Additive manufacturing最新文献

{"title":"Interfacial characterization and bonding performance of additively manufactured GH4169/cast iron bimetal","authors":"Yixuan Fu,&nbsp;Jinxiang Liu,&nbsp;Weiqing Huang,&nbsp;Yungui Liu","doi":"10.1016/j.addma.2024.104429","DOIUrl":"10.1016/j.addma.2024.104429","url":null,"abstract":"<div><div>Bimetal has excellent potential for high-power density cylinder heads due to its design flexibility, functionality, and economy. Interfacial characterization and bonding performance affect the reliability of the bimetal in service. In this paper, the GH4169/cast iron bimetal has been manufactured by the Laser Powder Bed Fusion (L-PBF). The morphology, microstructure, and phases of the GH4169/cast iron bimetallic bonding interface were characterized, and the element distribution was analyzed qualitatively and quantitatively. The nano-hardness and nano-elastic modulus of the GH4169/cast iron bimetallic bonding interface were tested. Shear tests were used to characterize the bonding strength of the GH4169/cast iron bimetallic bonding interface. The results show that the bonding interface of the GH4169/cast iron bimetal is wavy and shows excellent metallurgical bonding. Traces of cyclic flow formed at the bonding interface due to the low energy density and the rapid solidification rate of the molten pool, which prevent the elements from mixing and diffusing sufficiently. As the energy density increases, the traces of cyclic flow at the bonding interface gradually decrease, and the width of the bimetallic diffusion zone (DZ) grows. The bonding of the GH4169/cast iron bimetal is mainly accompanied by the melting and diffusion of Ni, Fe, and C elements to form Ni–Fe compounds, carbides, etc. Spearman correlation analysis reveals that the shear strength shows an apparent positive correlation with the nano-hardness of the DZ, and higher nano-hardness of the DZ improves the bonding strength of the bimetallic bonding interface. The morphology, element distribution, and properties of the bonding interface are all factors that affect the bonding performance. This study can provide data support and a theoretical basis for applying the GH4169/cast iron bimetal from the material to the structural level.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":null,"pages":null},"PeriodicalIF":10.3,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142315649","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":"Investigation of the humidity control in the printing space for the material extrusion of medical biodegradable hydrogel","authors":"Kaicheng Yu ,&nbsp;Qiang Gao ,&nbsp;Yifeng Yao ,&nbsp;Zexue Lin ,&nbsp;Peng Zhang ,&nbsp;Lihua Lu","doi":"10.1016/j.addma.2024.104452","DOIUrl":"10.1016/j.addma.2024.104452","url":null,"abstract":"<div><div>Materials extrusion for medical biodegradable hydrogel manifests potential for the fabrication of biomimetic functionalized tissues in tissue engineering. However, the uncontrollable shape of 3D printed structures usually leads to shrinkage as well as collapse of the prepared biocompatible scaffold, which limits the potential to develop large-size tissue or organs. Uncontrollable ambient humidity during the 3D printing process is a primary cause of the moisture loss and geometric variation of prepared architectures, which means the humidity in the printing space of hydrogel materials must be controlled accurately throughout the extrusion process. This study proposed a novel configuration of humidity-controlled atmospheric enclosure, by which the humidity distribution in the printing space can be accurately regulated. Subsequently, a fluid-thermal-humidity coupling field simulation model based on the finite element method was established to numerically investigate the humidity field in the printing space. Furthermore, printing trials were conducted with the proposed atmospheric enclosure, and the moisture loss of 3D architecture was avoided. The size of the scaffold was improved evidently from 25 mm(length) × 25 mm(width) × 0.6 mm(height) to 25 mm(length) × 25 mm(width) × 3.5 mm(height).</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":null,"pages":null},"PeriodicalIF":10.3,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142315586","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: “In-situ tailoring microstructures to promote strength-ductility synergy in laser powder bed fusion of NiCoCr medium-entropy alloy” [Addit. Manuf., 66 (2023) 103443]","authors":"Kexuan Zhou,&nbsp;Dingcong Cui,&nbsp;Zishu Chai,&nbsp;Yashan Zhang,&nbsp;Zhongsheng Yang,&nbsp;Chao Zhu,&nbsp;Zhijun Wang,&nbsp;Junjie Li,&nbsp;Jincheng Wang","doi":"10.1016/j.addma.2024.104413","DOIUrl":"10.1016/j.addma.2024.104413","url":null,"abstract":"","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":null,"pages":null},"PeriodicalIF":10.3,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357119","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":"Deciphering mechanical heterogeneity of additively manufactured martensitic steel using high throughput nanoindentation combined with machine learning","authors":"Ankita Roy ,&nbsp;Abhijeet Dhal ,&nbsp;Clara Mock ,&nbsp;B.A. McWilliams ,&nbsp;K.C. Cho ,&nbsp;Rajiv S. Mishra","doi":"10.1016/j.addma.2024.104408","DOIUrl":"10.1016/j.addma.2024.104408","url":null,"abstract":"<div><p>Microstructures of additively manufactured (AM) materials are highly heterogeneous, periodic, and hierarchical at various length scales, leading to complex mechanical response. In this study, nanoindentation trend analysis combined with machine learning (ML) was used to unravel the hierarchical and heterogeneous microstructures and associated multiscale mechanical responses in a laser-directed energy deposited low-alloy martensitic steel. At length scale encompassing several melt pools, periodic hardness fluctuations were attributed to variation in strain accommodation and phase transformation during primary solidification and thermal reheat cycles between the melt pools. The observed trends were a net balance between dislocation accumulation due to volume contraction during liquid to austenite solidification, and relaxation due to subsequent solid-state martensitic transformation during cooling. The hardness trends within a single melt pool (250–300 µm) were ascribed to cooling rate variations which manifests in form of changes in primary dendritic arm spacing. The inter-dendritic regions enriched with Cr and Mo demonstrated higher elastic modulus and hardness. In microstructural scale, variation in pop-in behavior in the nanoindentation load-displacement (<em>P-h</em>) curves was correlated to local microstructural heterogeneity in the indenter-material interaction volume (dendritic segregation + martensite matrix) using various ML-based classification techniques: decision tree, support vector machine and neural network. It classified the indentations into three broad categories: first set showing only one pop-in lying within the segregation channel with 10,000 &lt;<em>P/h</em>&lt; 13,000 N/m, while the second set with <em>P/h</em> &lt;10,000 N/m lied on the matrix and third set with <em>P/h</em> &gt;13,000 N/m with multiple popins lied on the matrix-segrgeation interface. This novel multimodal structure-property correlative framework, integrating nanoindentation trend analysis with ML, provides a high-throughput approach to unravel the complex mechanical behavior of AM materials across multiple length scales, representing a key advancement in the field.</p></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":null,"pages":null},"PeriodicalIF":10.3,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142164687","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":"Digital light processing 3D printing of porous ceramics: A systematic analysis from a debinding perspective","authors":"Insup Kim ,&nbsp;Yong-Jin Yoon","doi":"10.1016/j.addma.2024.104409","DOIUrl":"10.1016/j.addma.2024.104409","url":null,"abstract":"<div><p>Using 3D printing technologies in manufacturing ceramic structures has received much attention. The requirements for advancing these technologies, especially vat photopolymerization, include segmented steps such as the optimization of ceramic suspension, the process parameters of 3D printing, and the thermal treatment conditions. Although 3D printing for dense ceramics has been studied extensively, more is needed to optimize 3D printing processes for fabricating porous ceramics. Mainly because the pore properties of porous ceramics determine their performance, an in-depth investigation is needed to determine how the thermal treatment conditions control these pore properties. To bridge this gap, in this study, ceramic (lead zirconate titanate) green bodies embedding pore-forming agents (polymethylmethacrylate) were fabricated by DLP (Digital Light Processing) 3D printing. They were debinded in a vacuum atmosphere at different heating rates (0.5, 1, and 2℃/min) for fabricating porous ceramics. These processes were followed by air debinding and sintering steps. Our findings revealed that the optimal heating rate condition produces the lowest shrinkages, surface roughness, and an improved stair effect. More importantly, this optimal condition led to porous ceramics without cracks and with pores that matched well with the size distribution of the pore-forming agent, which was used as a starting material. This systematic approach can be extended to combinations of various types of ceramics and pore-forming agents. Therefore, this study provides a guideline for determining the optimal heating rate condition to manufacture porous ceramics by DLP 3D printing technology.</p></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":null,"pages":null},"PeriodicalIF":10.3,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142230601","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":"New experimental approach for local measurements of effective layer thickness, powder bed density and volumetric energy density to enhance metal laser powder bed fusion","authors":"Filippo Zanini,&nbsp;Nicolò Bonato,&nbsp;Simone Carmignato","doi":"10.1016/j.addma.2024.104432","DOIUrl":"10.1016/j.addma.2024.104432","url":null,"abstract":"<div><p>This work presents an experimental approach for simultaneous measurements of effective layer thickness, powder bed density, and volumetric energy density, useful to improve the analysis of process dynamics and enhance precision in metal laser powder bed fusion. The approach is based on a special building platform, including removable inserts with reference geometries, and high-resolution X-ray computed tomography. The local variability in layer thickness and energy density are evaluated and used as indicators of process stability and energy transmission efficiency. The contextual measurement of powder bed density offers additional insights into potential process-related influences such as spatter formation and denudation.</p></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":null,"pages":null},"PeriodicalIF":10.3,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142242547","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":"Data-driven prediction of future melt pool from built parts during metal additive manufacturing","authors":"Yaohong Xiao ,&nbsp;Xiantong Wang ,&nbsp;Wenhua Yang ,&nbsp;XinXin Yao ,&nbsp;Zhuo Yang ,&nbsp;Yan Lu ,&nbsp;Zhuo Wang ,&nbsp;Lei Chen","doi":"10.1016/j.addma.2024.104438","DOIUrl":"10.1016/j.addma.2024.104438","url":null,"abstract":"<div><div>Smart manufacturing in metal additive manufacturing (MAM) relies on real-time process optimization through the prediction of unbuilt parts using data from built parts. Melt pool dynamics are intimately associated with the development of various microstructures during the MAM. In this paper, we demonstrate the idea by establishing a machine learning (ML) model to predict the melt pool of future parts, based on the experimental data from the National Institute of Standards and Technology (NIST) where 80 % is used for the training (built parts) and 20 % for testing (future parts). The ML model integrates both data denoising and predictive modeling. First, a convolutional neural network (CNN) is used to process a large dataset of raw melt pool images, enabling the automatic removal of noises (e.g., splash and plume) and thereof extraction of high-quality melt pool data. Following that, a novel data-driven melt pool model based on multi-layer perceptron (MLP) is trained by incorporating raw, long scanning history as input features, which best accounts for the effects of printing history (e.g., intertrack heating) on melt pool development. It takes complete advantage of MLP in handling high-dimensional regression problems in conjunction with a large dataset. Upon testing under various manufacturing conditions, the average relative error magnitude (AREM) of predicting melt pool size drops to 2.8 %, compared to 14.8 % of the prior art – the Neighboring Effect Modeling Method model (NBEM). This research thus represents a significant step towards reliable melt-pool-guided AM process optimization for smart manufacturing, enabled by advanced, flexible, and maximum use of ML techniques.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":null,"pages":null},"PeriodicalIF":10.3,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142315587","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":"Enhancing the fracture resistance of additive manufactured polylactic acid via Morse-code-like architecturing","authors":"Deepesh Yadav,&nbsp;Balila Nagamani Jaya","doi":"10.1016/j.addma.2024.104418","DOIUrl":"10.1016/j.addma.2024.104418","url":null,"abstract":"<div><div>Additively manufactured poly-lactic acid (PLA) suffers from a limited fracture resistance. In this study, a combination of circular hole (dot) and elliptical hole (dash) architectures inspired from the Morse-Code are incorporated into (PLA) through additive manufacturing (AM) to improve their fracture resistance. The circular hole-like (C) features work as crack arrestors and the elliptical hole-like (E) features work as crack deflectors. A combination of simulations and experiments are performed to quantifiably determine the effect of single feature, double features, and other tailored arrangements of these features on the crack driving force and fracture resistance using elastic-plastic fracture mechanics. All the AM architecture systems show a significantly higher fracture resistance compared to the bulk AM PLA. Amongst the various systems tested, both the initiation work of fracture and total work of fracture are found to be the highest for alternative layers of E-C features. A 1172 % increase is observed from initiation to total work of fracture for the EC architecture, which is reflected in the fracture resistance curve (<em>R</em>-curve). This has important applications in the structural integrity and life of biomedical systems made from PLA. The applicability of work of fracture and conventional fracture mechanics for additively manufactured, architected systems with significant crack tip plasticity is also discussed.</div></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":null,"pages":null},"PeriodicalIF":10.3,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142315754","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":"Optical tomography by laser line scanning and digital twinning for in-process inspection of lattice structures in material extrusion","authors":"Michele Moretti,&nbsp;Arianna Rossi,&nbsp;Nicola Senin","doi":"10.1016/j.addma.2024.104424","DOIUrl":"10.1016/j.addma.2024.104424","url":null,"abstract":"<div><p>One of the challenges of manufacturing hollow parts featuring internal lattice structures by using material extrusion is to achieve geometric accuracy of the internal geometries. In this work a solution for in-process geometric inspection and monitoring is presented, based on combining on-machine part measurement by laser line scanning and digital twinning. In the solution, a laser line scanner is used to acquire a two-dimensional map of material and void distribution within the deposited layer. Layer inspection is carried out by comparing the 2D map with a reference one obtained by simulating the deposition process (digital twin of the layer); discrepancies are automatically identified and quantified. The evolution of anomalies across layers can be tracked by vertically stacking both layer measurements and 2D digital twins and by investigating the resulting 3D voxel models. The models are updated after the fabrication of each new layer, to allow geometric monitoring over time. The proposed inspection and monitoring solution is particularly suitable for hollow parts and/or lattice or otherwise reticular internal structures, which would otherwise be inaccessible when using conventional measurement methods on the final part.</p></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":null,"pages":null},"PeriodicalIF":10.3,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142230602","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":"Mechanism of grain boundary angle on solidification cracking in directed energy deposition Hastelloy X superalloys","authors":"Yashan Zhang,&nbsp;Bojing Guo,&nbsp;Meirong Jiang,&nbsp;Junjie Li,&nbsp;Zhijun Wang,&nbsp;Lei Wang,&nbsp;Jincheng Wang,&nbsp;Xin Lin","doi":"10.1016/j.addma.2024.104406","DOIUrl":"10.1016/j.addma.2024.104406","url":null,"abstract":"<div><p>Solidification cracking occurs only when the grain boundary (GB) angle (<span><math><mi>θ</mi></math></span>) exceeds a critical value. This value, known as the critical cracked GB angle (<span><math><msup><mrow><mi>θ</mi></mrow><mrow><mo>*</mo></mrow></msup></math></span>), can be predicted from the grain coalescence theory based on GB-angle-dependent GB energy. However, the calculated value (<span><math><msubsup><mrow><mi>θ</mi></mrow><mrow><mi>c</mi></mrow><mrow><mo>*</mo></mrow></msubsup></math></span>) is always less than the measured value in experiments (<span><math><msubsup><mrow><mi>θ</mi></mrow><mrow><mi>e</mi></mrow><mrow><mo>*</mo></mrow></msubsup></math></span>), which is also confirmed in our directed energy deposition Hastelloy X superalloys. In addition to GB energy, there are evidences showing that GB angle can affect cracking by changing dendrite spacings. We show by experiments and phase field simulations that, same as GB energy, the dendrite spacings at GBs increase with GB angle, but its effect on solidification cracking sensitivity (SCS) is opposite to GB energy. Depending on their relative contributions, three ranges can be identified. In the first range of <span><math><mrow><mi>θ</mi><mo>&lt;</mo><msubsup><mrow><mi>θ</mi></mrow><mrow><mi>c</mi></mrow><mrow><mo>*</mo></mrow></msubsup></mrow></math></span>, both dendrite spacings and GB energy have negligible effects on dendrite coalescence, compared to the case inside a grain. In the second range of <span><math><mrow><msubsup><mrow><mi>θ</mi></mrow><mrow><mi>c</mi></mrow><mrow><mo>*</mo></mrow></msubsup><mo>&lt;</mo><mi>θ</mi><mo>&lt;</mo><msubsup><mrow><mi>θ</mi></mrow><mrow><mi>e</mi></mrow><mrow><mo>*</mo></mrow></msubsup></mrow></math></span>, dendrite spacings counteract the effect of high GB energy on SCS. It is exactly this effect that induces the gap in <span><math><msup><mrow><mi>θ</mi></mrow><mrow><mo>*</mo></mrow></msup></math></span> between theory and experiments. In the third range of <span><math><mrow><mi>θ</mi><mo>&gt;</mo><msubsup><mrow><mi>θ</mi></mrow><mrow><mi>e</mi></mrow><mrow><mo>*</mo></mrow></msubsup></mrow></math></span>, GB energy plays a dominant role and leads to severe solidification cracking. After including the effect of dendrite spacings on SCS, we predict <span><math><msup><mrow><mi>θ</mi></mrow><mrow><mo>*</mo></mrow></msup></math></span>=15° in directed energy deposition Hastelloy X superalloys, close to the experimental value of 18°. These new findings provide new insights for suppressing cracking by controlling the dendrite spacings near GBs.</p></div>","PeriodicalId":7172,"journal":{"name":"Additive manufacturing","volume":null,"pages":null},"PeriodicalIF":10.3,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142149601","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}