Additive manufacturing letters最新文献

Modelling process monitoring data in laser powder bed fusion: A pragmatic route to additive manufacturing quality assurance 激光粉末床熔融过程监控数据建模：快速成型制造质量保证的实用途径

IF 4.2

Additive manufacturing letters Pub Date : 2024-10-29 DOI: 10.1016/j.addlet.2024.100252

{"title":"Modelling process monitoring data in laser powder bed fusion: A pragmatic route to additive manufacturing quality assurance","authors":"","doi":"10.1016/j.addlet.2024.100252","DOIUrl":"10.1016/j.addlet.2024.100252","url":null,"abstract":"<div><div>Quality assurance remains a significant challenge for laser powder bed fusion and metal additive manufacturing. Despite system manufacturers offering process monitoring as a possible solution, datasets are large and cumbersome with practical use limited without direct comparative data. Model datasets would enable individual build validation, highlight deviations, and facilitate intelligent build planning whereby challenging features or build strategies could be pre-emptively assessed.</div><div>Herein a pragmatic approach has been developed to model process monitoring data from a commercial system using a relatively simple algorithm. Using a heuristic method, the algorithm response has been fitted to an experimental dataset to derive governing constants and their relationship to key process parameters. Predictability of constants and model fit has been shown to improve with increasing line energy up to a maximum R<sup>2</sup>=0.8. Algorithm variable trends, supported by corresponding sensitivity analysis, identified two different behavioural regimes. Under low linear energy density (<0.2J/mm) the cumulative spacetime proximity time-weight variable shows a low sensitivity index, characterised by a flat model response reflected in the experimental data. At higher energies (≥0.2J/mm) algorithm variables become more predictable, reflected in stabilising sensitivity indices, as measurements adopt a form characteristic of the cumulative spacetime proximity function.</div><div>Effectiveness has been demonstrated through presentation of experimental and model data. Refining the methodology to accommodate noise, geometry, and systematic behaviours are identified as key steps to future development. This feasibility study has laid the groundwork for a generalised predictive tool, capable of realising the quality assurance ambitions promised by laser powder-bed fusion process monitoring.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572438","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

Drop-on-demand 3D printing of programable magnetic composites for soft robotics 用于软机器人的可编程磁性复合材料的按需滴落三维打印技术

IF 4.2

Additive manufacturing letters Pub Date : 2024-10-28 DOI: 10.1016/j.addlet.2024.100250

{"title":"Drop-on-demand 3D printing of programable magnetic composites for soft robotics","authors":"","doi":"10.1016/j.addlet.2024.100250","DOIUrl":"10.1016/j.addlet.2024.100250","url":null,"abstract":"<div><div>Soft robotics have become increasingly popular as a versatile alternative to traditional robotics. Magnetic composite materials, which respond to external magnetic fields, have attracted significant interest in this field due to their programmable two-way actuation and shape-morphing capabilities. Additive manufacturing (AM)/3D printing allows for the incorporation of different functional composite materials to create active components for soft robotics. However, current AM methods have limitations, especially when it comes to printing smart composite materials with high functional material content. This is a key requirement for enhancing responsiveness to external stimuli. Commonly used AM methods for smart magnetic composites, such as direct ink writing (DIW), confront challenges in achieving discontinuous printing, and enabling multi-material control at the voxel level, while some AM techniques are not suitable for producing composite materials. To address these limitations, we employed high-viscosity drop-on-demand (DoD) jetting and developed programmable magnetic composites filled with micron-sized hard magnetic particles. This method bridges the gap between conventional ink-jetting and DIW, which require printing inks with viscosities at opposite ends of the spectrum. This high-viscosity DoD jetting enables continuous, discontinuous, and non-contact printing, making it a versatile and effective method for 3D printing functional magnetic composites even with micron-sized fillers. Furthermore, we demonstrated stable magnetic domain programming and two-way shape-morphing actuations of printed structures for soft robotics. In summary, our work highlights high-viscosity DoD jetting as a promising method for printing functional magnetic composites and other similar materials for a wide range of applications.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142560560","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

A non-melting additive approach to structural repair of aluminum aircraft fastener holes 铝制飞机紧固件孔结构修复的非熔化添加剂方法

IF 4.2

Additive manufacturing letters Pub Date : 2024-10-23 DOI: 10.1016/j.addlet.2024.100249

{"title":"A non-melting additive approach to structural repair of aluminum aircraft fastener holes","authors":"","doi":"10.1016/j.addlet.2024.100249","DOIUrl":"10.1016/j.addlet.2024.100249","url":null,"abstract":"<div><div>The damage to fastener holes in aerospace aluminum structures presents significant challenges for aircraft durability, and conventional bushing methods for repairing oversized holes often fall short due to the lack of metallurgical bonding and limited edge distance availability. This study investigates additive friction stir deposition, a non-melting additive process, as a viable alternative for the structural repair of aerospace fastener holes. The repair process, demonstrated on AA7050 (Al-Zn-Mg-Cu-Zr) hole structures, involves filling oversized holes with new material and machining to restore the original hole size. The repaired hole coupons are defect-free and exhibit good fatigue performance under fully reversed tension-compression loading (<em>R</em> = -1). At a nominal stress amplitude of 123.5 MPa, the average number of cycles to failure is 12,666 for unrepaired baseline coupons and 17,372 for effectively repaired coupons. Restoring complex geometries without compromising fatigue performance has been difficult in aerospace applications; this study marks the first demonstration of additive repair that consistently outperforms the unrepaired baseline coupons. Notably, the result is achieved through a low-energy, cost-effective solution without the need for post-repair heat treatment. Except for a few outliers, the post-repair fatigue performance generally remains inferior to that of undamaged, pristine coupons, likely due to precipitate evolution in AA7050 caused by the thermomechanical processing nature of additive friction stir deposition. This evolution weakens the repair region and the adjacent base material, leading to faster crack initiation and growth compared to the properly aged base material, AA7050-T7451.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554068","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

Enabling tailored microstructures by hybrid directed energy deposition processing of a nickel-based superalloy 通过混合定向能沉积加工镍基超合金实现定制微结构

IF 4.2

Additive manufacturing letters Pub Date : 2024-10-16 DOI: 10.1016/j.addlet.2024.100248

{"title":"Enabling tailored microstructures by hybrid directed energy deposition processing of a nickel-based superalloy","authors":"","doi":"10.1016/j.addlet.2024.100248","DOIUrl":"10.1016/j.addlet.2024.100248","url":null,"abstract":"<div><div>The technological advances in additive manufacturing, particularly laser based directed energy deposition (DED), revolutionized the production of complex metal components. Despite this progress, the oriented heat flux and several reheating thermal cycles can induce a strongly textured microstructure, which induces an anisotropic mechanical behavior. In addition, considerable residual stresses typically require additional post-processing. Therefore, hybrid process chains for additive manufacturing (AM) are being developed, which aim at integrating conventional post-processing into the AM process. However, a detailed investigation of thermal and mechanical effects of such hybrid processes on the mechanical properties and their interrelation is lacking. In an experimental study, we explore the integration of thermal and mechanical processing steps within the DED process chain to locally tailor microstructures and mechanical properties. Through electron backscatter diffraction measurements, we demonstrate significant microstructural changes of DED-manufactured nickel-based superalloy samples using deep rolling and laser heat treatment. A mechanical surface deformation induces microstructural misorientation leading to an increase in hardness down to substantial depth of several hundred micrometers. Additionally, the targeted management of heat input during laser heat treatment results in different grain morphologies and sizes, affecting average microhardness within a significant depth. The results demonstrate the potential for microstructural tailoring using hybrid AM process chains, while a substantial sensitivity of the microstructure to thermal and mechanical load emphasizes the importance of a precise process control. This work provides an understanding of the process-microstructure-property relationship required for developing new process pathways in hybrid AM that integrate thermal and mechanical processes into DED manufacturing.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142445366","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

An integrated hybrid wire-arc directed energy deposition, friction stir processing, and milling system for multi-track, multi-layer part manufacturing 用于多轨道、多层零件制造的线弧定向能沉积、摩擦搅拌加工和铣削综合混合系统

IF 4.2

Additive manufacturing letters Pub Date : 2024-10-11 DOI: 10.1016/j.addlet.2024.100247

{"title":"An integrated hybrid wire-arc directed energy deposition, friction stir processing, and milling system for multi-track, multi-layer part manufacturing","authors":"","doi":"10.1016/j.addlet.2024.100247","DOIUrl":"10.1016/j.addlet.2024.100247","url":null,"abstract":"<div><div>Wire-based Directed Energy Deposition (DED) is a widely-used manufacturing method due to its high productivity and large part fabrication capability. Meanwhile, Friction Stir Processing (FSP) is a solid-state joining process that can modify microstructure and weld lightweight alloys. Additionally, wire-based DED printed parts need machining process to achieve the desired dimensional accuracy. To take advantage of all these three processes, this work proposes an integrated hybrid system by combining the wire-arc DED, FSP, and milling processes into a standalone system which can fabricate superior materials in a multi-track, multi-layer manner for the first time. The integrated system can improve dimensional accuracy and productivity by processing the workpiece without the need to move it between different systems. It is demonstrated that a 150 × 40 × 21 mm<sup>3</sup> block of aluminum alloy AA5183 can be fabricated using the hybrid wire-DED/FSP/milling process from wire feedstock. Material characterization shows that the hybrid process is able to refine the grain size by two orders of magnitude to sub-micron scale, while eliminating all the pores and microcracks produced by the DED process. These enhancements result in significantly improved mechanical properties including Young's modulus (15 %), yield strength (161 %), ultimate strength (33 %), and hardness (55 %) without compromising ductility.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433430","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 laser power during laser powder bed fusion on microstructure of joining interface between Tungsten and AISI 316L steel 激光粉末床熔融过程中的激光功率对钨和 AISI 316L 钢连接界面微观结构的影响

IF 4.2

Additive manufacturing letters Pub Date : 2024-10-09 DOI: 10.1016/j.addlet.2024.100246

引用次数: 0

Preparation of continuous carbon fiber reinforced PA6 prepreg filaments with high fiber volume fraction 制备高纤维体积分数的连续碳纤维增强 PA6 预浸丝

IF 4.2

Additive manufacturing letters Pub Date : 2024-10-02 DOI: 10.1016/j.addlet.2024.100245

{"title":"Preparation of continuous carbon fiber reinforced PA6 prepreg filaments with high fiber volume fraction","authors":"","doi":"10.1016/j.addlet.2024.100245","DOIUrl":"10.1016/j.addlet.2024.100245","url":null,"abstract":"<div><div>High-performance continuous carbon fiber prepreg filaments have been a research hotspot in the field of additive manufacturing in recent years, and are considered to be an effective option for improving the mechanical strength of thermoplastic composite parts. However, the effect of fiber volume fraction on the microstructure and tensile properties of 3D printed prepreg filaments remains miss. Therefore, this study selected suitable impregnation processes and materials to prepare prepreg filaments with different fiber volume fraction and investigated their mechanical properties and microscopic morphologies. The results show that the increase of fiber volume fraction effectively promoted the interface bonding between fiber and resin, and increased capacity for load transfer. When the fiber volume fraction was 54.0 %, the tensile strength of the prepreg filaments and specimens reached 1977 MPa and 334 MPa, respectively. This study can provide a process optimization strategy for the preparation of more types of continuous fiber prepreg filaments with high fiber volume fraction, as well as a data reference for the preparation of high-performance 3D-printed thermoplastic composites.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142422867","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

Deep learning for melt pool depth contour prediction from surface thermal images via vision transformers 通过视觉转换器进行深度学习，从表面热图像预测熔池深度轮廓

IF 4.2

Additive manufacturing letters Pub Date : 2024-09-29 DOI: 10.1016/j.addlet.2024.100243

{"title":"Deep learning for melt pool depth contour prediction from surface thermal images via vision transformers","authors":"","doi":"10.1016/j.addlet.2024.100243","DOIUrl":"10.1016/j.addlet.2024.100243","url":null,"abstract":"<div><div>Anomalous melt pools during metal additive manufacturing (AM) can lead to deteriorated mechanical and fatigue performance. In-situ monitoring of the melt pool subsurface morphology requires specialized equipment that may not be readily accessible or scalable. Therefore, we introduce a machine learning framework to correlate in-situ two-color thermal images observed via high-speed color imaging to the two-dimensional profile of the melt pool cross-section. We employ a hybrid CNN-Transformer architecture to establish a correlation between single bead off-axis thermal image sequences and melt pool cross-section contours measured via optical microscopy. Specifically, a ResNet model embeds the spatial information contained within the thermal images to a latent vector, while a Transformer model correlates the sequence of embedded vectors to extract temporal information. The performance of this model is evaluated through dimensional and geometric comparisons to the corresponding experimental no-powder melt pool observations. Our framework is able to model the curvature of the subsurface melt pool structure, with improved performance in high energy density regimes compared to analytical models. Additionally, the use of ratiometric temperature estimates improves the accuracy of the model predictions compared to monochromatic imaging. This work establishes a framework extensible towards powder-based AM builds.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142422438","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 laser parameters and shielding gas flow on co-axial photodiode-based melt pool monitoring signals in laser powder bed fusion 激光参数和屏蔽气体流量对激光粉末床熔融中基于同轴光电二极管的熔池监测信号的影响

IF 4.2

Additive manufacturing letters Pub Date : 2024-09-19 DOI: 10.1016/j.addlet.2024.100244

{"title":"Effect of laser parameters and shielding gas flow on co-axial photodiode-based melt pool monitoring signals in laser powder bed fusion","authors":"","doi":"10.1016/j.addlet.2024.100244","DOIUrl":"10.1016/j.addlet.2024.100244","url":null,"abstract":"<div><div>Melt pool monitoring using co-axial photodiodes is increasingly used for online quality monitoring in PBF-LB AM. However, the fundamental correlations between different processing conditions and the co-axial photodiode signals are not well understood. In this study the impact of laser parameters and the shielding gas flow speed on co-axial photodiode-based melt pool monitoring signals is established. It is shown that laser power has positive linear correlation with the photodiode signal, while the correlation with scanning speed is non-linear in the form of <em>y</em>=ax<sup>–b</sup>. The focal point position, scanning orientation and shielding gas flow speed have highly non-linear response on the photodiode signal, depending on the combinatorial effects of the parameters. These underlying physical correlations should be carefully assessed and taken into consideration when trying to establish correlations between photodiode-based melt pool monitoring signal and defect formation in the PBF-LB process.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772369024000525/pdfft?md5=cbf9c1ba3b0f65a2fea5968c1f650aaa&pid=1-s2.0-S2772369024000525-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142316051","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

Additively manufactured Nb-Ti-Si based alloy: As-built and heat-treated conditions 以铌钛硅为基础的添加式制造合金：坯料和热处理条件

IF 4.2

Additive manufacturing letters Pub Date : 2024-09-17 DOI: 10.1016/j.addlet.2024.100242

{"title":"Additively manufactured Nb-Ti-Si based alloy: As-built and heat-treated conditions","authors":"","doi":"10.1016/j.addlet.2024.100242","DOIUrl":"10.1016/j.addlet.2024.100242","url":null,"abstract":"<div><p>This work aims to fully characterise the Nb-Ti-Si based alloy (Nb-26Ti-16Si-2.2Al-2Cr), processed by the electron-beam powder-bed-fusion in both as-built and heat-treated conditions, to elucidate the microstructure-property relationships. The as-built condition has [001]-oriented columnar grains of the Nb<sub>3</sub>Si phase with the Nbss phase dispersed throughout the microstructure. The microhardness is 645.2 ± 6.7 HV<sub>0.5</sub>, and the indentation fracture toughness shows distinct directionality: 7.7 MPa·m<sup>1/2</sup> in the horizontal direction compared to 5.3 MPa·m<sup>1/2</sup> in the vertical direction. Both properties are comparable to the cast version. The directionality is attributed to the underlying mechanisms such as crack bridging, arrest, and micro-crack formation. By contrast, in the heat-treated condition, the alloy exhibits a dual-phase microstructure (Nbss and Nb<sub>5</sub>Si<sub>3</sub> phases) with near-equiaxed grain shape due to the Nb<sub>3</sub>Si phase decomposition. The fracture toughness increases to 12.1 MPa·m<sup>1/2</sup>, at the expense of a reduced microhardness of 564.4 ± 15.0 HV<sub>0.5</sub>.</p></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772369024000501/pdfft?md5=4e9a54c3bc27837b474f34dc47844f58&pid=1-s2.0-S2772369024000501-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142272232","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