Pub Date : 2025-10-04DOI: 10.1016/j.addlet.2025.100328
Leo Körber , Thomas Wettemann , Margarita Etchegaray Bello , Isabell Petri , Gabriel Rojas , Daniela Schreil , Klaus Drechsler , Satoshi Enzaki , Yuichiro Tsuda , Jun Inagaki
Polymer Additive Manufacturing (AM) processes are a means of producing complex parts in small numbers. Short fibers are frequently added to enhance the parts’ mechanical properties. Alignment along the extrusion path during printing results in highly anisotropic material behavior. In this study, a novel resin-based AM process (“Core-Shell Method”, developed by Toray Engineering) is investigated consisting of a vat photopolymerization printing of a non-reinforced mold (“shell”) that is subsequently filled with a short fiber filled thermally cured resin (“core”). Thermal and chemical analyses were performed and recommendations for process adjustments derived. Mechanical, microscopic and CT analyses were performed on samples produced using the Core-Shell Method and manual variants of the process as reference. The Core-Shell samples show an only slightly anisotropic material behavior. From these findings, potentials for the printing process are derived, including further modification of the fiber alignment towards either improving isotropy or selectively introducing load-path adjusted fiber orientation and reinforcement within a homogenous material mixture.
{"title":"Investigation and potentials of a novel resin-based additive manufacturing process","authors":"Leo Körber , Thomas Wettemann , Margarita Etchegaray Bello , Isabell Petri , Gabriel Rojas , Daniela Schreil , Klaus Drechsler , Satoshi Enzaki , Yuichiro Tsuda , Jun Inagaki","doi":"10.1016/j.addlet.2025.100328","DOIUrl":"10.1016/j.addlet.2025.100328","url":null,"abstract":"<div><div>Polymer Additive Manufacturing (AM) processes are a means of producing complex parts in small numbers. Short fibers are frequently added to enhance the parts’ mechanical properties. Alignment along the extrusion path during printing results in highly anisotropic material behavior. In this study, a novel resin-based AM process (“Core-Shell Method”, developed by Toray Engineering) is investigated consisting of a vat photopolymerization printing of a non-reinforced mold (“shell”) that is subsequently filled with a short fiber filled thermally cured resin (“core”). Thermal and chemical analyses were performed and recommendations for process adjustments derived. Mechanical, microscopic and CT analyses were performed on samples produced using the Core-Shell Method and manual variants of the process as reference. The Core-Shell samples show an only slightly anisotropic material behavior. From these findings, potentials for the printing process are derived, including further modification of the fiber alignment towards either improving isotropy or selectively introducing load-path adjusted fiber orientation and reinforcement within a homogenous material mixture.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"15 ","pages":"Article 100328"},"PeriodicalIF":4.7,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145362094","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 : 2025-09-30DOI: 10.1016/j.addlet.2025.100326
Jesus Rivas , Jorge Mireles , R.B. Wicker
This study investigates position accuracy, repeatability, and reproducibility of the scanning system in a metal laser powder bed fusion (PBF-LB/M) process using a novel data collection method. Deviations between Commanded and Actual scanning positions were quantified using Euclidean distance metrics across a series of builds and geometries. Results showed a build mean accuracy of 0.014 mm, increasing to 0.029 mm at the 95th percentile, with deviations reaching >0.100 mm at complex geometric paths and corners. Layers containing high scanning path deviations, showed up to 10 times more porosity than other areas, underscoring a strong correlation between scan accuracy and anomaly formation. Reproducibility testing across multiple build plate locations showed a 95th percentile deviation of 0.042 mm, with maximum deviations up to 0.080 mm. Scanning accuracy anomalies that can alter local energy density such as missing or additional hatch sections were found as a function of the build plate location, suggesting a root cause of part variability in addition to other process conditions such as gas flow. Despite high repeatability (0.004 mm mean deviation) of the scanning path, only ∼30 % of pores appeared in consistent locations, suggesting that scanner qualification alone is insufficient to explain pore final location. The study also highlighted the influence of geometry, speed, and scanning parameters in the scanning system accuracy. These findings provide new insights into how scanning system performance affects part quality and repeatability and provide a framework for incorporating scanning data metrics into future qualification protocols.
{"title":"Scanner position accuracy, repeatability, and process anomalies correlation in PBF-LB/M","authors":"Jesus Rivas , Jorge Mireles , R.B. Wicker","doi":"10.1016/j.addlet.2025.100326","DOIUrl":"10.1016/j.addlet.2025.100326","url":null,"abstract":"<div><div>This study investigates position accuracy, repeatability, and reproducibility of the scanning system in a metal laser powder bed fusion (PBF-LB/M) process using a novel data collection method. Deviations between Commanded and Actual scanning positions were quantified using Euclidean distance metrics across a series of builds and geometries. Results showed a build mean accuracy of 0.014 mm, increasing to 0.029 mm at the 95th percentile, with deviations reaching >0.100 mm at complex geometric paths and corners. Layers containing high scanning path deviations, showed up to 10 times more porosity than other areas, underscoring a strong correlation between scan accuracy and anomaly formation. Reproducibility testing across multiple build plate locations showed a 95th percentile deviation of 0.042 mm, with maximum deviations up to 0.080 mm. Scanning accuracy anomalies that can alter local energy density such as missing or additional hatch sections were found as a function of the build plate location, suggesting a root cause of part variability in addition to other process conditions such as gas flow. Despite high repeatability (0.004 mm mean deviation) of the scanning path, only ∼30 % of pores appeared in consistent locations, suggesting that scanner qualification alone is insufficient to explain pore final location. The study also highlighted the influence of geometry, speed, and scanning parameters in the scanning system accuracy. These findings provide new insights into how scanning system performance affects part quality and repeatability and provide a framework for incorporating scanning data metrics into future qualification protocols.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"15 ","pages":"Article 100326"},"PeriodicalIF":4.7,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145267140","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 : 2025-09-17DOI: 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":"2025-09-17","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 : 2025-09-13DOI: 10.1016/j.addlet.2025.100325
Jan Wegner , Lars Bruckhaus , Daniel Leonardo Schwöppe , Hanna Schönrath , Stefan Kleszczynski
Self-expandable stents are among the most implanted biomedical devices. We investigate the feasibility of additive manufacturing via laser powder bed fusion to fabricate Zr-based bulk metallic glasses into self-expandable stents to enable automated and customizable stent fabrication while implementing a novel class of materials with superior resilience compared to established alloys such as Nitinol. Three geometries are investigated with different cell dimensions. The additively manufactured stents are analyzed by µCT, SEM imaging and DSC. Overhanging geometry features show increasing crystalline defects in the amorphous matrix. However, with steep elevation angles, an amorphous fraction of up to 97.3 ± 1% is achieved in the struts. Three-point bending tests reveal large resilience of the structures, allowing for full compaction for diamond shaped cells with a height of 7 mm and an elevation angle of 77.5°, without fracture. Our findings offer preliminary evidence supporting the potential of additive manufacturing for Zr-based bulk metallic glass stents, while further studies are necessary to validate and optimize the process.
{"title":"Additively manufactured self-expandable stents from Zr-based bulk metallic glasses via laser powder bed fusion","authors":"Jan Wegner , Lars Bruckhaus , Daniel Leonardo Schwöppe , Hanna Schönrath , Stefan Kleszczynski","doi":"10.1016/j.addlet.2025.100325","DOIUrl":"10.1016/j.addlet.2025.100325","url":null,"abstract":"<div><div>Self-expandable stents are among the most implanted biomedical devices. We investigate the feasibility of additive manufacturing via laser powder bed fusion to fabricate Zr-based bulk metallic glasses into self-expandable stents to enable automated and customizable stent fabrication while implementing a novel class of materials with superior resilience compared to established alloys such as Nitinol. Three geometries are investigated with different cell dimensions. The additively manufactured stents are analyzed by µCT, SEM imaging and DSC. Overhanging geometry features show increasing crystalline defects in the amorphous matrix. However, with steep elevation angles, an amorphous fraction of up to 97.3 ± 1% is achieved in the struts. Three-point bending tests reveal large resilience of the structures, allowing for full compaction for diamond shaped cells with a height of 7 mm and an elevation angle of 77.5°, without fracture. Our findings offer preliminary evidence supporting the potential of additive manufacturing for Zr-based bulk metallic glass stents, while further studies are necessary to validate and optimize the process.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"15 ","pages":"Article 100325"},"PeriodicalIF":4.7,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145105127","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 : 2025-09-11DOI: 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":"2025-09-11","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 : 2025-09-08DOI: 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":"2025-09-08","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 : 2025-09-08DOI: 10.1016/j.addlet.2025.100322
Morgan Mosco, Christopher B. Williams, Bart Raeymaekers
Ultra-high molecular weight polyethylene (UHMWPE) is widely used in applications that need abrasion resistance, impact toughness, and chemical inertness, including bushings, prosthetic joints, naval dock bumpers, and mooring buoys. However, its high molecular weight restricts conventional processing to ram extrusion or compression molding, which require a die or mold that limits the complexity and customizability of part geometries. Additive manufacturing (AM) offers an alternative to producing complex UHMWPE parts without the need for specialized tooling. Recent advances have demonstrated AM of UHMWPE via a process chain that combines laser powder bed fusion (L-PBF) with a pressure-assisted thermal post-processing step. However, despite the critical importance in most of its applications, no information exists about wear of L-PBF printed UHMWPE compared to that of conventionally processed parts. Here, UHMWPE specimens of controlled density are produced using the L-PBF process chain and their process-structure-wear relationship is characterized. The results reveal that the steady-state wear rate decreases exponentially with increasing density and approaches that of conventionally processed benchmark specimens. This improvement is attributed to reduced porosity and corresponding increased hardness. This study provides the first process-structure-wear relationship for additively manufactured UHMWPE, and demonstrates that L-PBF can deliver wear resistance comparable to conventional processing while enabling complex, customized geometries. These findings establish a scientific and technological foundation for extending L-PBF of UHMWPE into advanced applications such as precision bushings, orthopedic components, and other high-performance parts that require both geometric freedom and excellent tribological performance.
{"title":"Wear of ultra-high molecular weight polyethylene manufactured with laser powder bed fusion","authors":"Morgan Mosco, Christopher B. Williams, Bart Raeymaekers","doi":"10.1016/j.addlet.2025.100322","DOIUrl":"10.1016/j.addlet.2025.100322","url":null,"abstract":"<div><div>Ultra-high molecular weight polyethylene (UHMWPE) is widely used in applications that need abrasion resistance, impact toughness, and chemical inertness, including bushings, prosthetic joints, naval dock bumpers, and mooring buoys. However, its high molecular weight restricts conventional processing to ram extrusion or compression molding, which require a die or mold that limits the complexity and customizability of part geometries. Additive manufacturing (AM) offers an alternative to producing complex UHMWPE parts without the need for specialized tooling. Recent advances have demonstrated AM of UHMWPE via a process chain that combines laser powder bed fusion (L-PBF) with a pressure-assisted thermal post-processing step. However, despite the critical importance in most of its applications, no information exists about wear of L-PBF printed UHMWPE compared to that of conventionally processed parts. Here, UHMWPE specimens of controlled density are produced using the L-PBF process chain and their process-structure-wear relationship is characterized. The results reveal that the steady-state wear rate decreases exponentially with increasing density and approaches that of conventionally processed benchmark specimens. This improvement is attributed to reduced porosity and corresponding increased hardness. This study provides the first process-structure-wear relationship for additively manufactured UHMWPE, and demonstrates that L-PBF can deliver wear resistance comparable to conventional processing while enabling complex, customized geometries. These findings establish a scientific and technological foundation for extending L-PBF of UHMWPE into advanced applications such as precision bushings, orthopedic components, and other high-performance parts that require both geometric freedom and excellent tribological performance.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"15 ","pages":"Article 100322"},"PeriodicalIF":4.7,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145049659","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 : 2025-08-28DOI: 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":"2025-08-28","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 : 2025-08-16DOI: 10.1016/j.addlet.2025.100318
Camille Pauzon , Rémi Daudin , Pierre Lhuissier , Xavier Bataillon , Pierre Lapouge , Pierre Hébrard , Patrice Peyre , Frédéric Coste , Lucas Varoto , Elodie Boller , Jean-Jacques Blandin
When laser powder bed fusion (LPBF) is applied to bulk metallic glasses rather than traditional crystalline alloys, one has to avoid conditions that could cause crystals to form. To achieve a balance between the porosity content and devitrification in the heat affected zone, it is common practice to process such material with a thin layer thickness, and thereby reduce the laser power necessary for melting. In this manufacturing regime, lack-of-fusion defects typically subsist. This work investigates how laser rescanning can densify metallic glasses while still ensuring their amorphous nature. Synchrotron X-ray Computed Tomography during LPBF allows imaging in situ the pores upon the glass construction. This non-destructive cutting-edge technique helps understanding the consolidation mechanism associated with rescanning and in particular its effect on layer surface roughness and the homogeneity of the powder recoating. Applied to the well-established Zr-Cu-Al-Nb grade, this work paves the way towards the adoption of less thermally stable glasses for LPBF, and the control of defect distribution. In particular, it is revealed that the hatch spacing effect is of primary importance in the production of viscous materials such as glasses, and that laser rescanning allows the surface of the deposited layer to be smoothed, improving consolidation without associated crystallisation.
{"title":"In situ porosity imaging with synchrotron X-ray tomography during laser rescanning of Zr-based metallic glass by laser powder bed fusion","authors":"Camille Pauzon , Rémi Daudin , Pierre Lhuissier , Xavier Bataillon , Pierre Lapouge , Pierre Hébrard , Patrice Peyre , Frédéric Coste , Lucas Varoto , Elodie Boller , Jean-Jacques Blandin","doi":"10.1016/j.addlet.2025.100318","DOIUrl":"10.1016/j.addlet.2025.100318","url":null,"abstract":"<div><div>When laser powder bed fusion (LPBF) is applied to bulk metallic glasses rather than traditional crystalline alloys, one has to avoid conditions that could cause crystals to form. To achieve a balance between the porosity content and devitrification in the heat affected zone, it is common practice to process such material with a thin layer thickness, and thereby reduce the laser power necessary for melting. In this manufacturing regime, lack-of-fusion defects typically subsist. This work investigates how laser rescanning can densify metallic glasses while still ensuring their amorphous nature. Synchrotron X-ray Computed Tomography during LPBF allows imaging in situ the pores upon the glass construction. This non-destructive cutting-edge technique helps understanding the consolidation mechanism associated with rescanning and in particular its effect on layer surface roughness and the homogeneity of the powder recoating. Applied to the well-established Zr-Cu-Al-Nb grade, this work paves the way towards the adoption of less thermally stable glasses for LPBF, and the control of defect distribution. In particular, it is revealed that the hatch spacing effect is of primary importance in the production of viscous materials such as glasses, and that laser rescanning allows the surface of the deposited layer to be smoothed, improving consolidation without associated crystallisation.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"15 ","pages":"Article 100318"},"PeriodicalIF":4.7,"publicationDate":"2025-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144866102","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 : 2025-08-11DOI: 10.1016/j.addlet.2025.100316
Alexander Koch , Sebastian Stammkoetter , Arvid Abel , Abootorab Chehreh , Joerg Hermsdorf , Stefan Kaierle , Frank Walther
Magnesium alloys are renowned for their high strength-to-weight ratio and low density, making them highly sought-after in the lightweight engineering sector. Among these, the high-strength magnesium alloy WE43, characterized by its Mg-4Y-3RE composition, stands out for its superior mechanical strength and thermal stability. These properties, coupled with its creep resistance, render WE43 a suitable alloy in elevated temperature applications, particularly in aerospace and automotive engineering. Despite its potential, the characterization of the load direction- and temperature-dependent deformation behavior remains incomplete for WE43, especially in additive manufacturing contexts. This study explores the quasi-static and cyclic creep properties of WE43 produced via laser-based powder bed fusion.
The research involved tensile and compression testing to evaluate quasi-static deformation and tensile-compression asymmetry. Cyclic creep behavior was studied under diverse mechanical (tension, compression) and thermal (RT, 200 °C, 300 °C) conditions by load-increase fatigue tests. Microstructural analyses based on cross-sections, XRD and computed tomography were conducted to assess manufacturing quality and identify potential inhomogeneities. The results reveal the interplay between mechanical load, temperature, and structural integrity in WE43. It could be shown that especially at 300 °C increased creep rates occure.
{"title":"Load direction and temperature impacts on cyclic creep behavior of laser-based powder bed fusion-produced WE43 magnesium alloy","authors":"Alexander Koch , Sebastian Stammkoetter , Arvid Abel , Abootorab Chehreh , Joerg Hermsdorf , Stefan Kaierle , Frank Walther","doi":"10.1016/j.addlet.2025.100316","DOIUrl":"10.1016/j.addlet.2025.100316","url":null,"abstract":"<div><div>Magnesium alloys are renowned for their high strength-to-weight ratio and low density, making them highly sought-after in the lightweight engineering sector. Among these, the high-strength magnesium alloy WE43, characterized by its Mg-4Y-3RE composition, stands out for its superior mechanical strength and thermal stability. These properties, coupled with its creep resistance, render WE43 a suitable alloy in elevated temperature applications, particularly in aerospace and automotive engineering. Despite its potential, the characterization of the load direction- and temperature-dependent deformation behavior remains incomplete for WE43, especially in additive manufacturing contexts. This study explores the quasi-static and cyclic creep properties of WE43 produced via laser-based powder bed fusion.</div><div>The research involved tensile and compression testing to evaluate quasi-static deformation and tensile-compression asymmetry. Cyclic creep behavior was studied under diverse mechanical (tension, compression) and thermal (RT, 200 °C, 300 °C) conditions by load-increase fatigue tests. Microstructural analyses based on cross-sections, XRD and computed tomography were conducted to assess manufacturing quality and identify potential inhomogeneities. The results reveal the interplay between mechanical load, temperature, and structural integrity in WE43. It could be shown that especially at 300 °C increased creep rates occure.</div></div>","PeriodicalId":72068,"journal":{"name":"Additive manufacturing letters","volume":"15 ","pages":"Article 100316"},"PeriodicalIF":4.7,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144907320","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}
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