Additive manufacturing letters最新文献_第3页

On the use of slurry as an alternative to dry powder for laser powder bed fusion of 316L stainless steel 在 316L 不锈钢激光粉末床熔化中使用浆料替代干粉

IF 4.2

Additive manufacturing letters Pub Date : 2024-08-17 DOI: 10.1016/j.addlet.2024.100230

{"title":"On the use of slurry as an alternative to dry powder for laser powder bed fusion of 316L stainless steel","authors":"","doi":"10.1016/j.addlet.2024.100230","DOIUrl":"10.1016/j.addlet.2024.100230","url":null,"abstract":"<div><p>Laser powder bed fusion (LPBF) is a well-established additive manufacturing process for producing high-quality metal components with unparallelled design freedom. However, LPBF also has its limitations, including a limited materials palette, low productivity and high costs, mainly due to the expensive feedstock powders. These powders must meet highly stringent requirements regarding particle size (15–<span><math><mrow><mn>45</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span>), particle size distribution (mono-modal) and morphology (spherical), which is achievable only through expensive gas- and plasma-atomised powders. This paper investigates slurry-LPBF as an alternative to conventional dry powder LPBF. The use of slurry removes some of the stringent powder requirements by allowing deposition of smaller particles with a variety of particle morphologies. Slurry-LPBF can therefore increase the useful yield of the atomisation process and expand the materials palette for LPBF, by enabling the use of powders for which atomised variants are not commercially available. This study used 316L stainless steel powder with an average particle size <span><math><mrow><mo><</mo><mn>18</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span>. An existing slurry-LPBF machine was re-designed and re-built, allowing successful slurry processing. Two optimal parameter sets were obtained, resulting in component density of 99.4%. Tensile testing revealed an ultimate tensile strength (UTS) of 622 ± 2 MPa and an elongation at break of 66 ± 2%. These results are consistent, and fall within the range of reported values in literature for dry-powder LPBF, with the UTS being on the lower side of the range, whilst elongation at break being on the higher side.</p></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772369024000380/pdfft?md5=5e6b605faf1666b404a4bcade4865925&pid=1-s2.0-S2772369024000380-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142048633","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

Economics of 3D printing ceramic cores for gas turbine investment castings 三维打印燃气轮机熔模铸造陶瓷芯的经济性

IF 4.2

Additive manufacturing letters Pub Date : 2024-07-01 DOI: 10.1016/j.addlet.2024.100223

Eduardo Maristany , Zachary C. Cordero , Jesse Boyer , Lynnora O. Grant

{"title":"Economics of 3D printing ceramic cores for gas turbine investment castings","authors":"Eduardo Maristany , Zachary C. Cordero , Jesse Boyer , Lynnora O. Grant","doi":"10.1016/j.addlet.2024.100223","DOIUrl":"https://doi.org/10.1016/j.addlet.2024.100223","url":null,"abstract":"<div><p>Recent supply chain issues affecting the airfoil casting industry have renewed interest in industrial-scale 3D printing of ceramic cores. Ceramic cores are conventionally manufactured through injection molding. However, injection molding of low-volume production runs can be challenging because of the long lead times and high costs associated with mold tooling. 3D printing can mitigate up-front tooling costs, but there are other trade-offs, e.g., higher material costs of 3D printing feedstocks. Here, we develop a techno-economic model that accounts for costs (materials, tooling, equipment), core size, experience curve effects, and other important variables to determine threshold production volumes for which 3D printing is less expensive than conventional processing techniques. Using market data from 2019, our analysis shows that 3D printing a single dedicated core design with typical dimensions for aeroengine applications is less expensive than injection molding below ∼1,800 units. By simultaneously printing multiple core designs, this threshold increases to 120,000 units, or approximately 2 % of the 2019 aeroengine market demand. This threshold value decreases with increasing core size, indicating 3D printing is less favorable for large castings used in industrial gas turbines. These results are compared against the demand for ceramic cores in engine development, engine sustainment, and new engine manufacturing.</p></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772369024000318/pdfft?md5=513763866f7c987f0368cd3cd50d5036&pid=1-s2.0-S2772369024000318-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141595178","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

Reproducing wrought grain structure in additive IN718 through nanosecond laser induced cavitation 通过纳秒激光诱导空化再现添加剂 IN718 中的锻造晶粒结构

IF 4.2

Additive manufacturing letters Pub Date : 2024-07-01 DOI: 10.1016/j.addlet.2024.100229

{"title":"Reproducing wrought grain structure in additive IN718 through nanosecond laser induced cavitation","authors":"","doi":"10.1016/j.addlet.2024.100229","DOIUrl":"10.1016/j.addlet.2024.100229","url":null,"abstract":"<div><p>Pulsed laser assisted additive manufacturing has been demonstrated as a promising technology for controlling grain structure in 3D-printing processes. The integration of a nanosecond laser onto a wire arc additive manufacturing tool has enabled the localized printing of Inconel 718 with grain sizes meeting ASTM 9 standards (average measured grain size of <span><math><mrow><mn>13</mn><mo>.</mo><mn>7</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span>) for wrought material within a single bead under solidification conditions that would otherwise produce <span><math><mrow><mn>340</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span> columnar grains. The observed grain refinement holds promise, provided scale up is possible, for overcoming the highly anisotropic mechanical properties and microcracking associated with large columnar grains of Inconel 718 that have long stood in the way of leveraging the advantages of direct energy deposition printing techniques of difficult to machine alloys. Experiments on large bead sizes allowed for decoupling surface versus bulk nanosecond laser/liquid metal interaction mechanisms to determine that the source of the observed grain refinement is the collapse of cavitation bubbles originating from acoustic waves generated by momentum transfer into the melt of an ablation plasma. Additionally, experiments that increased the cavitation bubble density within the mushy zone during solidification by tuning the nanosecond laser scan path went beyond the 25 times reduction in grain size to a 70 times factor of refinement with a minimum average grain diameter approaching <span><math><mrow><mn>4</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span>.</p></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772369024000379/pdfft?md5=ada98bcd10763fcf7aecb0356eb93822&pid=1-s2.0-S2772369024000379-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141993039","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

Tracking the chemical composition of 3D printed 94 % alumina during the thermal post-process 在热后处理过程中跟踪 3D 打印 94% 氧化铝的化学成分

IF 4.2

Additive manufacturing letters Pub Date : 2024-07-01 DOI: 10.1016/j.addlet.2024.100225

引用次数: 0

Interpenetrating microstructure in laser powder-bed fusion parts using selective rescanning 利用选择性重扫描技术研究激光粉末床熔融部件中的穿透微观结构

IF 4.2

Additive manufacturing letters Pub Date : 2024-07-01 DOI: 10.1016/j.addlet.2024.100221

Bharath Bhushan Ravichander , Shweta Hanmant Jagdale , Golden Kumar

{"title":"Interpenetrating microstructure in laser powder-bed fusion parts using selective rescanning","authors":"Bharath Bhushan Ravichander , Shweta Hanmant Jagdale , Golden Kumar","doi":"10.1016/j.addlet.2024.100221","DOIUrl":"https://doi.org/10.1016/j.addlet.2024.100221","url":null,"abstract":"<div><p><em>In-situ</em> microstructural control is desirable in additively manufactured metal parts due to limited post-processing options for net-shaped components. Here, we introduce a novel selective rescanning approach to control the local solidification conditions and the microstructure in metal parts produced by laser powder-bed fusion (LPBF). We show that the melt pool dimensions, grain size, and sub-grain cell structure can be selectively varied in three dimensions to engineer the mechanical response of LPBF parts. The lattice-based rescanning strategy enables the formation of an interpenetrating microstructure comprised of fine and coarse grains. The localized heating and cooling-induced thermal stresses increase the hardness and tensile strength of rescanned specimens. The study shows the potential of selective rescanning strategy as a promising avenue for achieving precise control of microstructure and properties in as-printed LPBF parts without subsequent processing.</p></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772369024000306/pdfft?md5=a3c097750235487cc665b24857531d36&pid=1-s2.0-S2772369024000306-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141480277","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

GRCop-42: Comparison between laser powder bed fusion and laser powder direct energy deposition GRCop-42：激光粉末床熔融与激光粉末直接能量沉积的比较

IF 4.2

Additive manufacturing letters Pub Date : 2024-07-01 DOI: 10.1016/j.addlet.2024.100224

引用次数: 0

Printing vertical flat surfaces in thermoset big area additive manufacturing 在热固性大面积增材制造中打印垂直平面

IF 4.2

Additive manufacturing letters Pub Date : 2024-07-01 DOI: 10.1016/j.addlet.2024.100226

{"title":"Printing vertical flat surfaces in thermoset big area additive manufacturing","authors":"","doi":"10.1016/j.addlet.2024.100226","DOIUrl":"10.1016/j.addlet.2024.100226","url":null,"abstract":"<div><p>In extrusion-based additive manufacturing, achieving high surface quality typically involves using small layer heights to reduce the size of grooves between layers. However, this approach can be both less effective and time-consuming in big-area additive manufacturing. Therefore, the current focus is on investigating methods for printing with fewer layers without compromising surface quality. In this study, single-strand walls were printed using a two-component thermoset material, where different nozzle designs and printing strategies are explored to achieve the flattest possible surface. The success of each approach was evaluated by measuring the percentage of material that required removal to achieve a perfect vertical flat wall. The results suggested that incorporating vertical wings to contain the material in the desired shape was beneficial. Furthermore, the study introduced the idea of adjustable layer heights to mitigate layer deformation. This deformation is most noticeable in the initial layers but largely affects all subsequent printed layers. Finally, making the wings have an angle with regard to the printing direction or trapezoidal wings, served as a pressure funnel that produced the greatest improvement in surface quality. These changes allowed for a reduction of the amount of material which would need to be removed to achieve a flat wall without grooves from 14.3% for a standard print from a round nozzle, to 2.5% for an optimized strand. The research shows a promising path to producing entirely flat vertical structures, even when printing with still-deformable, thermoset materials in the context of big-area additive manufacturing.</p></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772369024000343/pdfft?md5=f3dc57a6059c196a163df977d90f95a8&pid=1-s2.0-S2772369024000343-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141850721","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

Oxidation behavior of Cu–Ag alloy in-situ manufactured via laser powder bed fusion 通过激光粉末床熔化原位制造的铜银合金的氧化行为

IF 4.2

Additive manufacturing letters Pub Date : 2024-07-01 DOI: 10.1016/j.addlet.2024.100228

引用次数: 0

Microstructure and mechanical response of as-built and solution-annealed LPBF Hastelloy X under high-temperature fatigue loading 坯料和固溶退火 LPBF 哈氏合金 X 在高温疲劳载荷下的微观结构和机械响应

IF 4.2

Additive manufacturing letters Pub Date : 2024-07-01 DOI: 10.1016/j.addlet.2024.100227

{"title":"Microstructure and mechanical response of as-built and solution-annealed LPBF Hastelloy X under high-temperature fatigue loading","authors":"","doi":"10.1016/j.addlet.2024.100227","DOIUrl":"10.1016/j.addlet.2024.100227","url":null,"abstract":"<div><p>This study investigates the microstructural characteristics and the high-temperature mechanical behavior of Hastelloy X, fabricated via laser powder-bed fusion (LPBF) technology. Hastelloy X, a solid solution-strengthened nickel-based superalloy known for its high strength and oxidation resistance at elevated temperatures, has gained significant interest for the fabrication of complex aerospace components through LPBF technology. The study initially focuses on the impact of solution annealing heat treatment at 1227 °C on the alloy microstructure, based on scanning electron microscopy (SEM) and transmission electron microscopy (TEM) investigations. It then explores the fatigue and cyclic deformation response of the alloy at 750 °C across different strain ranges, comparing the as-built and solution-annealed conditions. To understand the observed differences in the cyclic mechanical response of as-built and solution-annealed LPBF HX, for a particular condition, a set of dedicated tests have been performed and interrupted at selected numbers of cycles in the different stages of the mechanical response. At each interruption point, specimens have been examined by TEM to provide an in-depth understanding of the effect of dislocation microstructural evolution on the high-temperature cyclic mechanical response of the alloy.</p></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":null,"pages":null},"PeriodicalIF":4.2,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772369024000355/pdfft?md5=3e6d8516fe09fdcae1e1cd847567a059&pid=1-s2.0-S2772369024000355-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141846392","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

Extracting powder bed features via electron optical images during electron beam powder bed fusion 通过电子束粉末床融合过程中的电子光学图像提取粉末床特征

Additive manufacturing letters Pub Date : 2024-05-07 DOI: 10.1016/j.addlet.2024.100220

Matthias Markl, Mohammad Reza Azadi Tinat, Timo Berger, Jakob Renner, Carolin Körner

{"title":"Extracting powder bed features via electron optical images during electron beam powder bed fusion","authors":"Matthias Markl, Mohammad Reza Azadi Tinat, Timo Berger, Jakob Renner, Carolin Körner","doi":"10.1016/j.addlet.2024.100220","DOIUrl":"https://doi.org/10.1016/j.addlet.2024.100220","url":null,"abstract":"<div><p>Electron beam powder bed fusion offers the unique opportunity to observe the process by measuring scattered electrons on a metal detector. This technique is the state of the art in generating electron optical images of the build area after melting using single- or multi-detector setups. The images enable the detection of surface defects like porosity or material transport by reconstructing the surface topography. Internal defects such as layer-bonding defects cannot be identified. Many of these defects, particularly layer-bonding defects, often originate from an irregular distribution of the powder bed.</p><p>This work introduces an additional process step by recording an electron optical image after the distribution of the powder bed. Combining this with an electron optical image after melting the previous layer enables extraction of powder bed features such as the current powder bed height. The underlying method bases on the correlation of experimental measurements and numerical simulations of the intensity of the electron optical signal for different powder bed heights. With this approach, it is possible to identify irregular powder distributions, such as uncovered areas of previously molten material or locally varying powder bed heights. This information is crucial for online monitoring and real time process control. Exemplary, this opens the opportunity of healing the powder bed by an additional raking step.</p></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S277236902400029X/pdfft?md5=bcfec8a21ec24fa6bea53ac48b89eac6&pid=1-s2.0-S277236902400029X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140918694","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