Pub Date : 2026-02-01Epub Date: 2025-12-05DOI: 10.1016/j.addlet.2025.100348
Filip Seidler, Jakub Slavíček, Daniel Koutný
This study investigates the impact of various deposition strategies on the microstructure of volumetric components fabricated from AZ61 magnesium alloy using Wire Arc Direct Energy Deposition (WADED), also referred to as Wire Arc Additive Manufacturing (WAAM). Because coarse grains can significantly reduce mechanical performance, thermal simulations were performed to identify low-cooling-rate regions associated with different deposition trajectories. Three deposition strategies were analysed: ZigZag, Spiral, and S-pattern. The simulated thermal profiles were validated by optical grain size analysis and hardness measurements. In the selected critical regions, where the largest grains are expected, the S-pattern achieved the narrowest range in grain size and hardness distribution. This trajectory also exhibited the finest microstructure in most critical region, with the smallest average grain size. Additionally, it maintained good geometrical accuracy, indicating that it offers a promising route for producing high-quality magnesium-alloy components via WADED.
{"title":"Influence of deposition strategy on the microstructure of volumetric WADED-fabricated AZ61 magnesium alloy components","authors":"Filip Seidler, Jakub Slavíček, Daniel Koutný","doi":"10.1016/j.addlet.2025.100348","DOIUrl":"10.1016/j.addlet.2025.100348","url":null,"abstract":"<div><div>This study investigates the impact of various deposition strategies on the microstructure of volumetric components fabricated from AZ61 magnesium alloy using Wire Arc Direct Energy Deposition (WADED), also referred to as Wire Arc Additive Manufacturing (WAAM). Because coarse grains can significantly reduce mechanical performance, thermal simulations were performed to identify low-cooling-rate regions associated with different deposition trajectories. Three deposition strategies were analysed: ZigZag, Spiral, and S-pattern. The simulated thermal profiles were validated by optical grain size analysis and hardness measurements. In the selected critical regions, where the largest grains are expected, the S-pattern achieved the narrowest range in grain size and hardness distribution. This trajectory also exhibited the finest microstructure in most critical region, with the smallest average grain size. Additionally, it maintained good geometrical accuracy, indicating that it offers a promising route for producing high-quality magnesium-alloy components via WADED.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"16 ","pages":"Article 100348"},"PeriodicalIF":4.7,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145712242","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 : 2026-02-01Epub Date: 2025-12-30DOI: 10.1016/j.addlet.2025.100352
Marco Zago , Thomas Grippi , Elisa Torresani , Matteo Perina , Eugene A. Olevsky , Ilaria Cristofolini
This study investigates the origin of distortion during sintering of 316 L stainless steel components produced by binder jetting, focusing on friction between the sample and the support surface and on density inhomogeneity in the green state. A design of experiments (DoE) approach evaluates the influence of key printing parameters on the sintering behavior of two geometries with different through-hole sizes. Dimensional measurements, and density profiling, are performed in both green and sintered states. Sintering simulations use the Skorokhod-Olevsky viscous sintering (SOVS) model and include experimentally measured density gradients and frictional effects.
Results show that green density varies significantly (52% to 58%) depending on printing parameters, especially binder saturation, and exhibits directional dependence. These variations lead to measurable distortions during sintering. Simulations that include both friction and density gradients match experimental deformations with deviations below 4%. A compensation strategy that places parts on co-sintered 316 L support plates with interposed refractory particles reduces distortion to <1.5%.
This work demonstrates the combined role of friction and density gradients in sintering distortion and presents a practical method to improve dimensional accuracy in binder jetting.
{"title":"Friction-induced distortion in binder jetted 316 L stainless steel: Experimental analysis, simulation, and compensation strategy","authors":"Marco Zago , Thomas Grippi , Elisa Torresani , Matteo Perina , Eugene A. Olevsky , Ilaria Cristofolini","doi":"10.1016/j.addlet.2025.100352","DOIUrl":"10.1016/j.addlet.2025.100352","url":null,"abstract":"<div><div>This study investigates the origin of distortion during sintering of 316 L stainless steel components produced by binder jetting, focusing on friction between the sample and the support surface and on density inhomogeneity in the green state. A design of experiments (DoE) approach evaluates the influence of key printing parameters on the sintering behavior of two geometries with different through-hole sizes. Dimensional measurements, and density profiling, are performed in both green and sintered states. Sintering simulations use the Skorokhod-Olevsky viscous sintering (SOVS) model and include experimentally measured density gradients and frictional effects.</div><div>Results show that green density varies significantly (52% to 58%) depending on printing parameters, especially binder saturation, and exhibits directional dependence. These variations lead to measurable distortions during sintering. Simulations that include both friction and density gradients match experimental deformations with deviations below 4%. A compensation strategy that places parts on co-sintered 316 L support plates with interposed refractory particles reduces distortion to <1.5%.</div><div>This work demonstrates the combined role of friction and density gradients in sintering distortion and presents a practical method to improve dimensional accuracy in binder jetting.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"16 ","pages":"Article 100352"},"PeriodicalIF":4.7,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145939218","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}
This paper discusses a P91 steel block that was additively manufactured by wire arc direct energy deposition (WA-DED) followed by two types of post-process heat treatment (PPHT). Vickers microhardness and digital image correlation tensile tests were performed along the building direction. The global mechanical properties (i.e., microhardness and tensile properties) and the local mechanical responses (i.e., hardness fluctuation and strain localization) were systematically investigated. Results showed that (1) all P91 specimens showed higher strengths than American Society of Mechanical Engineers standard requirements for wrought P91 steel, (2) the as-printed P91 exhibited much higher average hardness and fluctuations than that after PPHT, (3) PPHT reduced P91 strengths but improved the ductility significantly, and (4) strain localization presented in the as-printed specimen during uniform deformation in tensile tests. The hardness fluctuation and strain localization along the building direction of the AP P91 were caused by different thermal histories received during WA-DED. The study indicated that PPHT, ideally tempering-only heat treatment, is necessary for the WA-DED printed P91 steel.
{"title":"Mechanical properties and strain localization of WA-DED printed P91 steel","authors":"Wei Tang , Saket Thapliyal , Yukinori Yamamoto , Andrzej Nycz , Riley Wallace , Peeyush Nandwana","doi":"10.1016/j.addlet.2025.100351","DOIUrl":"10.1016/j.addlet.2025.100351","url":null,"abstract":"<div><div>This paper discusses a P91 steel block that was additively manufactured by wire arc direct energy deposition (WA-DED) followed by two types of post-process heat treatment (PPHT). Vickers microhardness and digital image correlation tensile tests were performed along the building direction. The global mechanical properties (i.e., microhardness and tensile properties) and the local mechanical responses (i.e., hardness fluctuation and strain localization) were systematically investigated. Results showed that (1) all P91 specimens showed higher strengths than American Society of Mechanical Engineers standard requirements for wrought P91 steel, (2) the as-printed P91 exhibited much higher average hardness and fluctuations than that after PPHT, (3) PPHT reduced P91 strengths but improved the ductility significantly, and (4) strain localization presented in the as-printed specimen during uniform deformation in tensile tests. The hardness fluctuation and strain localization along the building direction of the AP P91 were caused by different thermal histories received during WA-DED. The study indicated that PPHT, ideally tempering-only heat treatment, is necessary for the WA-DED printed P91 steel.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"16 ","pages":"Article 100351"},"PeriodicalIF":4.7,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145939217","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 : 2026-02-01Epub Date: 2025-11-25DOI: 10.1016/j.addlet.2025.100344
Henry D. Davis , James G. Harkness , David K. Hayes , Brian D. Jensen , Richard Vanfleet , Nathan B. Crane , Robert C. Davis
Interfacing is a consistent weak point in the manufacturing of microscale gas chromatography columns. Current techniques for interfacing with microfluidic systems often degrade under high temperatures and thermal cycling and suffer from dead volumes. To address these challenges, we fabricated all-metal interfaces that connect 3D-printed microchannels (500 µm diameter) to industry-standard stainless-steel (SS) capillaries. Our fabrication process uses SS binder-jet printing and bronze infiltration to fuse the capillary to the printed part and reduce dead volumes at the interface while utilizing pressure control to prevent the infiltrant from filling the channel or capillary. These interfaces withstood pressures greater than 100 PSI and showed no leakage after thermal cycling to 350 °C. Cross-sections of the interfaces show smooth connections between the channel and capillary with minimal dead volume.
{"title":"Binder-jet printing and pressure-controlled infiltration for fabrication of high-temperature, low-dead-volume microfluidic interfaces","authors":"Henry D. Davis , James G. Harkness , David K. Hayes , Brian D. Jensen , Richard Vanfleet , Nathan B. Crane , Robert C. Davis","doi":"10.1016/j.addlet.2025.100344","DOIUrl":"10.1016/j.addlet.2025.100344","url":null,"abstract":"<div><div>Interfacing is a consistent weak point in the manufacturing of microscale gas chromatography columns. Current techniques for interfacing with microfluidic systems often degrade under high temperatures and thermal cycling and suffer from dead volumes. To address these challenges, we fabricated all-metal interfaces that connect 3D-printed microchannels (500 µm diameter) to industry-standard stainless-steel (SS) capillaries. Our fabrication process uses SS binder-jet printing and bronze infiltration to fuse the capillary to the printed part and reduce dead volumes at the interface while utilizing pressure control to prevent the infiltrant from filling the channel or capillary. These interfaces withstood pressures greater than 100 PSI and showed no leakage after thermal cycling to 350 °C. Cross-sections of the interfaces show smooth connections between the channel and capillary with minimal dead volume.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"16 ","pages":"Article 100344"},"PeriodicalIF":4.7,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145712243","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 : 2025-12-01Epub Date: 2025-10-04DOI: 10.1016/j.addlet.2025.100330
Robert C. Pack , John W. Bohling , Joshua Kincaid , Abrian Abir , Tony Schmitz , Brett G. Compton
Aluminum metal matrix composites (MMCs) possess good strength and stiffness combined with low density, making them attractive in a variety of applications. Additive friction stir deposition (AFSD) is a relatively new, solid state metal additive manufacturing process that has high potential as a forming route for MMCs of complex shape. However, little work has been done to investigate how AFSD affects microstructure and properties of conventional MMCs. In this work, aluminum-silicon carbide (Al-SiC) MMC extruded plate was used as feedstock for AFSD to create a five-layer deposit of an Al-SiC MMC for characterization. Microstructure, particle size distribution, and hardness were evaluated in the as-deposited condition while hardness recovery was investigated with post-deposition solution and aging heat treatments. The deposited MMC revealed complex, macroscale mixing behavior, mild fragmentation of the SiC particles, and uniform particle size distribution and dispersion across MMC regions of the deposit. Solution and aging heat treatment restored the hardness of the deposited MMC to that of the as-received feedstock. This work suggests AFSD is a promising route for producing complex MMC parts with similar or better properties to those produced by traditional processes.
{"title":"Additive friction stir deposition of multi-layer aluminum-silicon carbide metal matrix composites","authors":"Robert C. Pack , John W. Bohling , Joshua Kincaid , Abrian Abir , Tony Schmitz , Brett G. Compton","doi":"10.1016/j.addlet.2025.100330","DOIUrl":"10.1016/j.addlet.2025.100330","url":null,"abstract":"<div><div>Aluminum metal matrix composites (MMCs) possess good strength and stiffness combined with low density, making them attractive in a variety of applications. Additive friction stir deposition (AFSD) is a relatively new, solid state metal additive manufacturing process that has high potential as a forming route for MMCs of complex shape. However, little work has been done to investigate how AFSD affects microstructure and properties of conventional MMCs. In this work, aluminum-silicon carbide (Al-SiC) MMC extruded plate was used as feedstock for AFSD to create a five-layer deposit of an Al-SiC MMC for characterization. Microstructure, particle size distribution, and hardness were evaluated in the as-deposited condition while hardness recovery was investigated with post-deposition solution and aging heat treatments. The deposited MMC revealed complex, macroscale mixing behavior, mild fragmentation of the SiC particles, and uniform particle size distribution and dispersion across MMC regions of the deposit. Solution and aging heat treatment restored the hardness of the deposited MMC to that of the as-received feedstock. This work suggests AFSD is a promising route for producing complex MMC parts with similar or better properties to those produced by traditional processes.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"15 ","pages":"Article 100330"},"PeriodicalIF":4.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145267139","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 : 2025-12-01Epub Date: 2025-09-17DOI: 10.1016/j.addlet.2025.100324
P. Markovic , P. Scheel , R. Wróbel , S. Van Petegem , C. Leinenbach , E. Mazza , E. Hosseini
Laser Powder Bed Fusion (LPBF) is a widely adopted metal additive manufacturing technology that enables the fabrication of intricate metal components, yet it faces challenges arising from intrinsic residual stress and distortion development. High-fidelity thermomechanical simulations offer essential insights for predicting and mitigating these effects. The reliability of such simulations depends on various factors, but critically on the material input data, primarily the constitutive model which should accurately represent the material’s deformation behaviour under the complex loading conditions expected during LPBF. The present study integrates an advanced elastic-viscoplastic constitutive model into the LPBF thermomechanical simulation, capable of capturing the cyclic response of LPBF Hastelloy X across a broad range of temperatures and strain rates, and accounting for both isotropic and kinematic hardening. Simulation outcomes are validated against in-situ temperature and distortion measurements obtained during an LPBF experiment for Hastelloy X. Acknowledging the extensive effort required to develop such an advanced constitutive model, this study also calibrates three alternative models of simpler formulation to assess the impact of model selection on simulation outcomes and computational cost. The four investigated models span from rate-dependent elastic-viscoplastic to rate-independent elastic-plastic formulations, each with different capabilities for representing the alloy’s cyclic hardening response. The results provide valuable insights into trade-offs between simulation accuracy, constitutive model development effort, and computational efficiency in LPBF thermomechanical simulations.
{"title":"High-fidelity thermomechanical simulation of laser powder bed fusion process: Impact of constitutive model choice","authors":"P. Markovic , P. Scheel , R. Wróbel , S. Van Petegem , C. Leinenbach , E. Mazza , E. Hosseini","doi":"10.1016/j.addlet.2025.100324","DOIUrl":"10.1016/j.addlet.2025.100324","url":null,"abstract":"<div><div>Laser Powder Bed Fusion (LPBF) is a widely adopted metal additive manufacturing technology that enables the fabrication of intricate metal components, yet it faces challenges arising from intrinsic residual stress and distortion development. High-fidelity thermomechanical simulations offer essential insights for predicting and mitigating these effects. The reliability of such simulations depends on various factors, but critically on the material input data, primarily the constitutive model which should accurately represent the material’s deformation behaviour under the complex loading conditions expected during LPBF. The present study integrates an advanced elastic-viscoplastic constitutive model into the LPBF thermomechanical simulation, capable of capturing the cyclic response of LPBF Hastelloy X across a broad range of temperatures and strain rates, and accounting for both isotropic and kinematic hardening. Simulation outcomes are validated against in-situ temperature and distortion measurements obtained during an LPBF experiment for Hastelloy X. Acknowledging the extensive effort required to develop such an advanced constitutive model, this study also calibrates three alternative models of simpler formulation to assess the impact of model selection on simulation outcomes and computational cost. The four investigated models span from rate-dependent elastic-viscoplastic to rate-independent elastic-plastic formulations, each with different capabilities for representing the alloy’s cyclic hardening response. The results provide valuable insights into trade-offs between simulation accuracy, constitutive model development effort, and computational efficiency in LPBF thermomechanical simulations.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"15 ","pages":"Article 100324"},"PeriodicalIF":4.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145105126","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 : 2025-12-01Epub Date: 2025-09-08DOI: 10.1016/j.addlet.2025.100321
Fanshuo Wang , Qiyang Tan , Ting Liu , Jeffrey Venezuela , Zhiming Shi , Sarah Hurley , Anh Ly , Chun Xu , Deniz U. Erbulurt , Jun Yin , Yue Zhao , Mingxing Zhang
This study investigates the biodegradation of pure Fe, Fe-25Mn, and Fe-30Mn alloys fabricated with laser powder bed fusion (LPBF). Unlike conventionally produced Fe-Mn alloys, in the scheme of LPBF, the addition of 25 wt.% and 30 wt.% Mn showed limited efficacy in enhancing the corrosion rates when compared with the LPBF-fabricated Fe. The rapid cooling during LPBF produced a refined grain structure in pure Fe, substantially increased the grain boundary density, and enhanced the corrosion rates. This effect resulted in a corrosion rate of LPBF-processed Fe (0.04mm/year) that matched the corrosion rate of the LPBF-fabricated Fe-25Mn (0.05mm/year) with enhanced galvanic corrosion due to a high ε-martensite to γ-austenite ratio. Whereas in the LPBF-fabricated Fe-30Mn alloy, a reduced corrosion rate (0.01mm/year) was determined because of its coarse columnar grains and constrained micro-galvanic effects derived from the low ε-martensite to γ-austenite ratio. These findings suggest that when LPBF is used to produce biodegradable Fe-based alloys, Fe could be a more optimal option than its Fe- (25 and 30 wt.%) Mn counterparts in terms of pursuing a faster degradation rate.
{"title":"Reassessing the biodegradation behavior of pure iron and iron-manganese alloys fabricated by laser powder bed fusion","authors":"Fanshuo Wang , Qiyang Tan , Ting Liu , Jeffrey Venezuela , Zhiming Shi , Sarah Hurley , Anh Ly , Chun Xu , Deniz U. Erbulurt , Jun Yin , Yue Zhao , Mingxing Zhang","doi":"10.1016/j.addlet.2025.100321","DOIUrl":"10.1016/j.addlet.2025.100321","url":null,"abstract":"<div><div>This study investigates the biodegradation of pure Fe, Fe-25Mn, and Fe-30Mn alloys fabricated with laser powder bed fusion (LPBF). Unlike conventionally produced Fe-Mn alloys, in the scheme of LPBF, the addition of 25 wt.% and 30 wt.% Mn showed limited efficacy in enhancing the corrosion rates when compared with the LPBF-fabricated Fe. The rapid cooling during LPBF produced a refined grain structure in pure Fe, substantially increased the grain boundary density, and enhanced the corrosion rates. This effect resulted in a corrosion rate of LPBF-processed Fe (0.04mm/year) that matched the corrosion rate of the LPBF-fabricated Fe-25Mn (0.05mm/year) with enhanced galvanic corrosion due to a high ε-martensite to γ-austenite ratio. Whereas in the LPBF-fabricated Fe-30Mn alloy, a reduced corrosion rate (0.01mm/year) was determined because of its coarse columnar grains and constrained micro-galvanic effects derived from the low ε-martensite to γ-austenite ratio. These findings suggest that when LPBF is used to produce biodegradable Fe-based alloys, Fe could be a more optimal option than its Fe- (25 and 30 wt.%) Mn counterparts in terms of pursuing a faster degradation rate.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"15 ","pages":"Article 100321"},"PeriodicalIF":4.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145049657","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 : 2025-12-01Epub Date: 2025-08-28DOI: 10.1016/j.addlet.2025.100320
Shaharyar Baig , Alireza Jam , Stefano Beretta , Shuai Shao , Nima Shamsaei
This study evaluated the effectiveness of x-ray computed tomography (XCT) based examinations in assessing the fatigue lives of laser powder bed fused (L-PBF) aluminum alloys. L-PBF AlSi10Mg and Scalmalloy specimens with varying defect populations were examined via XCT prior to uniaxial fatigue testing. By correlating the post-fracture surface information with XCT data, the fatigue critical defects were identified and quantified; and the efficacy of XCT in accurately capturing these defects and measuring their sizes was assessed. The results indicated that lack-of-fusions (LoFs) with thin webbed features were prone to significant loss of information in XCT scans compared to bulky shaped defects, leading to frequent misidentification of critical defects and/or misrepresentation of their actual size. Accordingly, fatigue modelling relying solely on the largest detected entities in XCT scans of L-PBF aluminum alloys, which contained large critical LoFs, resulted in severely non-conservative fatigue life predictions. It was demonstrated that a distance-based criterion can help address the limitations in XCT data by allowing for the defect morphology to be reconstructed, which gave rise to improved size estimates, and in many cases, the correct identification of the critical defect. Incorporating corrected XCT data into crack growth based models enabled accurate and moderately conservative fatigue life estimates for non-destructive structural integrity assessments.
{"title":"Fatigue assessment of laser powder bed fused aluminum alloys via non-destructive examination","authors":"Shaharyar Baig , Alireza Jam , Stefano Beretta , Shuai Shao , Nima Shamsaei","doi":"10.1016/j.addlet.2025.100320","DOIUrl":"10.1016/j.addlet.2025.100320","url":null,"abstract":"<div><div>This study evaluated the effectiveness of x-ray computed tomography (XCT) based examinations in assessing the fatigue lives of laser powder bed fused (L-PBF) aluminum alloys. L-PBF AlSi10Mg and Scalmalloy specimens with varying defect populations were examined via XCT prior to uniaxial fatigue testing. By correlating the post-fracture surface information with XCT data, the fatigue critical defects were identified and quantified; and the efficacy of XCT in accurately capturing these defects and measuring their sizes was assessed. The results indicated that lack-of-fusions (LoFs) with thin webbed features were prone to significant loss of information in XCT scans compared to bulky shaped defects, leading to frequent misidentification of critical defects and/or misrepresentation of their actual size. Accordingly, fatigue modelling relying solely on the largest detected entities in XCT scans of L-PBF aluminum alloys, which contained large critical LoFs, resulted in severely non-conservative fatigue life predictions. It was demonstrated that a distance-based criterion can help address the limitations in XCT data by allowing for the defect morphology to be reconstructed, which gave rise to improved size estimates, and in many cases, the correct identification of the critical defect. Incorporating corrected XCT data into crack growth based models enabled accurate and moderately conservative fatigue life estimates for non-destructive structural integrity assessments.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"15 ","pages":"Article 100320"},"PeriodicalIF":4.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144917775","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 : 2025-12-01Epub Date: 2025-09-11DOI: 10.1016/j.addlet.2025.100323
Hamid Aghajani, Ehsan Toyserkani
In the present study, CM247LC, a non-weldable Ni-base superalloy, was fabricated by electron beam powder bed fusion (EB-PBF) over a wide energy levels. For this purpose, variable process parameters were adjusted to investigate their effect on microstructure and crack formation. Samples fabricated at both low and high area energies exhibited pronounced crack susceptibility. At very low energy densities, lack of fusion (LoF) and porosities were observed, while higher energy densities produced denser samples. Adjustments to energy density and process parameters resulted in a grain structure transition from fine-columnar to coarse-columnar and near-single crystal morphologies. Despite these changes, the cracking issue persisted, with micro-cracks observed in low-energy samples and macro-scale cracks, several millimeters long, forming at higher energy densities, highlighting the material’s high sensitivity to crack formation. Both solidification and liquation cracking were identified— the former showing dendritic crack surfaces, and the latter associated with eutectic phases and grain boundary precipitates. Severe recrystallization around cracks was observed at high energy densities, characterized by elevated dislocation densities. EDS analysis revealed hafnium- and silicon-rich precipitates in interdendritic regions and near cracks, contributing to severe hot cracking in the material.
{"title":"From micro- to macro-cracks and recrystallization in a non-weldable Ni-based superalloy manufactured by electron beam powder bed fusion","authors":"Hamid Aghajani, Ehsan Toyserkani","doi":"10.1016/j.addlet.2025.100323","DOIUrl":"10.1016/j.addlet.2025.100323","url":null,"abstract":"<div><div>In the present study, CM247LC, a non-weldable Ni-base superalloy, was fabricated by electron beam powder bed fusion (EB-PBF) over a wide energy levels. For this purpose, variable process parameters were adjusted to investigate their effect on microstructure and crack formation. Samples fabricated at both low and high area energies exhibited pronounced crack susceptibility. At very low energy densities, lack of fusion (LoF) and porosities were observed, while higher energy densities produced denser samples. Adjustments to energy density and process parameters resulted in a grain structure transition from fine-columnar to coarse-columnar and near-single crystal morphologies. Despite these changes, the cracking issue persisted, with micro-cracks observed in low-energy samples and macro-scale cracks, several millimeters long, forming at higher energy densities, highlighting the material’s high sensitivity to crack formation. Both solidification and liquation cracking were identified— the former showing dendritic crack surfaces, and the latter associated with eutectic phases and grain boundary precipitates. Severe recrystallization around cracks was observed at high energy densities, characterized by elevated dislocation densities. EDS analysis revealed hafnium- and silicon-rich precipitates in interdendritic regions and near cracks, contributing to severe hot cracking in the material.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"15 ","pages":"Article 100323"},"PeriodicalIF":4.7,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145049658","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 : 2025-12-01Epub Date: 2025-10-14DOI: 10.1016/j.addlet.2025.100334
Leonhard Hambitzer , Richard Prediger , Yaxuan Sun , Joseph Toombs , Zahra Hosneolfat , Ramin Montazeri , Sebastian Kluck , Hayden K. Taylor , Frederik Kotz-Helmer
Computed axial lithography is a volumetric additive manufacturing technique offering layer-free structuring and high fabrication speed by projecting a dynamic light pattern into a volume of photocurable resin. Ceramic and glass processing could benefit from this technology, as many applications, such as optics or bone grafts, require 3D structuring. However, developing suitable resins is challenging as high transparency of the photocurable resins is a necessity and standard particle-based resins are typically not transparent. In this study, we explored three novel approaches to fabricate transparent resins for structuring multioxide glasses and ceramics using computed axial lithography. The resins were composed of an acrylate-based binder and contained either nanoparticles, nanoparticles with an organic–inorganic precursor or only organic–inorganic precursors, as the glass or ceramic sources. The prints were thermally converted into pure glass or ceramic. We demonstrated this process for bioactive glass, bioactive calcium phosphate ceramic, and transparent titanium dioxide-doped silica glass. Microscaffolds were fabricated, and each material system was characterized regarding its suitability for computed axial lithography. This work expands the range of available computed axial lithography materials for microstructuring of functional multioxide glasses and ceramics.
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