Additive manufacturing letters最新文献

{"title":"Fabrication of ultra-thin porous titanium alloys by electron beam selective melting: Porosity and mechanical properties","authors":"Jinhu Liu ,&nbsp;Feihong Wang ,&nbsp;Dong Lu ,&nbsp;Yongfeng Liang ,&nbsp;Junpin Lin","doi":"10.1016/j.addlet.2025.100268","DOIUrl":"10.1016/j.addlet.2025.100268","url":null,"abstract":"<div><div>Titanium alloys are widely regarded as ideal biomaterials due to their superior mechanical properties and resistance to corrosion. Additive manufacturing offers a novel approach for fabricating porous structures, enabling the production of titanium alloys with intricate geometries and varied dimensions. In this study, porous titanium alloys were produced using the Ti-6Al-2Zr-2V-1Mo alloy via electron beam selective melting (EBSM). Thin-wall structures with thicknesses ranging from 360 μm to 600 μm demonstrated exceptional mechanical performance near the forming threshold. An increase in porosity from 22 % to 32 % was observed, resulting in a reduction in tensile strength from 350 MPa to 250 MPa. Tensile testing and microstructural analyses revealed that precise control of the electron beam spot diameter facilitated effective metallurgical bonding between powder particles, with residual pores comparable in size to the original powder. This work highlights a promising strategy for fabricating titanium alloys tailored for biomedical applications.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"13 ","pages":"Article 100268"},"PeriodicalIF":4.2,"publicationDate":"2025-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143148820","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}

{"title":"Hot forming behavior of tungsten carbide reinforced Ni-Based superalloy 625 additively manufactured by laser directed energy deposition","authors":"Gökhan Ertugrul ,&nbsp;Aliakbar Emdadi ,&nbsp;Angelika Jedynak ,&nbsp;Sabine Weiß ,&nbsp;Sebastian Härtel","doi":"10.1016/j.addlet.2025.100267","DOIUrl":"10.1016/j.addlet.2025.100267","url":null,"abstract":"<div><div>The demands of high-performance industries such as aerospace, automotive, tool manufacturing, oil, and gas industries are driving the innovation in high-performance materials and their production methods. This study explores the impact of hybrid manufacturing, specifically the effect of the addition of tungsten carbide (WC/W2C) via Laser-Directed Energy Deposition (L-DED), on the hot workability, hardness, and microstructure of nickel-based superalloy Inconel 625 (IN625). IN625 is known for its high temperature and high corrosion resistance, and tungsten carbide for its high wear resistance and grain refinement effect. The integration of WC/W2C particles into the IN625 matrix, in addition to the use of the hybrid approach of additive manufacturing followed by a hot–forming process, significantly influences the microstructure and mechanical behavior of the material. Thus, while incorporation of the WC/W2C can strengthen the material and extend the mechanical limitations, its full impact, including any potential usages, should be thoroughly evaluated for the intended application of the materials. To understand the effect of WC/W2C, additive manufacturing of IN625 both with and without WC/W2C and isothermal hot compression was carried out. The objective is to analyze the differences in microstructure and properties between <span>L</span>-DED manufactured IN625, and WC-reinforced IN625, and their hot-forming behavior, focusing on the effects of WC addition and post-deformation on microstructure and mechanical properties. This work represents the first investigation into the effect of WC/W2C hard particles on the hot-forming process of additively manufactured Ni-based metal matrix composites.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"13 ","pages":"Article 100267"},"PeriodicalIF":4.2,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143098795","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}

{"title":"On the damping and fatigue characterization of additively manufactured Ti-6Al-4V","authors":"Peyton J. Wilson ,&nbsp;Elaheh Azizian-Farsani ,&nbsp;Mikyle Paul ,&nbsp;Michael M. Khonsari ,&nbsp;Shuai Shao ,&nbsp;Nima Shamsaei","doi":"10.1016/j.addlet.2024.100260","DOIUrl":"10.1016/j.addlet.2024.100260","url":null,"abstract":"<div><div>With the recent implementation of additively manufactured parts into industrial applications, there is a dire need for nondestructive evaluation methods to qualify if these components are fit for service due to their sensitivity to processing conditions. The Impulse Excitation Technique (IET) is applied to additively manufactured Ti-6Al-4V bending specimens to determine natural frequencies and damping properties in order to predict fatigue performance relative to specimens fabricated with different processing parameters. From the damping and natural frequency results, it was found that the specimens, fabricated with intentional underheating to induce lack of fusion defects, had the lowest damping value in the pristine condition and the highest natural frequency. For the three batches of specimens tested, it was determined that the underheated specimens had the best fully-reversed bending fatigue performance with the highest fatigue limit (297 MPa) and longest fatigue lives as compared to the other two batches, implying a relation of decreased fatigue life with increased material damping in the pristine condition. The theory of the IET related to materials is presented with damping and fatigue results, as well as microstructural analysis and fractography of three specimens batches fabricated with different processing parameters.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"11 ","pages":"Article 100260"},"PeriodicalIF":4.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143148337","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}

{"title":"Molten metal jetting for repairing aluminum components","authors":"Benedikt Kirchebner ,&nbsp;Kellen D. Traxel ,&nbsp;Alexander E. Wilson-Heid ,&nbsp;Eric S. Elton ,&nbsp;Andrew J. Pascall ,&nbsp;Jason R. Jeffries","doi":"10.1016/j.addlet.2024.100259","DOIUrl":"10.1016/j.addlet.2024.100259","url":null,"abstract":"<div><div>Molten metal jetting (MMJ) is an additive manufacturing (AM) method where droplets of molten metal are used to build parts. Like most AM technologies, MMJ is typically used to build stand-alone parts rather than add onto existing parts. However, the droplet-wise deposition method of MMJ is inherently compatible with the ability to build on existing parts. Here, we utilize MMJ to “repair” machined damage on cast aluminum parts. A commercial MMJ system was used to fill in varied but defined groove geometries to find optimal shapes amenable to repair with MMJ. Subsequently, grooves were cut into tensile specimens and back-filled (repaired) using MMJ. Tensile tests indicate that MMJ repair restores significant strength to samples despite the distinct microstructure and void structures present in the repaired section. Repaired samples demonstrated tensile strengths ∼72 % of the as-received material, compared to UTS of ∼33 % for damaged samples. These results indicate that MMJ is a viable method to repair parts where other repair methods may be impractical.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"11 ","pages":"Article 100259"},"PeriodicalIF":4.2,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143148355","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}

{"title":"Additive manufacturing simulations: An approach based on space partitioning and dynamic 3D mesh adaptation","authors":"Panagis Foteinopoulos,&nbsp;Alexios Papacharalampopoulos,&nbsp;Panagiotis Stavropoulos","doi":"10.1016/j.addlet.2024.100256","DOIUrl":"10.1016/j.addlet.2024.100256","url":null,"abstract":"<div><div>Simulation is one of the most widely used methods for process optimization towards improved part quality in Additive Manufacturing (AM), particularly for metal parts. However, due to the nature of the AM processes and the complex phenomena that occur, simulations that are capable of providing a detailed overview of the physical mechanisms demand considerable computational resources and time. In this study, a numerical approach is presented, which can be applied to any implicit numerical thermal simulation for AM, allowing for a significant decrease in computational time (higher than 70%) with minimal impact on accuracy. This is achieved by combining space partitioning, enabled by a boundary condition that was developed, with dynamic mesh adaptation in the <em>x</em>-, <em>y</em>-, and <em>z</em>-axis. The methodology is described in detail and both the decrease in computational time and the accuracy of the developed approach are validated in a computational case study, as well as using experimental results.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"11 ","pages":"Article 100256"},"PeriodicalIF":4.2,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702850","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}

{"title":"Understanding the effect of pre-sintering scanning strategy on the relative density of Zr-modified Al7075 processed by laser powder bed fusion","authors":"Nicolas Nothomb ,&nbsp;Ignacio Rodriguez-Barber ,&nbsp;María Teresa Pérez-Prado ,&nbsp;Norberto Jimenez Mena ,&nbsp;Grzegorz Pyka ,&nbsp;Aude Simar","doi":"10.1016/j.addlet.2024.100253","DOIUrl":"10.1016/j.addlet.2024.100253","url":null,"abstract":"<div><div>Only a limited aluminium material palette is currently available for L-PBF processing, especially for high strength aluminium alloy. Unmodified Al7075 suffers from hot cracking making it nearly impossible to process by L-PBF. Adding some grain refiner to Al7075 solves this issue of hot cracking. However, this alloy still presents difficulties to be processed with densities above 99.5%. In this study, the unconventional pre-sintering scanning strategy is applied to process 99.9% density Al7075+1.8%Zr. For this scanning strategy, each layer is scanned twice with different power, i.e. it is first scanned with half the power selected for the second scan. This specific strategy remelts potential defect generated by the first scan and reduces lack of fusion pores. These two phenomena lead to high density L-PBF Al7075+1.8%Zr and pave the way to higher densities for high strength aluminium alloys.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"11 ","pages":"Article 100253"},"PeriodicalIF":4.2,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702920","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}

{"title":"Area-based composition predictions of materials fabricated using simultaneous wire-powder-directed energy deposition","authors":"Scott C. Bozeman,&nbsp;O. Burkan Isgor,&nbsp;Julie D. Tucker","doi":"10.1016/j.addlet.2024.100254","DOIUrl":"10.1016/j.addlet.2024.100254","url":null,"abstract":"<div><div>Functionally graded materials are an emergent method for designing components with programmable site-specific material properties. These materials are typically fabricated using metal additive manufacturing tools by simultaneously feeding multiple wire and/or powder feedstocks at various rates to achieve spatial composition change. The wire-powder-directed energy deposition (WP-DED) technique is of particular interest for many functionally graded material applications by balancing the low raw materials cost of wire with the high resolution of powder. However, feeding wire and powder are inherently different processes since all extruded wire enters the melt pool, while much of the blown powder is scattered, which makes determining the composition of the build challenging. In this study, we devise a simple area-based measurement method for estimating the composition of WP-DED structures. WP-DED single beads are printed using 309L stainless steel wire and commercially pure Fe powder at five wire feed rates (0.5, 0.75, 1.00, 1.25, 1.50 mm/mm) and five powder feed rates (2, 4, 6, 8, 10 rpm). Characteristic defects including interface gaps and macrosegregation (lack of mixing) tendencies are examined. High powder feed rates (8, 10 rpm) result in interface gaps at all wire feed rates, but smooth deposition and complete mixing is achieved at low powder feed rates, particularly with lower wire feed rates as well. The area-based composition measurement method is within ±20% of energy dispersive x-ray spectroscopy measurements for all samples, showing its effectiveness as a rapid composition estimate for WP-DED materials development.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"11 ","pages":"Article 100254"},"PeriodicalIF":4.2,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656285","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}

{"title":"Modelling process monitoring data in laser powder bed fusion: A pragmatic route to additive manufacturing quality assurance","authors":"Luke N. Carter ,&nbsp;Victor M. Villapún ,&nbsp;James Andrews ,&nbsp;Thomas R.B. Grandjean ,&nbsp;John Dardis ,&nbsp;Sophie C. Cox","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 R²=0.8. Algorithm variable trends, supported by corresponding sensitivity analysis, identified two different behavioural regimes. Under low linear energy density (&lt;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":"11 ","pages":"Article 100252"},"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}

{"title":"Drop-on-demand 3D printing of programable magnetic composites for soft robotics","authors":"Anil Bastola ,&nbsp;Luke Parry ,&nbsp;Robyn Worsley ,&nbsp;Nisar Ahmed ,&nbsp;Edward Lester ,&nbsp;Richard Hague ,&nbsp;Christopher Tuck","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":"11 ","pages":"Article 100250"},"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}

{"title":"Enabling tailored microstructures by hybrid directed energy deposition processing of a nickel-based superalloy","authors":"Clemens Johannes Müller ,&nbsp;Klaus Büßenschütt ,&nbsp;Alexander Schwedt ,&nbsp;Johannes Henrich Schleifenbaum ,&nbsp;Markus Sudmanns","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":"11 ","pages":"Article 100248"},"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}