2025
G. Tameni; D. Lago; H. Kaňková; L. Buňová; J. Kraxner; D. Galusek; D. M. Dawson; S. E. Ashbrook; E. Bernardo
Alkaline attack of boro-alumino-silicate glass: New insights of the molecular mechanism of cold consolidation and new applications Journal Article
In: Open Ceramics, vol. 21, 2025, (Cited by: 0; All Open Access, Gold Open Access).
Links | BibTeX | Tags: Materials for the environment
@article{Tameni2025,
title = {Alkaline attack of boro-alumino-silicate glass: New insights of the molecular mechanism of cold consolidation and new applications},
author = {G. Tameni and D. Lago and H. Kaňková and L. Buňová and J. Kraxner and D. Galusek and D. M. Dawson and S. E. Ashbrook and E. Bernardo},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85213004207&doi=10.1016%2fj.oceram.2024.100726&partnerID=40&md5=00a43152438bfcaacfcd8003f6f709c4},
doi = {10.1016/j.oceram.2024.100726},
year = {2025},
date = {2025-01-01},
urldate = {2025-01-01},
journal = {Open Ceramics},
volume = {21},
note = {Cited by: 0; All Open Access, Gold Open Access},
keywords = {Materials for the environment},
pubstate = {published},
tppubtype = {article}
}
V. Diamanti; H. Elsayed; E. Bernardo
3D-printed porous mullite lattice structures by hybrid direct ink writing of silicone suspension-emulsions Journal Article
In: Journal of the American Ceramic Society, vol. 108, no. 4, pp. e20290, 2025.
Abstract | Links | BibTeX | Tags: Additive Manufacturing
@article{https://doi.org/10.1111/jace.20290,
title = {3D-printed porous mullite lattice structures by hybrid direct ink writing of silicone suspension-emulsions},
author = {V. Diamanti and H. Elsayed and E. Bernardo},
url = {https://ceramics.onlinelibrary.wiley.com/doi/abs/10.1111/jace.20290},
doi = {https://doi.org/10.1111/jace.20290},
year = {2025},
date = {2025-01-01},
urldate = {2025-01-01},
journal = {Journal of the American Ceramic Society},
volume = {108},
number = {4},
pages = {e20290},
abstract = {Abstract Silicones added with nano-sized alumina particles are already known as starting materials for phase pure mullite ceramics, synthesized at quite low temperatures. The present paper deals with a fundamental upgrade, based on a novel suspension-emulsion concept, for the easy fabrication of highly porous lattice structures. An aqueous suspension of γ-Al2O3 nanoparticles in water was first distributed as emulsion within an “oily phase,” consisting of a silicone/acrylates blend, with the help of a surfactant. The mixture was later employed to fabricate highly porous structures (∼80% open porosity), by direct ink writing, that is, an extrusion-based 3D printing technology requiring specific rheological behavior of the feedstock ink. Finally, the structures were rapidly stabilized through a photo-polymerization step (configuring a form of “hybrid” direct ink writing). The presence of water also allowed the application of a freeze-curing procedure, for a second series of samples. The abundant water vapor release from the starting mixtures, upon firing (up to 1300°C), led to structures with enhanced pore interconnectivity. The freeze-curing protocol proved beneficial to the homogeneity of pore distribution and to the achievement of high strength-to-density ratios.},
keywords = {Additive Manufacturing},
pubstate = {published},
tppubtype = {article}
}
Abstract Silicones added with nano-sized alumina particles are already known as starting materials for phase pure mullite ceramics, synthesized at quite low temperatures. The present paper deals with a fundamental upgrade, based on a novel suspension-emulsion concept, for the easy fabrication of highly porous lattice structures. An aqueous suspension of γ-Al2O3 nanoparticles in water was first distributed as emulsion within an “oily phase,” consisting of a silicone/acrylates blend, with the help of a surfactant. The mixture was later employed to fabricate highly porous structures (∼80% open porosity), by direct ink writing, that is, an extrusion-based 3D printing technology requiring specific rheological behavior of the feedstock ink. Finally, the structures were rapidly stabilized through a photo-polymerization step (configuring a form of “hybrid” direct ink writing). The presence of water also allowed the application of a freeze-curing procedure, for a second series of samples. The abundant water vapor release from the starting mixtures, upon firing (up to 1300°C), led to structures with enhanced pore interconnectivity. The freeze-curing protocol proved beneficial to the homogeneity of pore distribution and to the achievement of high strength-to-density ratios.
L. Lattanzi; A. Conte; A. Sin; J. M. Garcia; C. A. Randall; P. Colombo
Cold sintering of geopolymer powders Journal Article
In: Journal of the American Ceramic Society, vol. 108, no. 4, pp. e20331, 2025.
Abstract | Links | BibTeX | Tags: Materials for the environment
@article{https://doi.org/10.1111/jace.20331,
title = {Cold sintering of geopolymer powders},
author = {L. Lattanzi and A. Conte and A. Sin and J. M. Garcia and C. A. Randall and P. Colombo},
url = {https://ceramics.onlinelibrary.wiley.com/doi/abs/10.1111/jace.20331},
doi = {https://doi.org/10.1111/jace.20331},
year = {2025},
date = {2025-01-01},
urldate = {2025-01-01},
journal = {Journal of the American Ceramic Society},
volume = {108},
number = {4},
pages = {e20331},
abstract = {Abstract Geopolymers (GP) represent a promising class of inorganic materials with diverse applications due to their properties, including high temperature resistance and strong interfacial bonding ability. They are produced through alkali activation of aluminosilicate sources, such as metakaolin or fly ashes. Despite their attractive characteristics, conventional casting methods for GP production often result in prolonged curing times and inferior mechanical properties to OPC or other benchmark materials. In this study, we investigated the feasibility of rapidly densifying GP matrices using cold sintering technology (CSP), a novel approach previously employed in ceramic systems. Through CSP, it was possible to obtain a dense body starting from GP sodium-based powder with optimal moisture content (10% wt.) under mild isostatic pressure (70 MPa) and moderate temperature (150°C) conditions, with a short duration process (10 min). The resulting products exhibited chemical stability (high resistance to boiling test), high density (> 90% theoretical density) and good mechanical properties (flexural strength equal to 30 MPa and compressive strength over 200 MPa) without requiring additional thermal treatments. SEM, EDS and NMR studies indicated that the predominant densification mechanism was likely to be homogeneous dissolutions and precipitation of the material, consistent with pressure solution creep. Dilatometric tests were performed to track the densification process in real-time and to determine the activation energy, which revealed an exceptionally low value for the system (21.7 kJ/mol). Our results demonstrate the potential of CSP as a rapid and efficient method for producing high-quality GP-based components, paving the way for their broader application in various fields.},
keywords = {Materials for the environment},
pubstate = {published},
tppubtype = {article}
}
Abstract Geopolymers (GP) represent a promising class of inorganic materials with diverse applications due to their properties, including high temperature resistance and strong interfacial bonding ability. They are produced through alkali activation of aluminosilicate sources, such as metakaolin or fly ashes. Despite their attractive characteristics, conventional casting methods for GP production often result in prolonged curing times and inferior mechanical properties to OPC or other benchmark materials. In this study, we investigated the feasibility of rapidly densifying GP matrices using cold sintering technology (CSP), a novel approach previously employed in ceramic systems. Through CSP, it was possible to obtain a dense body starting from GP sodium-based powder with optimal moisture content (10% wt.) under mild isostatic pressure (70 MPa) and moderate temperature (150°C) conditions, with a short duration process (10 min). The resulting products exhibited chemical stability (high resistance to boiling test), high density (> 90% theoretical density) and good mechanical properties (flexural strength equal to 30 MPa and compressive strength over 200 MPa) without requiring additional thermal treatments. SEM, EDS and NMR studies indicated that the predominant densification mechanism was likely to be homogeneous dissolutions and precipitation of the material, consistent with pressure solution creep. Dilatometric tests were performed to track the densification process in real-time and to determine the activation energy, which revealed an exceptionally low value for the system (21.7 kJ/mol). Our results demonstrate the potential of CSP as a rapid and efficient method for producing high-quality GP-based components, paving the way for their broader application in various fields.
S. Bhandari; T. Heim; E. De Bona; V. M. Sglavo; W. Rheinheimer; M. Biesuz; G. Franchin
Rapid processing of Al2O3 ceramics by fused filament fabrication and ultrafast high-temperature debinding and sintering Journal Article
In: Journal of Alloys and Compounds, pp. 178812, 2025, ISSN: 0925-8388.
Abstract | Links | BibTeX | Tags: Additive Manufacturing
@article{BHANDARI2025178812,
title = {Rapid processing of Al2O3 ceramics by fused filament fabrication and ultrafast high-temperature debinding and sintering},
author = {S. Bhandari and T. Heim and E. De Bona and V. M. Sglavo and W. Rheinheimer and M. Biesuz and G. Franchin},
url = {https://www.sciencedirect.com/science/article/pii/S0925838825003706},
doi = {https://doi.org/10.1016/j.jallcom.2025.178812},
issn = {0925-8388},
year = {2025},
date = {2025-01-01},
urldate = {2025-01-01},
journal = {Journal of Alloys and Compounds},
pages = {178812},
abstract = {Fused filament fabrication (FFF) is widely used for ceramic prototyping due to its compatibility with low-cost, custom-made printers designed for polymers. However, the bottleneck of the whole process lies in the slow thermal debinding and sintering that are usually employed to obtain dense and defect-free ceramics. In this study, a filament with ~79wt.% alumina powder in a thermoplastic binder was used to print gyroid structures with nozzle diameters of 0.4, 0.6, and 0.8mm. The components were at first partially solvent-debinded (acetone) and thereafter thermally debinded and consolidated in a single step (60s) by ultra-fast high-temperature sintering. Samples printed with a 0.4mm nozzle diameter resisted the ultra-rapid heating (UHS) and cooling rates (~103K/min), whereas some defects appear when considering larger nozzle size. On the other hand, all samples either cracked or shattered into pieces when fast-fired in air, highlighting the relevance of the thermal debinding atmosphere. Moreover, the densification upon UHS was largely improved compared to conventional sintering while retaining a finer grain size. This work provides a guideline for the rapid debinding and firing of fused filament fabricated ceramics and could be easily extended to other ceramic systems.},
keywords = {Additive Manufacturing},
pubstate = {published},
tppubtype = {article}
}
Fused filament fabrication (FFF) is widely used for ceramic prototyping due to its compatibility with low-cost, custom-made printers designed for polymers. However, the bottleneck of the whole process lies in the slow thermal debinding and sintering that are usually employed to obtain dense and defect-free ceramics. In this study, a filament with ~79wt.% alumina powder in a thermoplastic binder was used to print gyroid structures with nozzle diameters of 0.4, 0.6, and 0.8mm. The components were at first partially solvent-debinded (acetone) and thereafter thermally debinded and consolidated in a single step (60s) by ultra-fast high-temperature sintering. Samples printed with a 0.4mm nozzle diameter resisted the ultra-rapid heating (UHS) and cooling rates (~103K/min), whereas some defects appear when considering larger nozzle size. On the other hand, all samples either cracked or shattered into pieces when fast-fired in air, highlighting the relevance of the thermal debinding atmosphere. Moreover, the densification upon UHS was largely improved compared to conventional sintering while retaining a finer grain size. This work provides a guideline for the rapid debinding and firing of fused filament fabricated ceramics and could be easily extended to other ceramic systems.
S. Bhandari; O. Hanzel; M. Kermani; V. M. Sglavo; M. Biesuz; G. Franchin
Rapid debinding and sintering of alumina ceramics fabricated by direct ink writing Journal Article
In: Journal of the European Ceramic Society, vol. 45, no. 5, pp. 117144, 2025, ISSN: 0955-2219.
Abstract | Links | BibTeX | Tags: Additive Manufacturing
@article{BHANDARI2025117144,
title = {Rapid debinding and sintering of alumina ceramics fabricated by direct ink writing},
author = {S. Bhandari and O. Hanzel and M. Kermani and V. M. Sglavo and M. Biesuz and G. Franchin},
url = {https://www.sciencedirect.com/science/article/pii/S0955221924010173},
doi = {https://doi.org/10.1016/j.jeurceramsoc.2024.117144},
issn = {0955-2219},
year = {2025},
date = {2025-01-01},
urldate = {2025-01-01},
journal = {Journal of the European Ceramic Society},
volume = {45},
number = {5},
pages = {117144},
abstract = {Direct ink writing (DIW) is a widely used additive manufacturing technique to fabricate complex-shaped ceramics. Unlike vat photopolymerization or fused filament fabrication, the limited amount of binder in DIW facilitates rapid debinding. In this study, alumina inks with suitable rheology were prepared with two different ceramic loadings (42.8 vol% and 48.1 vol%). Subsequently, log-pile structures were printed using two different nozzle diameters (0.41 mm and 0.84 mm). The fabricated samples were dried at room temperature and subjected to different rapid sintering procedures: ultra-fast high temperature sintering (UHS), pressureless spark plasma sintering (PSPS) and fast-firing (FF). Both UHS and PSPS successfully densified the samples in Ar without any defects. Conversely, the fast-firing in air resulted in some cracks, with the intensity of failures increasing with the nozzle size. UHS and PSPS allowed for nearly fully dense materials with refined microstructure which are not achievable by conventional heating.},
keywords = {Additive Manufacturing},
pubstate = {published},
tppubtype = {article}
}
Direct ink writing (DIW) is a widely used additive manufacturing technique to fabricate complex-shaped ceramics. Unlike vat photopolymerization or fused filament fabrication, the limited amount of binder in DIW facilitates rapid debinding. In this study, alumina inks with suitable rheology were prepared with two different ceramic loadings (42.8 vol% and 48.1 vol%). Subsequently, log-pile structures were printed using two different nozzle diameters (0.41 mm and 0.84 mm). The fabricated samples were dried at room temperature and subjected to different rapid sintering procedures: ultra-fast high temperature sintering (UHS), pressureless spark plasma sintering (PSPS) and fast-firing (FF). Both UHS and PSPS successfully densified the samples in Ar without any defects. Conversely, the fast-firing in air resulted in some cracks, with the intensity of failures increasing with the nozzle size. UHS and PSPS allowed for nearly fully dense materials with refined microstructure which are not achievable by conventional heating.
S. Bhandari; G. Vajpayee; L. Lemos Silva; M. Hinterstein; G. Franchin; P. Colombo
A review on additive manufacturing of piezoelectric ceramics: From feedstock development to properties of sintered parts Journal Article
In: Materials Science and Engineering: R: Reports, vol. 162, pp. 100877, 2025, ISSN: 0927-796X.
Abstract | Links | BibTeX | Tags: Additive Manufacturing
@article{BHANDARI2025100877,
title = {A review on additive manufacturing of piezoelectric ceramics: From feedstock development to properties of sintered parts},
author = {S. Bhandari and G. Vajpayee and L. Lemos Silva and M. Hinterstein and G. Franchin and P. Colombo},
url = {https://www.sciencedirect.com/science/article/pii/S0927796X24001074},
doi = {https://doi.org/10.1016/j.mser.2024.100877},
issn = {0927-796X},
year = {2025},
date = {2025-01-01},
urldate = {2025-01-01},
journal = {Materials Science and Engineering: R: Reports},
volume = {162},
pages = {100877},
abstract = {Piezoelectric ceramics are extensively used in several engineering applications in the field of sensors, actuators, energy harvesting, biomedical, and many more. Traditional ways of manufacturing piezoelectric devices result in better piezoelectric/ferroelectric performance. However, they are restricted to only simple shapes. With the widespread influence of additive manufacturing (AM), it is now possible to fabricate complex structures which were not possible by conventional technologies. In order to fabricate such complex structures with precision, it is necessary to understand in detail the factors influencing the feedstock preparation and the challenges associated with different AM technologies. With an emphasis on the most commonly used AM techniques (direct ink writing, fused filament fabrication, vat photopolymerization, binder jetting, and selective laser sintering) for fabricating ceramic parts, this review paper intends to provide a deep insight into the factors affecting the feedstock preparation as well as post-processing conditions required to develop a high-performance piezoelectric device. The summarized tables detailing the various piezoelectric ceramic compositions and additives or ingredients used in formulating a printable feedstock, along with the optimum printing and post-processing conditions, will aid the readers in developing their own printable formulations and determining the best post-processing parameters to achieve the best performance out of the fabricated piezoelectric device. The advantages and disadvantages of the AM technologies are analyzed with specific reference to piezoceramic materials and the remaining challenges that require further research are emphasized. Furthermore, with the ongoing and continuous developments in additive manufacturing of piezoelectric materials, it is expected that such advancements will progressively transition towards commercialization, with the ultimate goal of widely incorporating additively manufactured devices into practical applications.},
keywords = {Additive Manufacturing},
pubstate = {published},
tppubtype = {article}
}
Piezoelectric ceramics are extensively used in several engineering applications in the field of sensors, actuators, energy harvesting, biomedical, and many more. Traditional ways of manufacturing piezoelectric devices result in better piezoelectric/ferroelectric performance. However, they are restricted to only simple shapes. With the widespread influence of additive manufacturing (AM), it is now possible to fabricate complex structures which were not possible by conventional technologies. In order to fabricate such complex structures with precision, it is necessary to understand in detail the factors influencing the feedstock preparation and the challenges associated with different AM technologies. With an emphasis on the most commonly used AM techniques (direct ink writing, fused filament fabrication, vat photopolymerization, binder jetting, and selective laser sintering) for fabricating ceramic parts, this review paper intends to provide a deep insight into the factors affecting the feedstock preparation as well as post-processing conditions required to develop a high-performance piezoelectric device. The summarized tables detailing the various piezoelectric ceramic compositions and additives or ingredients used in formulating a printable feedstock, along with the optimum printing and post-processing conditions, will aid the readers in developing their own printable formulations and determining the best post-processing parameters to achieve the best performance out of the fabricated piezoelectric device. The advantages and disadvantages of the AM technologies are analyzed with specific reference to piezoceramic materials and the remaining challenges that require further research are emphasized. Furthermore, with the ongoing and continuous developments in additive manufacturing of piezoelectric materials, it is expected that such advancements will progressively transition towards commercialization, with the ultimate goal of widely incorporating additively manufactured devices into practical applications.
2024
S. M. Carturan; H. Skliarova; G. Franchin; G. Bombardelli; A. Zanini; F. E. P. Andrades; J. C. Delgado Alvarez; S. Moretto; G. Maggioni; W. Raniero; D. Maniglio; A. P. Caricato; A. Quaranta
Additive manufacturing of high-performance, flexible 3D siloxane-based scintillators through the sol-gel route Journal Article
In: Applied Materials Today, vol. 39, 2024, ISSN: 2352-9407.
Links | BibTeX | Tags: Additive Manufacturing
@article{Carturan2024,
title = {Additive manufacturing of high-performance, flexible 3D siloxane-based scintillators through the sol-gel route},
author = {S. M. Carturan and H. Skliarova and G. Franchin and G. Bombardelli and A. Zanini and F. E. P. Andrades and J. C. Delgado Alvarez and S. Moretto and G. Maggioni and W. Raniero and D. Maniglio and A. P. Caricato and A. Quaranta},
doi = {10.1016/j.apmt.2024.102313},
issn = {2352-9407},
year = {2024},
date = {2024-08-00},
urldate = {2024-08-00},
journal = {Applied Materials Today},
volume = {39},
publisher = {Elsevier BV},
keywords = {Additive Manufacturing},
pubstate = {published},
tppubtype = {article}
}
A. Zanini; P. Amador Celdran; O. Walter; S. M. Carturan; J. Boshoven; A. Bulgheroni; L. Biasetto; M. Manzolaro; R. Eloirdi; S. Corradetti; G. Franchin
First Structured Uranium‐Based Monoliths Produced via Vat Photopolymerization for Nuclear Applications Journal Article
In: Adv Funct Materials, 2024, ISSN: 1616-3028.
Abstract | Links | BibTeX | Tags: Additive Manufacturing
@article{Zanini2024,
title = {First Structured Uranium‐Based Monoliths Produced via Vat Photopolymerization for Nuclear Applications},
author = {A. Zanini and P. Amador Celdran and O. Walter and S. M. Carturan and J. Boshoven and A. Bulgheroni and L. Biasetto and M. Manzolaro and R. Eloirdi and S. Corradetti and G. Franchin},
doi = {10.1002/adfm.202406916},
issn = {1616-3028},
year = {2024},
date = {2024-06-20},
urldate = {2024-06-20},
journal = {Adv Funct Materials},
publisher = {Wiley},
abstract = {Uranium plays an unquestionable role in the framework of nuclear physics, biology, and radiopharmacy. Moreover, uranyl ion UO2 2+ offers an immense variety of applications due to the unique photosensitivity of its complexes. The excited state of uranyl cation is indeed accessible under ultraviolet‐visible (UV–vis) light, readily producing radical species UO2 2+ upon light irradiation. Herein, an innovative synthesis protocol is presented to explore the use of uranyl cations as photocatalyst systems for photocurable sol–gel‐based formulations, coupling the photochemical reactions of uranyl cations with photopolymerization‐based additive manufacturing processes. Additive manufacturing has nowadays revolutionized the production of complex structures with arbitrary geometries and has opened up enticing opportunities for innovative technological breakthroughs and highly tailorable systems. The fabrication of micro‐architected components is shown via vat photopolymerization, namely, the Digital Light Processing technique, and ‐3D) printed parts are converted into uranium dicarbide (UC2)/carbon nanocomposite upon carbothermal reduction. This uranyl‐mediated additive manufacturing process constitutes the first application of the synergistic role of uranyl motifs in a photopolymer platform, demonstrating for the first time the possibility to directly pattern uranium‐based materials in complex structures.},
keywords = {Additive Manufacturing},
pubstate = {published},
tppubtype = {article}
}
Uranium plays an unquestionable role in the framework of nuclear physics, biology, and radiopharmacy. Moreover, uranyl ion UO2 2+ offers an immense variety of applications due to the unique photosensitivity of its complexes. The excited state of uranyl cation is indeed accessible under ultraviolet‐visible (UV–vis) light, readily producing radical species UO2 2+ upon light irradiation. Herein, an innovative synthesis protocol is presented to explore the use of uranyl cations as photocatalyst systems for photocurable sol–gel‐based formulations, coupling the photochemical reactions of uranyl cations with photopolymerization‐based additive manufacturing processes. Additive manufacturing has nowadays revolutionized the production of complex structures with arbitrary geometries and has opened up enticing opportunities for innovative technological breakthroughs and highly tailorable systems. The fabrication of micro‐architected components is shown via vat photopolymerization, namely, the Digital Light Processing technique, and ‐3D) printed parts are converted into uranium dicarbide (UC2)/carbon nanocomposite upon carbothermal reduction. This uranyl‐mediated additive manufacturing process constitutes the first application of the synergistic role of uranyl motifs in a photopolymer platform, demonstrating for the first time the possibility to directly pattern uranium‐based materials in complex structures.
S. Bhandari; O. Hanzel; P. Veteška; M. Janek; E. De Bona; V. M. Sglavo; M. Biesuz; G. Franchin
From rapid prototyping to rapid firing: on the feasibility of high‐speed production for complex BaTiO3 components Journal Article
In: J Am Ceram Soc., 2024, ISSN: 1551-2916.
Abstract | Links | BibTeX | Tags: Additive Manufacturing
@article{Bhandari2024,
title = {From rapid prototyping to rapid firing: on the feasibility of high‐speed production for complex BaTiO3 components},
author = {S. Bhandari and O. Hanzel and P. Veteška and M. Janek and E. De Bona and V. M. Sglavo and M. Biesuz and G. Franchin},
doi = {10.1111/jace.19950},
issn = {1551-2916},
year = {2024},
date = {2024-06-14},
urldate = {2024-06-14},
journal = {J Am Ceram Soc.},
publisher = {Wiley},
abstract = {Direct ink writing (DIW) is an attractive additive manufacturing (AM) technology because of its simplicity, production speed, and feedstock flexibility; in addition, the use of a limited amount of binder makes the subsequent thermal debinding process easy. Nevertheless, the conventional approach to debind and sinter AMed components remains extremely slow, representing a bottleneck in the manufacturing process. In order to address such limitation, we explored different rapid sintering strategies: ultrafast high‐temperature sintering (UHS), pressureless spark plasma sintering (P‐SPS), and fast firing (FF), for the densification of BaTiO<jats:sub>3</jats:sub> components fabricated by DIW, one of the widely used lead‐free piezoceramics. All sintering technologies allow debinding and sintering of crack‐free components in a few minutes instead of several hours. The final density and microstructure are strongly dependent on the sintering atmosphere (inert for UHS and P‐SPS, air for FF) and a maximum relative density of only ≈72% was obtained when firing occurred in an inert environment, irrespective of the sintering technique (UHS and P‐SPS). An undesired phase transition from tetragonal to hexagonal BaTiO<jats:sub>3</jats:sub> was also observed upon UHS and ‐PSPS. On the contrary, FF in air yielded a density of about 95% in a few minutes while maintaining the desired tetragonal polymorph. The results provide proof of feasibility for rapid processing of BaTiO<jats:sub>3</jats:sub> components obtained by DIW.},
keywords = {Additive Manufacturing},
pubstate = {published},
tppubtype = {article}
}
Direct ink writing (DIW) is an attractive additive manufacturing (AM) technology because of its simplicity, production speed, and feedstock flexibility; in addition, the use of a limited amount of binder makes the subsequent thermal debinding process easy. Nevertheless, the conventional approach to debind and sinter AMed components remains extremely slow, representing a bottleneck in the manufacturing process. In order to address such limitation, we explored different rapid sintering strategies: ultrafast high‐temperature sintering (UHS), pressureless spark plasma sintering (P‐SPS), and fast firing (FF), for the densification of BaTiO<jats:sub>3</jats:sub> components fabricated by DIW, one of the widely used lead‐free piezoceramics. All sintering technologies allow debinding and sintering of crack‐free components in a few minutes instead of several hours. The final density and microstructure are strongly dependent on the sintering atmosphere (inert for UHS and P‐SPS, air for FF) and a maximum relative density of only ≈72% was obtained when firing occurred in an inert environment, irrespective of the sintering technique (UHS and P‐SPS). An undesired phase transition from tetragonal to hexagonal BaTiO<jats:sub>3</jats:sub> was also observed upon UHS and ‐PSPS. On the contrary, FF in air yielded a density of about 95% in a few minutes while maintaining the desired tetragonal polymorph. The results provide proof of feasibility for rapid processing of BaTiO<jats:sub>3</jats:sub> components obtained by DIW.
A. De Marzi; S. Diener; A. Campagnolo; G. Meneghetti; N. Katsikis; P. Colombo; G. Franchin
Ultra-lightweight silicon nitride truss-based structures fabricated via UV-assisted robot direct ink writing Journal Article
In: Materials & Design, pp. 113092, 2024, ISSN: 0264-1275.
Abstract | Links | BibTeX | Tags: Additive Manufacturing
@article{DEMARZI2024113092,
title = {Ultra-lightweight silicon nitride truss-based structures fabricated via UV-assisted robot direct ink writing},
author = {A. De Marzi and S. Diener and A. Campagnolo and G. Meneghetti and N. Katsikis and P. Colombo and G. Franchin},
url = {https://www.sciencedirect.com/science/article/pii/S0264127524004660},
doi = {https://doi.org/10.1016/j.matdes.2024.113092},
issn = {0264-1275},
year = {2024},
date = {2024-06-14},
urldate = {2024-06-14},
journal = {Materials & Design},
pages = {113092},
abstract = {Additive manufacturing techniques have gone beyond their reputation for rapid prototype production and are increasingly adopted for the manufacture of functional components comprising high-end materials and intricate lattice structures. Silicon nitride, renowned for its exceptional mechanical properties and thermal stability, has emerged as a promising candidate for lightweight structural applications. Nonetheless, its high refractive index and density have limited the fabrication of highly complex structures using extrusion and photopolymerization based techniques. In this work, a highly reactive silicon nitride-based ink with high solid loading is developed for the fabrication of ultra-lightweight, truss-based structures. By employing a robot UV-assisted direct ink writing process, it is possible to control the printing head orientation, thus overcoming the limited curing depth of silicon nitride-based inks. The failure behavior of the sintered lattice beam structures under 4-point bending loading has been modeled by applying a linear elastic fracture mechanics (LEFM) based approach to the results of finite element (FE) simulations.},
keywords = {Additive Manufacturing},
pubstate = {published},
tppubtype = {article}
}
Additive manufacturing techniques have gone beyond their reputation for rapid prototype production and are increasingly adopted for the manufacture of functional components comprising high-end materials and intricate lattice structures. Silicon nitride, renowned for its exceptional mechanical properties and thermal stability, has emerged as a promising candidate for lightweight structural applications. Nonetheless, its high refractive index and density have limited the fabrication of highly complex structures using extrusion and photopolymerization based techniques. In this work, a highly reactive silicon nitride-based ink with high solid loading is developed for the fabrication of ultra-lightweight, truss-based structures. By employing a robot UV-assisted direct ink writing process, it is possible to control the printing head orientation, thus overcoming the limited curing depth of silicon nitride-based inks. The failure behavior of the sintered lattice beam structures under 4-point bending loading has been modeled by applying a linear elastic fracture mechanics (LEFM) based approach to the results of finite element (FE) simulations.
K. Huang; G. Franchin; P. Colombo
Volumetric Additive Manufacturing of SiOC by Xolography Journal Article
In: Small, 2024, ISSN: 1613-6829.
Abstract | Links | BibTeX | Tags: Additive Manufacturing, Polymer-derived ceramics
@article{Huang2024,
title = {Volumetric Additive Manufacturing of SiOC by Xolography},
author = {K. Huang and G. Franchin and P. Colombo},
doi = {10.1002/smll.202402356},
issn = {1613-6829},
year = {2024},
date = {2024-05-10},
urldate = {2024-05-10},
journal = {Small},
publisher = {Wiley},
abstract = {Additive manufacturing (AM) of ceramics has significantly contributed to advancements in ceramic fabrication, solving some of the difficulties of conventional ceramic processing and providing additional possibilities for the structure and function of components. However, defects induced by the layer‐by‐layer approach on which traditional AM techniques are based still constitute a challenge to address. This study presents the volumetric AM of a SiOC ceramic from a preceramic polymer using xolography, a linear volumetric AM process that allows to avoid the staircase effect typical of other vat photopolymerization techniques. Besides optimizing the trade‐off between preceramic polymer content and transmittance, a pore generator is introduced to create transient channels for gas release before decomposition of the organic constituents and moieties, resulting in crack‐free solid ceramic structures even at low ceramic yield. Formulation optimization alleviated sinking of printed parts during printing and prevented shape distortion. Complex solid and porous ceramic structures with a smooth surface and sharp features are fabricated under the optimized parameters. This work provides a new method for the AM of ceramics at µm/mm scale with high surface quality and large geometry variety in an efficient way, opening the possibility for applications in fields such as micromechanical systems and microelectronic components.},
keywords = {Additive Manufacturing, Polymer-derived ceramics},
pubstate = {published},
tppubtype = {article}
}
Additive manufacturing (AM) of ceramics has significantly contributed to advancements in ceramic fabrication, solving some of the difficulties of conventional ceramic processing and providing additional possibilities for the structure and function of components. However, defects induced by the layer‐by‐layer approach on which traditional AM techniques are based still constitute a challenge to address. This study presents the volumetric AM of a SiOC ceramic from a preceramic polymer using xolography, a linear volumetric AM process that allows to avoid the staircase effect typical of other vat photopolymerization techniques. Besides optimizing the trade‐off between preceramic polymer content and transmittance, a pore generator is introduced to create transient channels for gas release before decomposition of the organic constituents and moieties, resulting in crack‐free solid ceramic structures even at low ceramic yield. Formulation optimization alleviated sinking of printed parts during printing and prevented shape distortion. Complex solid and porous ceramic structures with a smooth surface and sharp features are fabricated under the optimized parameters. This work provides a new method for the AM of ceramics at µm/mm scale with high surface quality and large geometry variety in an efficient way, opening the possibility for applications in fields such as micromechanical systems and microelectronic components.
E. Cepollaro; S. Cimino; M. D'Agostini; N. Gargiulo; G. Franchin; L. Lisi
3D-Printed Monoliths Based on Cu-Exchanged SSZ-13 as Catalyst for SCR of NOx Journal Article
In: Catalysts, vol. 14, iss. 1, no. 85, 2024.
Abstract | Links | BibTeX | Tags: Additive Manufacturing, Materials for the environment
@article{nokey,
title = {3D-Printed Monoliths Based on Cu-Exchanged SSZ-13 as Catalyst for SCR of NOx},
author = {E. Cepollaro and S. Cimino and M. D'Agostini and N. Gargiulo and G. Franchin and L. Lisi},
doi = {10.3390/catal14010085},
year = {2024},
date = {2024-01-19},
urldate = {2024-01-19},
journal = {Catalysts},
volume = {14},
number = {85},
issue = {1},
abstract = {Monoliths manufactured by Direct Ink Writing containing 60% SSZ-13 (SiO2/Al2O3 = 23) and SiO2 with 10% laponite as a binder were investigated as self-standing structured catalysts for NH3-SCR of NOx after a short (4 h) and prolonged (24 h) ion exchange with copper and then compared with pure SSZ-13 exchanged under the same conditions. The catalysts were characterized by morphological (XRD and SEM), textural (BET and pore size distribution), chemical (ICP-MS), red-ox (H2-TPR), and surface (NH3-TPD) analyses. The silica-based binder uniformly covered the SSZ-13 particles, and copper was uniformly distributed as well. The main features of the pure Cu-exchanged SSZ-13 zeolite were preserved in the composite monoliths with a negligible contribution of the binder fraction. NH3-SCR tests, carried out on both monolithic and powdered samples in the temperature range of 70–550 °C, showed that composite monoliths provided very good activity, and that the intrinsic activity of SSZ-13 was enhanced by the hierarchical structure of the composite material.},
keywords = {Additive Manufacturing, Materials for the environment},
pubstate = {published},
tppubtype = {article}
}
Monoliths manufactured by Direct Ink Writing containing 60% SSZ-13 (SiO2/Al2O3 = 23) and SiO2 with 10% laponite as a binder were investigated as self-standing structured catalysts for NH3-SCR of NOx after a short (4 h) and prolonged (24 h) ion exchange with copper and then compared with pure SSZ-13 exchanged under the same conditions. The catalysts were characterized by morphological (XRD and SEM), textural (BET and pore size distribution), chemical (ICP-MS), red-ox (H2-TPR), and surface (NH3-TPD) analyses. The silica-based binder uniformly covered the SSZ-13 particles, and copper was uniformly distributed as well. The main features of the pure Cu-exchanged SSZ-13 zeolite were preserved in the composite monoliths with a negligible contribution of the binder fraction. NH3-SCR tests, carried out on both monolithic and powdered samples in the temperature range of 70–550 °C, showed that composite monoliths provided very good activity, and that the intrinsic activity of SSZ-13 was enhanced by the hierarchical structure of the composite material.
F. Cammelli; G. Tameni; E. Bernardo
Sustainable stabilization of waste foundry sands in alkali activated glass-based matrices Journal Article
In: Case Studies in Construction Materials, vol. 21, 2024, (Cited by: 0; All Open Access, Hybrid Gold Open Access).
Links | BibTeX | Tags: Materials for the environment
@article{Cammelli2024,
title = {Sustainable stabilization of waste foundry sands in alkali activated glass-based matrices},
author = {F. Cammelli and G. Tameni and E. Bernardo},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85199569634&doi=10.1016%2fj.cscm.2024.e03538&partnerID=40&md5=b9f2019609974f651aa1945049786175},
doi = {10.1016/j.cscm.2024.e03538},
year = {2024},
date = {2024-01-01},
urldate = {2024-01-01},
journal = {Case Studies in Construction Materials},
volume = {21},
note = {Cited by: 0; All Open Access, Hybrid Gold Open Access},
keywords = {Materials for the environment},
pubstate = {published},
tppubtype = {article}
}
D. Lago; G. Tameni; J. Kraxner; D. Galusek; E. Bernardo
Cesium stabilization by engineered alkaline attack of glass for pharmaceutical containers Journal Article
In: Materials Letters, vol. 372, 2024, (Cited by: 0).
Links | BibTeX | Tags: Materials for the environment
@article{Lago2024b,
title = {Cesium stabilization by engineered alkaline attack of glass for pharmaceutical containers},
author = {D. Lago and G. Tameni and J. Kraxner and D. Galusek and E. Bernardo},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85199962040&doi=10.1016%2fj.matlet.2024.137097&partnerID=40&md5=0cf00a128d65142220b095702ecb01d4},
doi = {10.1016/j.matlet.2024.137097},
year = {2024},
date = {2024-01-01},
urldate = {2024-01-01},
journal = {Materials Letters},
volume = {372},
note = {Cited by: 0},
keywords = {Materials for the environment},
pubstate = {published},
tppubtype = {article}
}
D. Lago; G. Tameni; F. Zorzi; J. Kraxner; D. Galusek; E. Bernardo
Novel cesium immobilization by alkali activation and cold consolidation of waste pharmaceutical glass Journal Article
In: Journal of Cleaner Production, vol. 461, 2024, (Cited by: 1; All Open Access, Hybrid Gold Open Access).
Links | BibTeX | Tags: Materials for the environment
@article{Lago2024,
title = {Novel cesium immobilization by alkali activation and cold consolidation of waste pharmaceutical glass},
author = {D. Lago and G. Tameni and F. Zorzi and J. Kraxner and D. Galusek and E. Bernardo},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85194095471&doi=10.1016%2fj.jclepro.2024.142673&partnerID=40&md5=954ab91e99c2519d54b0063aedd6394b},
doi = {10.1016/j.jclepro.2024.142673},
year = {2024},
date = {2024-01-01},
urldate = {2024-01-01},
journal = {Journal of Cleaner Production},
volume = {461},
note = {Cited by: 1; All Open Access, Hybrid Gold Open Access},
keywords = {Materials for the environment},
pubstate = {published},
tppubtype = {article}
}
V. Diamanti; H. Elsayed; E. Bernardo
Hybrid direct ink writing of bioglass-calcite-carbon composite scaffolds supported by novel silicone-based emulsions Journal Article
In: Ceramics International, vol. 50, no. 24, Part B, pp. 53646-53654, 2024, ISSN: 0272-8842.
Abstract | Links | BibTeX | Tags: Additive Manufacturing
@article{DIAMANTI202453646,
title = {Hybrid direct ink writing of bioglass-calcite-carbon composite scaffolds supported by novel silicone-based emulsions},
author = {V. Diamanti and H. Elsayed and E. Bernardo},
url = {https://www.sciencedirect.com/science/article/pii/S0272884224047369},
doi = {https://doi.org/10.1016/j.ceramint.2024.10.215},
issn = {0272-8842},
year = {2024},
date = {2024-01-01},
urldate = {2024-01-01},
journal = {Ceramics International},
volume = {50},
number = {24, Part B},
pages = {53646-53654},
abstract = {70S30C (70 mol% SiO2, 30 % CaO) bioglass is one of the most promising bioceramics for bone tissue engineering. We discuss the feasibility of 70S30C bioglass/calcite/carbon composites derived from novel silicone-based emulsions, leading to highly porous lattice scaffolds. These are produced by direct ink writing (DIW) 3D printing, followed by ceramic conversion at 700 °C in flowing nitrogen. The emulsions consisted of droplets of concentrated calcium nitrate aqueous solution incorporated into blends of H44 commercial polysiloxane and photocurable acrylate resin. This formulation offered unprecedented opportunities in both synthesis and shaping. Specifically, the homogeneous dispersion of the CaO precursor in silicone enabled a uniform SiO2/CaO distribution, favoring the formation of a glass matrix. Additionally, the acrylate component and water content allowed for tuning of the microstructure both immediately after printing and upon firing. Photopolymerization of acrylates consolidated the printed bodies (configuring a ‘hybrid DIW’) after extrusion, while water evaporation enhanced gas evolution during ceramic conversion, promoting pore interconnectivity.},
keywords = {Additive Manufacturing},
pubstate = {published},
tppubtype = {article}
}
70S30C (70 mol% SiO2, 30 % CaO) bioglass is one of the most promising bioceramics for bone tissue engineering. We discuss the feasibility of 70S30C bioglass/calcite/carbon composites derived from novel silicone-based emulsions, leading to highly porous lattice scaffolds. These are produced by direct ink writing (DIW) 3D printing, followed by ceramic conversion at 700 °C in flowing nitrogen. The emulsions consisted of droplets of concentrated calcium nitrate aqueous solution incorporated into blends of H44 commercial polysiloxane and photocurable acrylate resin. This formulation offered unprecedented opportunities in both synthesis and shaping. Specifically, the homogeneous dispersion of the CaO precursor in silicone enabled a uniform SiO2/CaO distribution, favoring the formation of a glass matrix. Additionally, the acrylate component and water content allowed for tuning of the microstructure both immediately after printing and upon firing. Photopolymerization of acrylates consolidated the printed bodies (configuring a ‘hybrid DIW’) after extrusion, while water evaporation enhanced gas evolution during ceramic conversion, promoting pore interconnectivity.
L. Biasetto; V. Gastaldi; H. Elsayed
Co-extrusion of highly loaded feedstocks for fabrication of stainless steel-bioceramic core-shell structures Journal Article
In: Journal of Materials Research and Technology, vol. 33, pp. 6820-6830, 2024, ISSN: 2238-7854.
Abstract | Links | BibTeX | Tags: Additive Manufacturing
@article{BIASETTO20246820,
title = {Co-extrusion of highly loaded feedstocks for fabrication of stainless steel-bioceramic core-shell structures},
author = {L. Biasetto and V. Gastaldi and H. Elsayed},
url = {https://www.sciencedirect.com/science/article/pii/S2238785424025250},
doi = {https://doi.org/10.1016/j.jmrt.2024.10.255},
issn = {2238-7854},
year = {2024},
date = {2024-01-01},
urldate = {2024-01-01},
journal = {Journal of Materials Research and Technology},
volume = {33},
pages = {6820-6830},
abstract = {Co-extrusion of multi-materials structures shows technological challenges and opportunities. Filaments made of a metallic core and a ceramic shell are one example of how structural and functional features can be combined in a single component to provide a synergic effect. In this work, we focused on the fabrication of shell and core-shell scaffolds for potential applications as bone substitutes. Stainless steel 316L was selected for the core material, whilst in situ synthesized sphene (CaTiSiO5) bioactive ceramic was selected as a shell. The combination of a ductile core and a bioactive ceramic, so as scaffolds made of empty struts may represent a new generation of bone substitutes with mechanical properties closer to the ones of natural bone so as with improved bioactivity. Therefore, formulated inks were co-extruded in one step using a customized printing set-up. Microstructural and mechanical properties were investigated on shell and core-shell filaments and 3D structures. Shell bioceramics scaffolds possessed high porosity and target compression strength values. The sintering environment at the core-shell interface caused severe 316L oxidation thus compromising the ductility of the metallic part, however compression strength increased of 53% compared to shell structures.},
keywords = {Additive Manufacturing},
pubstate = {published},
tppubtype = {article}
}
Co-extrusion of multi-materials structures shows technological challenges and opportunities. Filaments made of a metallic core and a ceramic shell are one example of how structural and functional features can be combined in a single component to provide a synergic effect. In this work, we focused on the fabrication of shell and core-shell scaffolds for potential applications as bone substitutes. Stainless steel 316L was selected for the core material, whilst in situ synthesized sphene (CaTiSiO5) bioactive ceramic was selected as a shell. The combination of a ductile core and a bioactive ceramic, so as scaffolds made of empty struts may represent a new generation of bone substitutes with mechanical properties closer to the ones of natural bone so as with improved bioactivity. Therefore, formulated inks were co-extruded in one step using a customized printing set-up. Microstructural and mechanical properties were investigated on shell and core-shell filaments and 3D structures. Shell bioceramics scaffolds possessed high porosity and target compression strength values. The sintering environment at the core-shell interface caused severe 316L oxidation thus compromising the ductility of the metallic part, however compression strength increased of 53% compared to shell structures.
A. W. Ourgessa; J. Kraxner; H. Elsayed; D. Galusek; E. Bernardo
Sustainable construction materials from alkali-activated waste fiberglass and waste refractory Journal Article
In: Open Ceramics, vol. 20, pp. 100678, 2024, ISSN: 2666-5395.
Abstract | Links | BibTeX | Tags: Materials for the environment
@article{OURGESSA2024100678,
title = {Sustainable construction materials from alkali-activated waste fiberglass and waste refractory},
author = {A. W. Ourgessa and J. Kraxner and H. Elsayed and D. Galusek and E. Bernardo},
url = {https://www.sciencedirect.com/science/article/pii/S2666539524001421},
doi = {https://doi.org/10.1016/j.oceram.2024.100678},
issn = {2666-5395},
year = {2024},
date = {2024-01-01},
urldate = {2024-01-01},
journal = {Open Ceramics},
volume = {20},
pages = {100678},
abstract = {In this work, waste fiberglass was up-cycled, alone, or mixed with used alumina-zirconia-silica (AZS) refractory from dismantled glass melting furnaces. Alkali activation was performed by suspending fiberglass and fiberglass/AZS powders in NaOH aqueous solution of various concentrations (8M, 6M, and 3M). The activation of waste fiberglass with 8M NaOH yields a gel with calcium and sodium-containing aluminosilicate hydrates. The addition of AZS refractory enabled the release of aluminates into the solution, which had beneficial effects on the mechanical properties. Low molarity activation yielded weaker materials which could be used as precursors for firing at moderate temperatures (800 °C and 1000 °C) to create cellular glass-ceramics, with a total porosity of up to 92 %. The firing of 8M activated samples resulted in glass ceramics with a 66–75 % porosity range and compressive strength of 10–23Mpa. The compressive strength-to-density ratio before and after firing was comparable to that of established commercial construction materials.},
keywords = {Materials for the environment},
pubstate = {published},
tppubtype = {article}
}
In this work, waste fiberglass was up-cycled, alone, or mixed with used alumina-zirconia-silica (AZS) refractory from dismantled glass melting furnaces. Alkali activation was performed by suspending fiberglass and fiberglass/AZS powders in NaOH aqueous solution of various concentrations (8M, 6M, and 3M). The activation of waste fiberglass with 8M NaOH yields a gel with calcium and sodium-containing aluminosilicate hydrates. The addition of AZS refractory enabled the release of aluminates into the solution, which had beneficial effects on the mechanical properties. Low molarity activation yielded weaker materials which could be used as precursors for firing at moderate temperatures (800 °C and 1000 °C) to create cellular glass-ceramics, with a total porosity of up to 92 %. The firing of 8M activated samples resulted in glass ceramics with a 66–75 % porosity range and compressive strength of 10–23Mpa. The compressive strength-to-density ratio before and after firing was comparable to that of established commercial construction materials.
S. Bhandari; P. Veteška; G. Vajpayee; M. Hinterstein; Ľ. Bača; Z. Hajdúchová; Z. Špitalský; G. Franchin; M. Janek
Material-extrusion based additive manufacturing of BaTiO3 ceramics: from filament production to sintered properties Journal Article
In: Additive Manufacturing, pp. 104238, 2024, ISSN: 2214-8604.
Abstract | Links | BibTeX | Tags: Additive Manufacturing
@article{BHANDARI2024104238,
title = {Material-extrusion based additive manufacturing of BaTiO3 ceramics: from filament production to sintered properties},
author = {S. Bhandari and P. Veteška and G. Vajpayee and M. Hinterstein and Ľ. Bača and Z. Hajdúchová and Z. Špitalský and G. Franchin and M. Janek},
url = {https://www.sciencedirect.com/science/article/pii/S2214860424002847},
doi = {https://doi.org/10.1016/j.addma.2024.104238},
issn = {2214-8604},
year = {2024},
date = {2024-01-01},
urldate = {2024-01-01},
journal = {Additive Manufacturing},
pages = {104238},
abstract = {Material extrusion (MEX) of thermoplastic filaments represents one of the most widely adopted additive manufacturing (AM) technologies. Unlike vat photopolymerization and powder-bed fusion methods that require high energy sources such as UV light and lasers, this fabrication method can be adapted for the fabrication of ceramics by using ceramic loaded filaments as feedstock, yet still employing relatively cheap equipment meant for polymeric materials with little adaptation of the process parameters; this potentially enables a broader diffusion of AM ceramic components. In this work, composite filaments with various weight fractions (60 – 80wt.%) of BaTiO3 were fabricated and characterized by electron microscopy, compressive mechanical testing, rheometry and thermogravimetric analysis to ensure a smooth and reliable printing process. After optimizing the printing parameters, the dense and porous printed samples were carefully debinded and sintered to obtain dense (~ 92%) and defect-free ceramic bodies. The sintered samples were characterized for phase development, microstructure, and pore size distribution. Careful observations reveal a particular range of pore size (0.1 – 5µm), which originates from the binder burn out process. The dielectric and ferroelectric properties of the fabricated samples were in good agreement with those reported in previous literature. This work provides a foundation for rapid prototyping of functional electro ceramics into reliable products with desired functional properties.},
keywords = {Additive Manufacturing},
pubstate = {published},
tppubtype = {article}
}
Material extrusion (MEX) of thermoplastic filaments represents one of the most widely adopted additive manufacturing (AM) technologies. Unlike vat photopolymerization and powder-bed fusion methods that require high energy sources such as UV light and lasers, this fabrication method can be adapted for the fabrication of ceramics by using ceramic loaded filaments as feedstock, yet still employing relatively cheap equipment meant for polymeric materials with little adaptation of the process parameters; this potentially enables a broader diffusion of AM ceramic components. In this work, composite filaments with various weight fractions (60 – 80wt.%) of BaTiO3 were fabricated and characterized by electron microscopy, compressive mechanical testing, rheometry and thermogravimetric analysis to ensure a smooth and reliable printing process. After optimizing the printing parameters, the dense and porous printed samples were carefully debinded and sintered to obtain dense (~ 92%) and defect-free ceramic bodies. The sintered samples were characterized for phase development, microstructure, and pore size distribution. Careful observations reveal a particular range of pore size (0.1 – 5µm), which originates from the binder burn out process. The dielectric and ferroelectric properties of the fabricated samples were in good agreement with those reported in previous literature. This work provides a foundation for rapid prototyping of functional electro ceramics into reliable products with desired functional properties.
K. Huang; A. De Marzi; G. Franchin; P. Colombo
UV-assisted Robotic Arm Freeforming of SiOC Ceramics from a Preceramic Polymer Journal Article
In: Additive Manufacturing, pp. 104051, 2024, ISSN: 2214-8604.
Abstract | Links | BibTeX | Tags: Additive Manufacturing, Polymer-derived ceramics
@article{HUANG2024104051,
title = {UV-assisted Robotic Arm Freeforming of SiOC Ceramics from a Preceramic Polymer},
author = {K. Huang and A. De Marzi and G. Franchin and P. Colombo},
url = {https://www.sciencedirect.com/science/article/pii/S2214860424000976},
doi = {https://doi.org/10.1016/j.addma.2024.104051},
issn = {2214-8604},
year = {2024},
date = {2024-01-01},
urldate = {2024-01-01},
journal = {Additive Manufacturing},
pages = {104051},
abstract = {Material extrusion is a very common and facile additive manufacturing technique for ceramic materials, allowing for rapid design and fabrication of 3D structures without expensive tools. However, fabricating sophisticated structures with large spanning parts and overhanging features using this technology is still a challenge. Here, UV-assisted additive manufacturing is enabled by performing material extrusion with the assistance of UV light using mixture of a preceramic polymer and a photopolymer. The rheological properties of the ink were investigated under UV light radiation to optimize the printing parameters to achieve excellent printability. Complex ceramic structures were fabricated with this method, such as spiral and truss structures, which would be very difficult to obtain using traditional material extrusion without sacrificial supports. These structures have potential application in lightweight ceramic components, such as sandwich structures.},
keywords = {Additive Manufacturing, Polymer-derived ceramics},
pubstate = {published},
tppubtype = {article}
}
Material extrusion is a very common and facile additive manufacturing technique for ceramic materials, allowing for rapid design and fabrication of 3D structures without expensive tools. However, fabricating sophisticated structures with large spanning parts and overhanging features using this technology is still a challenge. Here, UV-assisted additive manufacturing is enabled by performing material extrusion with the assistance of UV light using mixture of a preceramic polymer and a photopolymer. The rheological properties of the ink were investigated under UV light radiation to optimize the printing parameters to achieve excellent printability. Complex ceramic structures were fabricated with this method, such as spiral and truss structures, which would be very difficult to obtain using traditional material extrusion without sacrificial supports. These structures have potential application in lightweight ceramic components, such as sandwich structures.