ,&nbsp;Weizi Gao ,&nbsp;Fukang Liu,&nbsp;Jingjing Cui,&nbsp;Shiwei Feng,&nbsp;Chen Liang,&nbsp;Yunlong Guo,&nbsp;Zhenxiang Wang,&nbsp;Zhijie Mao,&nbsp;Biao Zhang","doi":"10.1016/j.addma.2024.104443","DOIUrl":"10.1016/j.addma.2024.104443","url":null,"abstract":"<div><div>Vat photopolymerization (VP) based digital light processing (DLP) 3D printing technology gains prominence in biomedical fields, particularly for creating complex tissue structures and aiding in regeneration. Hydrogels, known for their high-water content and biocompatibility, serve as an ideal material used in VP based DLP 3D printing for mimicking biological tissues. The review examines the crucial components of VP based DLP 3D printing of hydrogels in three categories: materials, including monomers and crosslinkers that make up of hydrogels; equipment, featuring various types of VP based DLP 3D printers; and printing parameters, such as light source and exposure time. The application of VP based DLP 3D printed hydrogels at different levels of biomedical field is discussed, providing an overview of the current trends and future possibilities of VP based DLP 3D printing hydrogels in biomedical science.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"94 ","pages":"Article 104443"},"PeriodicalIF":10.3,"publicationDate":"2024-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142328285","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}

{"title":"Achieving high strength-ductility of AZ91 magnesium alloy via wire-arc directed energy deposition assisted by interlayer friction stir processing","authors":"Jingxun Wei ,&nbsp;Changshu He ,&nbsp;Mofan Qie ,&nbsp;Yunan Liu ,&nbsp;Hao Zhou ,&nbsp;Chenxi Kang ,&nbsp;Gaowu Qin","doi":"10.1016/j.addma.2024.104453","DOIUrl":"10.1016/j.addma.2024.104453","url":null,"abstract":"<div><div>The coarse grain size and poor mechanical properties of wire-arc directed energy deposition (DED) magnesium (Mg) alloys have hindered their wider application. In this study, the AZ91 Mg alloy component was fabricated by wire-arc DED assisted by interlayer friction stir processing (IFSP), and the highest strength and elongation were obtained in wire-arc DED AZ91 Mg alloy, which was mainly attributed to grain refinement, fragmentation/dispersion/dissolution of β-Mg₁₇Al₁₂ phase and heterogeneous microstructure in the IFSP stir zone (SZ). The formation of heterogeneous structure is caused by the fact that the refined grains in the SZ of the previous layer are affected by the thermal cycling of the subsequent additive manufacturing process, which led to different degrees of grain growth in different micro-zones within a SZ, and ultimately formed the microstructure characteristics with alternating distribution of coarse and fine grains. Compared with the wire-arc DED samples, the ultimate tensile strength of the wire-arc DED + IFSP samples in the perpendicular and parallel to the building directions increased from 284 and 264 MPa to 315 and 324 MPa, respectively. These values are comparable to those of their wrought counterparts, and the elongation increased by over 50 %. This study thus provides new insights into microstructure modification and performance enhancement of wire-arc DED fabricated Mg-alloys via a novel IFSP technique.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"94 ","pages":"Article 104453"},"PeriodicalIF":10.3,"publicationDate":"2024-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142318868","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}

{"title":"Laser directed energy deposited eutectic high entropy alloy with tailored lamella structure via interlayer pause strategy","authors":"Zhouyang He ,&nbsp;Xingbao Qiu ,&nbsp;Xilei Bian ,&nbsp;Shiwei Wu ,&nbsp;Xiaolong Yu ,&nbsp;Chenwei Liu ,&nbsp;Zhen Hu ,&nbsp;Yuefei Jia ,&nbsp;Weisen Zheng ,&nbsp;Jinqiang Shi ,&nbsp;Zhibin Wu ,&nbsp;Xiaogang Lu ,&nbsp;Yandong Jia ,&nbsp;Gang Wang","doi":"10.1016/j.addma.2024.104471","DOIUrl":"10.1016/j.addma.2024.104471","url":null,"abstract":"<div><div>Eutectic high entropy alloys (EHEAs) have garnered significant attention due to their unique heterogeneous lamella structure, which imparts a desirable strength-ductility combination. Additive manufacturing (AM) techniques further exploit the advantageous properties of EHEAs through efficient fabrication and rapid heating/cooling processes. In this study, we fabricate near-fully dense and crack-free AlCoCrFeNi_2.1 EHEA samples with an alternating nano-scale eutectic lamellar structure composed of disordered face-centered cubic (FCC) and ordered B2 phases using the laser directed energy deposition (LDED) method. By using a novel and simple interlayer pause strategy, we have found that the eutectic lamellar structure can be significantly refined, achieving approximately 40% greater refinement compared to the case without interlayer pause. The optimized EHEA exhibits an exceptionally high strength of 1214 MPa and a sufficient uniform elongation of 16.3%, outperforming the non-interlayer-pause counterpart by 14% in strength and 47% in uniform elongation. The superior mechanical properties of the AlCoCrFeNi_2.1 EHEA are attributed to the synergistic effects of heterogeneous deformation-induced (HDI) strengthening and strain hardening mechanisms. Furthermore, the refined eutectic lamellar structure can effectively mitigate stress concentration mediated the formation of microcracks, thereby delaying fracture and maintaining plasticity. The interlayer pause strategy presented in this work offers a simple yet effective approach and valuable insights for the preparation of metallic materials with exceptional mechanical properties via LDED process.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"94 ","pages":"Article 104471"},"PeriodicalIF":10.3,"publicationDate":"2024-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142423470","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}

{"title":"Additive manufacturing of high-strength low-alloy AISI 4340 steel with an optimal strength-ductility-toughness trade-off","authors":"Ju Yao,&nbsp;Qiyang Tan,&nbsp;Jeffrey Venezuela,&nbsp;Andrej Atrens,&nbsp;Ming-Xing Zhang","doi":"10.1016/j.addma.2024.104496","DOIUrl":"10.1016/j.addma.2024.104496","url":null,"abstract":"<div><div>Additive manufacturing (AM) has revolutionised steel part fabrication, yet not all steels are amenable to its unique solidification features, characterised by cyclic and rapid heating/cooling, and directional solidification. These conditions often result in challenges such as columnar grain formation, microstructural heterogeneity, and consequently, inferior mechanical performance, brittleness and severe anisotropy in particular. Recent studies have adopted inoculation or post-fabrication treatments to address this issue, but often entailing extra cost and processing time. This study aims to verify that some steels such as AISI 4340 steel are inherently compatible to AM, producing components that are innately robust and ready for use in the as-built state. The medium carbon content and low alloying element concentration enable AM processing to produce a uniform and refined bainite microstructure with minimal elemental segregation, avoiding the formation of unstable retained austenite. The high AM-processability of this steel is demonstrated by achieving high densification (&gt;99.9 %) across a broad processing window, which allows precise microstructural control via proper tunning the processing parameter modifications, inducing a transition from upper bainite to lower bainite dominance, to tailor mechanical properties for specific applications. The as AM-fabricated AISI 4340 steel exhibits a good combination of strength, ductility, and toughness, manifested by a yield strength range from 1240 to 1370 MPa, an ultimate tensile strength from 1360 to 1740 MPa, an elongation from 7 % to 14 %, and an impact toughness range of 11–44 J. The mechanical properties of the AM-fabricated 4340 steel are comparable to those of the wrought counterpart and superior to the majority of other AM-fabricated steels. This research reveals the high potential of AM to process high-strength low-alloy steels.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"94 ","pages":"Article 104496"},"PeriodicalIF":10.3,"publicationDate":"2024-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142533866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Operando visualization of porous metal additive manufacturing with foaming agents through high-speed x-ray imaging","authors":"Chenxi Tian ,&nbsp;Jenniffer Bustillos ,&nbsp;Akane Wakai ,&nbsp;Ashlee Gabourel ,&nbsp;Samuel J. Clark ,&nbsp;Kamel Fezzaa ,&nbsp;Atieh Moridi","doi":"10.1016/j.addma.2024.104505","DOIUrl":"10.1016/j.addma.2024.104505","url":null,"abstract":"<div><div>Porous metals find extensive applications in soundproofing, filtration, catalysis, and energy-absorbing structures, thanks to their unique internal pore structure and high specific strength. In recent years, there has been an increasing interest in fabricating porous metals using additive manufacturing (AM), leveraging its unique advantages, including improved design freedom, spatial material control, and cost-effective small-batch production. In this study, we conducted pioneering operando visualization of AM porous metal using a laser powder bed fusion (L-PBF) setup combined with a high-speed synchrotron x-ray imaging system. Single track printing experiments using Ti6Al4V (Ti64) combined with titanium hydride (TiH₂) and sodium carbonate (Na₂CO₃) as foaming agents, with varying mixing ratios were performed under different processing conditions. The results elucidate the dynamic development of porosity formation. The average pore size is significantly influenced by the particle size of foaming agents when pore coalescence is absent. For all foaming agent content tested in the current study, the number of pores is found to be more sensitive to changes in laser power than in laser scanning speed. Increasing linear energy density (increasing laser power or reducing laser scanning speed) promotes the foaming agent activation thereby porosity formation. However, high linear energy density skews pore distribution towards the surface despite forming deeper melt pools. In addition, the impact of additional factors including foaming agent’s laser absorptivity and decomposition kinetics with respect to AM time scales should be carefully considered to avoid ineffective activation of foaming agents during the AM of porous metals.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"94 ","pages":"Article 104505"},"PeriodicalIF":10.3,"publicationDate":"2024-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142533991","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}

{"title":"Corrigendum to “A trivariate T-spline based direct-slicing framework for support-free additive manufacturing” [Addit. Manuf. 65 (2023) 103446]","authors":"Bin Li ,&nbsp;Hongyao Shen ,&nbsp;Jianzhong Fu","doi":"10.1016/j.addma.2024.104493","DOIUrl":"10.1016/j.addma.2024.104493","url":null,"abstract":"","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"94 ","pages":"Article 104493"},"PeriodicalIF":10.3,"publicationDate":"2024-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142659470","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}

{"title":"In-situ twin-wire additive manufacturing: Integrated fabrication of refractory medium entropy alloy, correlation between orientation and slip systems activation","authors":"Zhe Li ,&nbsp;Liang Wang ,&nbsp;Chen Liu ,&nbsp;Baoxian Su ,&nbsp;Binbin Wang ,&nbsp;Binqiang Li ,&nbsp;Weikun Zhang ,&nbsp;Qingda Zhang ,&nbsp;Zhiwen Li ,&nbsp;Liangshun Luo ,&nbsp;Ruirun Chen ,&nbsp;Jürgen Eckert ,&nbsp;Yanqing Su","doi":"10.1016/j.addma.2024.104454","DOIUrl":"10.1016/j.addma.2024.104454","url":null,"abstract":"<div><div>An innovative approach, i.e., twin-wire ‘co-pointed’ synergistic additive manufacturing implemented to create crack-free refractory medium entropy alloys eliminating costly powders, has been realized in this work. A self-designed twin-wire co-pointed strategy is suitable for near and high melting point elements. While the electron beam freeform fabrication (EBF³) process exhibits low porosity and defects and significant compositional homogeneity under a stabilized liquid bridge transfer mode, the mechanical properties and their dependence on orientation were studied in detail. Microstructural results of fabricated target non-equiatomic TiZrNbHf reveals a single-phase body centered cubic structure and typical columnar features with a &lt;100&gt;//building direction (BD) fiber texture. Tensile specimens taken from horizontal (&lt;100&gt;⊥tensile direction) and vertical (&lt;100&gt;//tensile direction) directions exhibit a comparable yield strength of 615.39 ± 7.88 MPa and 592.84 ± 5.95 MPa, with the failure elongations of 20.56 ± 1.00 % and 21.45 ± 0.72 %, respectively. In-situ EBSD characterization during tension reveals dislocation slip with {112} as the dominant plane as the only deformation mode. However the grain orientation affects the activation of slip systems, revealing non-Schmid factor behavior exists and determined by the grain boundary misorientation angle rather than the geometric compatibility factor. Horizontal grains enhanced the strength through a hard-oriented heterogeneous structure, while the vertical ones are prone to slip transfer on the same plane and wavy cross-slip to promote uniform deformation.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":"94 ","pages":"Article 104454"},"PeriodicalIF":10.3,"publicationDate":"2024-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322680","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}