Modeling the track cross-sectional profile (CSP) in deposition processes is critical for assessing and controlling deposition quality. This article focuses on modeling time-invariant deposition (TID) processes, where deposited material does not move after impact with the evolving surface, and deposition efficiency remains constant. For a TID process, the CSP can be computed from the mass flux distribution using the Abel integral transform. The model is validated for cold spray (CS) and aerosol jet printing. Using the TID assumption enables the modeling of CS and AJP tracks from dot deposition data with height and width errors down to 11 and 22% for CS, and 7 and 21% for AJP. The error of this model when considering short and curved tracks is discussed, as well as the effects of nozzle standoff distance and tilt. Fast methods for arbitrary CSP computations and a fast CS method considering varying deposition efficiency are also discussed.
{"title":"Track cross-sectional profile model for time-invariant deposition processes — Applied to cold spray and aerosol jet printing","authors":"Alexander Martinez-Marchese , Alex-George Miclaus , Bahareh Marzbanrad , Ehsan Marzbanrad , Chen Qian , Max Wörner , Hamid Jahed , Ehsan Toyserkani , Chinedum Okwudire","doi":"10.1016/j.addlet.2025.100338","DOIUrl":"10.1016/j.addlet.2025.100338","url":null,"abstract":"<div><div>Modeling the track cross-sectional profile (CSP) in deposition processes is critical for assessing and controlling deposition quality. This article focuses on modeling time-invariant deposition (TID) processes, where deposited material does not move after impact with the evolving surface, and deposition efficiency remains constant. For a TID process, the CSP can be computed from the mass flux distribution using the Abel integral transform. The model is validated for cold spray (CS) and aerosol jet printing. Using the TID assumption enables the modeling of CS and AJP tracks from dot deposition data with height and width errors down to 11 and 22% for CS, and 7 and 21% for AJP. The error of this model when considering short and curved tracks is discussed, as well as the effects of nozzle standoff distance and tilt. Fast methods for arbitrary CSP computations and a fast CS method considering varying deposition efficiency are also discussed.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"15 ","pages":"Article 100338"},"PeriodicalIF":4.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145528329","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-07-01Epub Date: 2025-05-22DOI: 10.1016/j.addlet.2025.100293
Rion J. Wendland , Thomas J. Kolibaba , Kristan S. Worthington , Jason P. Killgore
The working curve is a widely implemented, but presently not standardized, method of assessing resin printability for photopolymer additive manufacturing technologies. While the working curve has been studied and refined for plastic resins, application to hydrogel materials used in bioprinting has been limited. Hydrogels present measurement challenges due to their decreased solids content, compliant nature, and significant swelling. Here, adapting lessons learned from interlaboratory studies on plastic working curves, we assess various techniques for hydrogel working curve measurements. Notably, across several formulations with various molecular weights and solids content, hydrogels exhibit near ideal log-linear behavior consistent with the Jacobs model when measured appropriately. However, certain measurement modalities (such as contact-based and rheological) can indicate Jacobs-like behavior, but with systematic errors in the cure depth compared to non-contact optical methods. Overall, this work highlights the challenges when conducting hydrogel working curve measurements and provides several considerations to help further develop and standardize measurements across 3D bioprinting applications.
{"title":"A practical guide to hydrogel working curves for bioprinting","authors":"Rion J. Wendland , Thomas J. Kolibaba , Kristan S. Worthington , Jason P. Killgore","doi":"10.1016/j.addlet.2025.100293","DOIUrl":"10.1016/j.addlet.2025.100293","url":null,"abstract":"<div><div>The working curve is a widely implemented, but presently not standardized, method of assessing resin printability for photopolymer additive manufacturing technologies. While the working curve has been studied and refined for plastic resins, application to hydrogel materials used in bioprinting has been limited. Hydrogels present measurement challenges due to their decreased solids content, compliant nature, and significant swelling. Here, adapting lessons learned from interlaboratory studies on plastic working curves, we assess various techniques for hydrogel working curve measurements. Notably, across several formulations with various molecular weights and solids content, hydrogels exhibit near ideal log-linear behavior consistent with the Jacobs model when measured appropriately. However, certain measurement modalities (such as contact-based and rheological) can indicate Jacobs-like behavior, but with systematic errors in the cure depth compared to non-contact optical methods. Overall, this work highlights the challenges when conducting hydrogel working curve measurements and provides several considerations to help further develop and standardize measurements across 3D bioprinting applications.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"14 ","pages":"Article 100293"},"PeriodicalIF":4.2,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144168482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-07-01Epub Date: 2025-06-23DOI: 10.1016/j.addlet.2025.100296
I. Liu , J. Hoarston , N. Zhu , A. Birt , N. Palya , B.J. Phillips , D.Z. Avery , P.G. Allison , J.B. Jordon
The need for long-lead time aluminum alloy casting and forging replacements requires innovative solutions such as Additive Friction Stir Deposition (AFSD), a solid-state additive manufacturing technique that uses frictional heat and severe plastic deformation to create metallurgical bonds through layer-by-layer deposition. While AFSD has demonstrated isotropic mechanical properties in the as-deposited condition, post-deposition heat treatment (PDHT) of precipitation hardened aluminum alloys processed by AFSD has led to poor ductility, particularly in the build direction. In this feasibility study, a lubricant-free twin rod AFSD (TR-AFSD) approach printed a 100 millimeter tall AA7050 build. Mechanical properties in the build direction were determined for a range of artificial aging times. Experimental results showed that a one hour aging time following a 24-hour solution treatment produced tensile yield, ultimate tensile strength, and strain to failure results of 360 ± 5.5 MPa, 463 ± 10.3 MPa, and 7.55 ± 2.00 %, respectively. Our feasibility study shows that forging-like tensile properties can be achieved in the build direction from TR-AFSD prints using a featureless tool coupled with a temperature control lubricant-free round feedstock approach and a custom PDHT schedule.
{"title":"Influence of aging time to achieve tensile build direction heat treated T74 forging properties in lubricant free AFSD AA7050","authors":"I. Liu , J. Hoarston , N. Zhu , A. Birt , N. Palya , B.J. Phillips , D.Z. Avery , P.G. Allison , J.B. Jordon","doi":"10.1016/j.addlet.2025.100296","DOIUrl":"10.1016/j.addlet.2025.100296","url":null,"abstract":"<div><div>The need for long-lead time aluminum alloy casting and forging replacements requires innovative solutions such as Additive Friction Stir Deposition (AFSD), a solid-state additive manufacturing technique that uses frictional heat and severe plastic deformation to create metallurgical bonds through layer-by-layer deposition. While AFSD has demonstrated isotropic mechanical properties in the as-deposited condition, post-deposition heat treatment (PDHT) of precipitation hardened aluminum alloys processed by AFSD has led to poor ductility, particularly in the build direction. In this feasibility study, a lubricant-free twin rod AFSD (TR-AFSD) approach printed a 100 millimeter tall AA7050 build. Mechanical properties in the build direction were determined for a range of artificial aging times. Experimental results showed that a one hour aging time following a 24-hour solution treatment produced tensile yield, ultimate tensile strength, and strain to failure results of 360 ± 5.5 MPa, 463 ± 10.3 MPa, and 7.55 ± 2.00 %, respectively. Our feasibility study shows that forging-like tensile properties can be achieved in the build direction from TR-AFSD prints using a featureless tool coupled with a temperature control lubricant-free round feedstock approach and a custom PDHT schedule.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"14 ","pages":"Article 100296"},"PeriodicalIF":4.2,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144535579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rotational Friction Welding (RFW) is a solid-state joining technique that enables the assembly of metallic components below their melting temperature, while also avoiding harmful gas emissions commonly associated with fusion-based methods. Despite their high mechanical strength, parts manufactured by RFW often struggle to meet the industrial demand for complex geometries beyond their typical cylindrical and disc shapes. Laser Powder Bed Fusion (PBF-LB/M) allows fabrication of geometrically intricate parts with high precision and mechanical reliability. However, it faces challenges such as high production costs and dimensional limitations. Combining PBF-LB/M with RFW enables the production of larger and complex metal parts. The purpose of this study is to demonstrate the feasibility and benefits of this hybrid approach for 316 L stainless steel (SS). To accomplish this, 316 L SS parts were initially fabricated using PBF-LB/M and then joined by RFW. The joints were analyzed to evaluate weld integrity, microstructural evolution, phase stability, and mechanical performance. The analysis reveals three distinct microstructural zones: the weld zone, the thermo-mechanically affected zone, and the base metal zone. Grain refinement is observed in the weld zone, whereas coarser grains appear toward the base metal zone. Phase analysis exhibits a fully austenitic structure without any detrimental secondary phases. Mechanical testing shows increased hardness in the weld zone associated with grain refinement. Tensile tests reveal that the fracture occurred outside the welding region, specifically in the base metal zone. These findings highlight a finer, defect-free weld zone without secondary phases in RFW joined PBF-LB/M 316 L SS components.
旋转摩擦焊（RFW）是一种固态连接技术，可以使金属部件的组装低于其熔化温度，同时也避免了通常与基于熔合的方法相关的有害气体排放。尽管RFW制造的零件具有很高的机械强度，但它们通常难以满足工业对复杂几何形状的需求，而不是典型的圆柱形和圆盘形状。激光粉末床融合（PBF-LB/M）可以制造几何复杂的零件，具有高精度和机械可靠性。然而，它面临着诸如高生产成本和尺寸限制等挑战。将PBF-LB/M与RFW相结合，可以生产更大、更复杂的金属零件。本研究的目的是证明这种混合方法对316l不锈钢（SS）的可行性和效益。为了实现这一目标，316 L SS零件最初使用PBF-LB/M制造，然后通过RFW连接。对接头进行了分析，以评估焊缝完整性、显微组织演变、相稳定性和力学性能。分析显示了三个不同的显微组织区：焊接区、热机械影响区和母材区。焊缝区晶粒细化，而母材区晶粒粗化。相分析显示其为完全的奥氏体结构，无任何有害的二次相。力学测试表明，随着晶粒细化，焊接区硬度增加。拉伸试验表明，断裂发生在焊接区之外，特别是在母材区。这些研究结果表明，在PBF-LB/ m316l SS组件的RFW中，没有二次相的焊缝区域更细、无缺陷。
{"title":"On joining additive manufactured metals via friction welding technology: a comprehensive mechanical and microstructural study on 316 L stainless steel components","authors":"Fatma Nur Depboylu , Loïc Jegou , Luciana Tavares , Andrei-Alexandru Popa","doi":"10.1016/j.addlet.2025.100309","DOIUrl":"10.1016/j.addlet.2025.100309","url":null,"abstract":"<div><div>Rotational Friction Welding (RFW) is a solid-state joining technique that enables the assembly of metallic components below their melting temperature, while also avoiding harmful gas emissions commonly associated with fusion-based methods. Despite their high mechanical strength, parts manufactured by RFW often struggle to meet the industrial demand for complex geometries beyond their typical cylindrical and disc shapes. Laser Powder Bed Fusion (PBF-LB/M) allows fabrication of geometrically intricate parts with high precision and mechanical reliability. However, it faces challenges such as high production costs and dimensional limitations. Combining PBF-LB/M with RFW enables the production of larger and complex metal parts. The purpose of this study is to demonstrate the feasibility and benefits of this hybrid approach for 316 L stainless steel (SS). To accomplish this, 316 L SS parts were initially fabricated using PBF-LB/M and then joined by RFW. The joints were analyzed to evaluate weld integrity, microstructural evolution, phase stability, and mechanical performance. The analysis reveals three distinct microstructural zones: the weld zone, the thermo-mechanically affected zone, and the base metal zone. Grain refinement is observed in the weld zone, whereas coarser grains appear toward the base metal zone. Phase analysis exhibits a fully austenitic structure without any detrimental secondary phases. Mechanical testing shows increased hardness in the weld zone associated with grain refinement. Tensile tests reveal that the fracture occurred outside the welding region, specifically in the base metal zone. These findings highlight a finer, defect-free weld zone without secondary phases in RFW joined PBF-LB/M 316 L SS components.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"14 ","pages":"Article 100309"},"PeriodicalIF":4.2,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144703767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-07-01Epub Date: 2025-06-20DOI: 10.1016/j.addlet.2025.100297
Farshad Malekpour , Marjan Abdali , Mehdi Hojjati , Krzysztof Skonieczny
Advances in sustainable resource utilization and innovative manufacturing techniques are driving efforts toward the prospect of human settlement on Mars, led by programs such as SpaceX’s Occupy Mars initiative. One promising approach involves the development of materials and processes that leverage in-situ Martian resources. In this study, we investigate the fabrication and characterization of a composite material consisting of Polyether-Ketone-Ketone (PEKK) incorporated with Martian Regolith Simulant (MRS), targeting sustainable applications in outer space. Amorphous PEKK was pulverized and mixed with sieved MRS particles, followed by extrusion through a twin-screw extruder to produce a filament with a consistent diameter suitable for Material Extrusion Additive Manufacturing (MEAM). A post-processing protocol, including annealing, was implemented to optimize the degree of crystallinity and improve mechanical properties. The filament quality and dispersion of regolith within the matrix were evaluated, and the composite was characterized through mechanical and thermomechanical analyses. Based on the material properties achieved, a conceptual Mars rover wheel featuring a lightweight graded structure was designed and successfully fabricated. These results demonstrate the early-stage feasibility of producing high-quality, mechanically robust 3D-printed components from regolith-based composites, highlighting the potential of integrating additive manufacturing with local resources as a step toward sustainable extraterrestrial exploration.
{"title":"Toward sustainable additive manufacturing of PEKK/Martian regolith composite for lightweight structural applications on Mars","authors":"Farshad Malekpour , Marjan Abdali , Mehdi Hojjati , Krzysztof Skonieczny","doi":"10.1016/j.addlet.2025.100297","DOIUrl":"10.1016/j.addlet.2025.100297","url":null,"abstract":"<div><div>Advances in sustainable resource utilization and innovative manufacturing techniques are driving efforts toward the prospect of human settlement on Mars, led by programs such as SpaceX’s Occupy Mars initiative. One promising approach involves the development of materials and processes that leverage in-situ Martian resources. In this study, we investigate the fabrication and characterization of a composite material consisting of Polyether-Ketone-Ketone (PEKK) incorporated with Martian Regolith Simulant (MRS), targeting sustainable applications in outer space. Amorphous PEKK was pulverized and mixed with sieved MRS particles, followed by extrusion through a twin-screw extruder to produce a filament with a consistent diameter suitable for Material Extrusion Additive Manufacturing (MEAM). A post-processing protocol, including annealing, was implemented to optimize the degree of crystallinity and improve mechanical properties. The filament quality and dispersion of regolith within the matrix were evaluated, and the composite was characterized through mechanical and thermomechanical analyses. Based on the material properties achieved, a conceptual Mars rover wheel featuring a lightweight graded structure was designed and successfully fabricated. These results demonstrate the early-stage feasibility of producing high-quality, mechanically robust 3D-printed components from regolith-based composites, highlighting the potential of integrating additive manufacturing with local resources as a step toward sustainable extraterrestrial exploration.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"14 ","pages":"Article 100297"},"PeriodicalIF":4.2,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144579815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-07-01Epub Date: 2025-07-20DOI: 10.1016/j.addlet.2025.100307
Jun Wang , Mark Taylor , Chenglei Diao , Ed Pickering , Jian Qin , Yao Lu , Sonia Martins Meco , Jialuo Ding , Stewart Williams
Hybrid wire-arc directed energy deposition (WDED), in which complex features are deposited onto a forged base, offers a cost-effective solution for manufacturing geometrically complex ultra-high-strength steel components, particularly for aerospace applications. However, cracking at the base forging/build interface during post-build heat treatment limits its widespread application. This study investigates the underlying causes of interfacial cracking, highlighting microstructural inhomogeneity, elemental segregation and transformation stresses as likely key contributing factors. A modified three-step post-build heat treatment incorporating a normalisation step was developed to mitigate some of these issues. The optimised process successfully suppressed cracking by refining prior-austenite grains before the application of a conventional quenching step. This enhanced tensile performance beyond AMS6419K standards, supporting the industrial implementation of hybrid WDED in aerospace structures.
{"title":"Insights into crack prevention and property improvement for additively manufactured ultra-high-strength steel structures with complex geometries","authors":"Jun Wang , Mark Taylor , Chenglei Diao , Ed Pickering , Jian Qin , Yao Lu , Sonia Martins Meco , Jialuo Ding , Stewart Williams","doi":"10.1016/j.addlet.2025.100307","DOIUrl":"10.1016/j.addlet.2025.100307","url":null,"abstract":"<div><div>Hybrid wire-arc directed energy deposition (WDED), in which complex features are deposited onto a forged base, offers a cost-effective solution for manufacturing geometrically complex ultra-high-strength steel components, particularly for aerospace applications. However, cracking at the base forging/build interface during post-build heat treatment limits its widespread application. This study investigates the underlying causes of interfacial cracking, highlighting microstructural inhomogeneity, elemental segregation and transformation stresses as likely key contributing factors. A modified three-step post-build heat treatment incorporating a normalisation step was developed to mitigate some of these issues. The optimised process successfully suppressed cracking by refining prior-austenite grains before the application of a conventional quenching step. This enhanced tensile performance beyond AMS6419K standards, supporting the industrial implementation of hybrid WDED in aerospace structures.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"14 ","pages":"Article 100307"},"PeriodicalIF":4.2,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144686272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-07-01Epub Date: 2025-07-24DOI: 10.1016/j.addlet.2025.100305
M. Delcroix, G. Roy, C. van der Rest, V. Marchal-Marchant, P.J. Jacques
In the present study, the n-type Fe VAl0.9 Si0.1 was printed by laser powder bed fusion (L-PBF) for the first time. This work highlights the complexity of processing non-metallic materials by L-PBF and the need for advanced optimization strategies. A Single Scan Tracks (SSTs) analysis was conducted as usually done for materials newly processed by L-PBF as well as a top-down approach based on printing parameters of stainless steel. Process parameter sets based on SST analysis led to overheating while the stainless-steel-based strategy successfully produced bulk samples. Printed samples transitioned rapidly from cold defects (i.e. lack-of-fusion) to overheating as the printing parameters were varied. Moreover, high density samples were printed with parameters that would produce insufficient melting in the case of SSTs. Successive parallel tracks were printed and revealed a transition from unmelting to balling to continuous densification, demonstrating the critical role of heat accumulation. The microstructure of printed samples was analyzed, and their thermoelectric properties were measured. Transverse cold cracks, perpendicular to the scanning direction were observed. Statistical analysis on SST demonstrated that these cracks were insensitive to laser parameter variations, significantly decreasing the thermoelectric performance of bulk samples.
{"title":"Processing of Thermoelectric Fe2VAl Heusler-compounds by laser powder bed fusion: From single scan tracks to bulk material","authors":"M. Delcroix, G. Roy, C. van der Rest, V. Marchal-Marchant, P.J. Jacques","doi":"10.1016/j.addlet.2025.100305","DOIUrl":"10.1016/j.addlet.2025.100305","url":null,"abstract":"<div><div>In the present study, the n-type Fe<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> VAl<sub>0.9</sub> Si<sub>0.1</sub> was printed by laser powder bed fusion (L-PBF) for the first time. This work highlights the complexity of processing non-metallic materials by L-PBF and the need for advanced optimization strategies. A Single Scan Tracks (SSTs) analysis was conducted as usually done for materials newly processed by L-PBF as well as a top-down approach based on printing parameters of stainless steel. Process parameter sets based on SST analysis led to overheating while the stainless-steel-based strategy successfully produced bulk samples. Printed samples transitioned rapidly from cold defects (i.e. lack-of-fusion) to overheating as the printing parameters were varied. Moreover, high density samples were printed with parameters that would produce insufficient melting in the case of SSTs. Successive parallel tracks were printed and revealed a transition from unmelting to balling to continuous densification, demonstrating the critical role of heat accumulation. The microstructure of printed samples was analyzed, and their thermoelectric properties were measured. Transverse cold cracks, perpendicular to the scanning direction were observed. Statistical analysis on SST demonstrated that these cracks were insensitive to laser parameter variations, significantly decreasing the thermoelectric performance of bulk samples.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"14 ","pages":"Article 100305"},"PeriodicalIF":4.7,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144766968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-07-01Epub Date: 2025-05-03DOI: 10.1016/j.addlet.2025.100287
Philip König, Sebastian Weber, Jonathan Lentz
This study introduces martensitic Cr steels into additive manufacturing (AM) and provides first important findings for its PBF-LB/M processing. The comprehensive approach covers the entire process chain, including alloy modification, powder production, additive manufacturing, and microstructural characterization. Nitrogen (N), as an interstitial element soluble in iron, plays a central role in this strategy, offering economic and sustainability benefits during powder production while improving the PBF-LB/M-processability and performance of the final components. The atomizing gas N₂ was employed in vacuum induction gas atomization (VIGA) to facilitate direct alloying with N in the powder production process. A thermodynamic calculation-based alloying adjustment of the base alloy resulted in an increased N concentration of approximately 0.17 mass% in the powder. Consequently, electron backscatter diffraction (EBSD) and X-ray diffraction (XRD) studies demonstrate a notable increase in austenite content in the PBF-LB/M state. This finding aligns with thermodynamic predictions regarding the impact of N on austenite stability, reducing the propensity for cold cracking.
本研究将马氏体Cr钢引入增材制造（AM），并为其PBF-LB/M工艺提供了第一个重要发现。全面的方法涵盖了整个工艺链，包括合金改性，粉末生产，增材制造和微观结构表征。氮(N)作为一种可溶于铁的间隙元素，在这一策略中发挥着核心作用，在粉末生产过程中提供经济和可持续效益，同时提高PBF-LB/ m -最终组分的可加工性和性能。采用雾化气体n2进行真空感应气体雾化（VIGA），便于粉末生产过程中与N直接合金化。基于热力学计算的基体合金合金化调整导致粉末中N浓度增加约0.17质量%。因此，电子背散射衍射（EBSD）和x射线衍射（XRD）研究表明，在PBF-LB/M状态下，奥氏体含量显著增加。这一发现与热力学预测一致，即N对奥氏体稳定性的影响，减少了冷裂的倾向。
{"title":"Introduction of Cr steels to additive manufacturing using an innovative alloying approach - Challenges and Potentials","authors":"Philip König, Sebastian Weber, Jonathan Lentz","doi":"10.1016/j.addlet.2025.100287","DOIUrl":"10.1016/j.addlet.2025.100287","url":null,"abstract":"<div><div>This study introduces martensitic Cr steels into additive manufacturing (AM) and provides first important findings for its PBF-LB/M processing. The comprehensive approach covers the entire process chain, including alloy modification, powder production, additive manufacturing, and microstructural characterization. Nitrogen (N), as an interstitial element soluble in iron, plays a central role in this strategy, offering economic and sustainability benefits during powder production while improving the PBF-LB/M-processability and performance of the final components. The atomizing gas N₂ was employed in vacuum induction gas atomization (VIGA) to facilitate direct alloying with N in the powder production process. A thermodynamic calculation-based alloying adjustment of the base alloy resulted in an increased N concentration of approximately 0.17 mass% in the powder. Consequently, electron backscatter diffraction (EBSD) and X-ray diffraction (XRD) studies demonstrate a notable increase in austenite content in the PBF-LB/M state. This finding aligns with thermodynamic predictions regarding the impact of N on austenite stability, reducing the propensity for cold cracking.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"14 ","pages":"Article 100287"},"PeriodicalIF":4.2,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143912556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-07-01Epub Date: 2025-06-11DOI: 10.1016/j.addlet.2025.100292
Peter Pak , Amir Barati Farimani
In this work we investigate the ability of large language models to predict additive manufacturing defect regimes given a set of process parameter inputs. For this task we utilize a process parameter defect dataset to fine-tune a collection of models, titled AdditiveLLM, for the purpose of predicting potential defect regimes including Keyholing, Lack of Fusion, and Balling. We compare different methods of input formatting in order to gauge the model’s performance to correctly predict defect regimes on our sparse Baseline dataset and our natural language Prompt dataset. The model displays robust predictive capability, achieving a Baseline accuracy of 94% and Prompt accuracy of 82% when asked to provide the defect regimes associated with a set of process parameters. The incorporation of natural language input further simplifies the task of process parameters selection, enabling users to identify optimal settings specific to their build.
在这项工作中，我们研究了给定一组工艺参数输入的大型语言模型预测增材制造缺陷制度的能力。对于这个任务，我们利用一个过程参数缺陷数据集来微调一组模型，标题为AdditiveLLM，用于预测潜在的缺陷机制，包括Keyholing、Lack of Fusion和Balling。我们比较了不同的输入格式方法，以衡量模型在稀疏基线数据集和自然语言提示数据集上正确预测缺陷制度的性能。该模型显示出强大的预测能力，当要求提供与一组过程参数相关的缺陷制度时，达到94%的基线准确度和82%的提示准确度。自然语言输入的结合进一步简化了过程参数选择的任务，使用户能够确定特定于其构建的最佳设置。
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Pub Date : 2025-07-01Epub Date: 2025-05-09DOI: 10.1016/j.addlet.2025.100289
A. ElSherbiny, A.J. Qureshi, P. Mertiny
Additive manufacturing (AM) has revolutionized modern manufacturing by enabling the rapid prototyping and production of complex geometries with minimal material waste. Among AM techniques, Fused Filament Fabrication (FFF) is widely used for polymer-based manufacturing but exhibits limitations in high-performance applications due to insufficient mechanical properties. To address these shortcomings, this study focuses on advancing a standard FFF system to integrate Continuous Carbon Fiber (CCF) and implement interweaving deposition patterns, with the goal of enhancing structural performance and integrity. Representative volume element modeling and finite element analysis were conducted to evaluate the mechanical behavior, with results validated through experimental mechanical testing. The results confirm that CCF reinforcement improves the mechanical performance of printed components, particularly in the raster direction, although variations in response highlight the influence of material imperfections and non-linearities. The study demonstrates the potential of advanced CCF 3D printing in addressing the limitations of traditional FFF and provides insights for further advancements in polymer composite AM.
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