Organically modified nanofillers, including nano SiO2, montmorillonite and attapulgite were loaded to stereolithography resin (SLR). The surface of nanofillers were modified using organic modifier of ...3-(trimethoxysilyl)propyl methacrylate (γ-MPS) and (1-hexadecyl)dimethyl allyl ammonium chloride (C16-DMAAC), and were characterized by FTIR and small angle XRD analysis. The morphology of nanocomposites were observed by TEM. Viscosity and curing speed of SLR nanocomposites at increasing nanofillers loading were also studied. The mechanical properties of printed samples fabricated by a home-made stereolithography apparatus (SLA) 3D printer were tested. The influence of nanoparticles on the accuracy was measured and discussed. It was found that addition of 5% w/w of nano SiO2 increased the tensile strength and modulus by 20.6% and 65.1% respectively, and the printed accuracy was not significantly influenced. This study opens the way to the application of nanocomposites in the desktop level SLA 3D printing.
For multi-ceramic materials based on the stereolithography (SL) principle, a 3D printing strategy was developed, and then an Al2O3-Si3N4 functionally graded material (FGM) ceramic part was fabricated ...using this strategy. Six groups of mixtures, with a Si3N4 content gradient of 20 vol% and a certain bimodal particle size distribution, were prepared using UV-curable pastes. A modified formula was proposed to evaluate the relationship between the actual minimum voidage of mixtures and the viscosities of their corresponding pastes. The viscosity of each paste was controlled using the prediction formula and optimization of dispersants. To design theprinting layer thickness, a mathematical relationship was established between Si3N4 content and curing depth of paste. The Al2O3-Si3N4 green body without deformation was printed using optimized parameters such as a layer thickness of 40 μm and a paste viscosity of ∼13,000 mPa·s. Finally, using debinding and sintering, denseparts having a complicated shape were obtained.
Stereolithography-based 3D printing is a promising method to produce complex shapes from piezoceramic materials. In this study, LCD-SLA 3D printing was used to create lead-free piezoceramics based on ...barium titanate (BaTiO3, BT). Three types of BT powders (micron, submicron and nanoscale) were tested in LCD-SLA 3D printing, and a technique for the preparation of a ceramic slurry suitable for LCD-SLA printing has been developed. Using TGA-DSC analysis, the thermal debinding parameters to obtain crack-free samples were determined, followed by further sintering and the study of the piezoelectric properties (εr = 1965, d33 = 200 pC/N, tan = 1,7 %). The results of the study demonstrate high potential for the production of complex piezoceramic elements that can be used in aviation, in particular, aviation radio equipment; in the marine industry for transceiver modules of hydroacoustic antennas; and in the nuclear industry for pressure control sensors in the steam–water path.
•3D printed samples with low GO concentration achieve high strength and ductility.•photopolymer resin did not suffer relevant structural changes due to dopant.•Optimum thermo-mechanical properties ...are correlated with the grade of structural order.
This research deals with adding graphene oxide, resulting in a novel resin suitable for additive manufacturing technologies based on layer-by-layer photopolymerization. The mechanical and thermal properties demonstrate that the specimens manufactured with graphene oxide with low concentration achieve an excellent combination of strength and ductility. Graphene oxide highly influences the molecular dynamics of the polymeric matrix, modulating the glass transition and thermal stability so that it obtains a more elastic behavior or enhanced stiffness, depending on the concentration. The structural properties show that the structural disorders in the polymer matrix are due to variations in graphene oxide content, so graphene oxide embedded in the photopolymer resin did not produce relevant structural changes, form any covalent bond, or add new functional groups.
The intricate structure of ceramic cores is crucial in producing high-temperature-resistant hollow blades. Traditional techniques for ceramic cores preparation, such as hot injection, rely heavily on ...moulds, thus limiting the production of complex structures in ceramic cores. Stereolithography 3D printing technology provides a novel approach to creating these cores, leveraging its precision and model customization capabilities. However, issues like the challenge of effectively controlling both porosity and strength hinder its widespread adoption. In this study, high-performance ceramic cores reinforced with in-situ YAG were successfully prepared by adding Y2O3 using stereolithography 3D printing technology. Thorough thermodynamic calculations for Y2O3 incorporation into Al2O3-based ceramic cores were systematically analysed, revealing the formation of Y3Al5O12 (YAG) at elevated temperatures due to Y2O3 and Al2O3 interaction. Subsequently, the variations in microstructure and properties were investigated across different temperatures. Due to diffusion, YAG sintered necks and cohesive framework were formed on the surface of Y2O3, resulting from the reaction between Y2O3 and Al2O3. YAG sintered necks and Y2O3 effectively inhibited crack deflection. The high degree of densification of the in-situ generated YAG and cohesive framework improved the mechanical properties; meanwhile, the presence of porosity between YAG and Al2O3 contributed to the enhancement of porosity. The cores exhibited exceptional mechanical properties at 1823.15 K. The open porosity was 30.08%. The flexural strengths were 41.2 MPa (298.15 K) and 32.0 MPa (1773.15 K). The design of YAG sintered necks by adjusting the sintering temperature introduced a new idea for synergistically adjusting porosity and strength. The advancement is anticipated to improve the production of intricately structured ceramic cores with superior performance.
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Stereolithography based additive manufacturing provides an effective method to fabricate complex-shaped SiC ceramic components. The dispersion and stability of the ceramic slurry are very important ...for stereolithography. In this study, the dispersion and stability of SiC ceramic slurries were investigated systematically. The effects of resin monomers, dispersants, particle size, solid loading and ball milling time on the dispersion, rheological behavior and stability of SiC ceramic slurries were studied in detail. Finally, an optimal SiC ceramic slurry for stereolithography based additive manufacturing was obtained, and complex-shaped SiC ceramic architectures were fabricated.
Additive manufacturing is a layer-by-layer strategy enabling the advanced design and fabrication of complex 3D objects and structures, overcoming geometry limitations and reducing waste production ...compared to conventional technologies. Among various additive manufacturing technologies, digital light processing (DLP), is an additive manufacturing technology used to print photopolymer parts, using a projected light source to cure an entire layer at once. Initially developed for pure resins, recent advances have demonstrated the potential of DLP in the polymerization of ceramic and metal-loaded suspensions, enabling the fabrication of ceramic and metal components after proper debinding and sintering. Such flexibility increases the potential of DLP for different applications, ranging from dental implants and bone scaffolds to smart biomaterials for soft robotics, smart wearables, and microfluidic devices. The review provides an overview of DLP technology and its recent advances; specifically, the review covers the photopolymer properties, the ceramic and metallic feedstock preparation, and the light-matter interaction mechanism underpinning the printing and post-processing steps. Finally, a description of the current application is provided and complemented with future perspectives.
In this paper, a ceramic suspension with appropriate viscosity was prepared by optimizing the powder solid content and the dispersant content. An Al2O3-ZrO2 ceramic green body was fabricated using ...the SLA technique, followed by the application of a liquid drying and two-step debinding process to prepare the defect-free Al2O3-ZrO2 ceramic green body. The relative density, phase composition, microstructure, grain size, and mechanical properties of Al2O3-ZrO2 samples sintered at different temperatures were compared. The main results indicated that the sample density increased with the sintering temperature until reaching a maximum density of 4.28 g/cm3 at 1600 °C. When the temperature further increased to 1650 °C, the density dropped instead. With increasing sintering temperature, both the number of grain boundaries and the number of pores located at the grain boundaries reduced greatly. The Vickers hardness of the samples first increased and reached its maximum at 1550 °C with a value of 17.6 GPa, and then decreased with further increases in sintering temperature. The fracture toughness increased with the sintering temperature and reached a maximum value of 5.2 MPa·m1/2 at 1650 °C. A sintering kinetics window which could offer the relationship between the sintering temperature and the relative density & grain size was set and also the microstructure evolution of the sintered body was conducted to get a deeper understanding of the 3D printing Al2O3-ZrO2 composites.
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•A defect-free Al2O3-ZrO2 composite was fabricated using SLA-based 3D printing.•Effects of sintering temperature on the properties of the sintered ceramics were examined.•Fracture toughness increased with T and had a maximum value of 5.2 MPa·m1/2 at 1650 °C.•Sample density increased with T and had a maximum density of 4.27 g/cm3 at 1600 °C.•Vickers hardness increased with T and had its maximum of 17.6 GPa at 1550 °C.
