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Materials Science in Additive Manufacturing Ceramic vat photopolymerization

suitable for SL can be synthesized by functionalizing compressive strength of 216 MPa while maintaining a
organosilicon compounds (siloxanes, silazanes, or low cellular density of 0.61 g/cm . This technique utilizes
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carbosilanes) with photopolymerizable groups including thiol-ene click chemistry to modify pre-ceramic polymers
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thiol, vinyl, acrylate, or methacrylate functionalities. The containing unsaturated bonds (e.g., polysiloxanes,
resin formulation incorporates polymerization inhibitors polycarbosilanes, and polycarbosilazanes). During
and UV-absorbing components to precisely control curing pyrolysis, the printed structures undergo controlled
depth and reduce light scattering, thereby enhancing conversion into dimensionally stable thermosets and
feature resolution. This monomer system can be further subsequently into dense glass ceramics with homogeneous
optimized through the strategic incorporation of metal shrinkage behavior, maintaining excellent shape retention.
alkoxides in controlled ratios, enabling the fabrication The process enables rapid production of pre-ceramic
of advanced composite ceramics. Researchers have components that yield defect-free, high-density ceramics
successfully extended this methodology to various pre- with superior surface quality after thermal treatment.
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ceramic polymers, developing efficient production routes Brodnik et al. demonstrated that pyrolysis behavior varies
for SiCN, silicon nitride, and silicon carbide ceramics significantly across different printed geometries, exhibiting
that combine dimensional accuracy with cost-effective structure-dependent shrinkage patterns and mechanical
manufacturing. 61,78-80 properties – contrasting with earlier assumptions of
uniform dimensional changes in pre-ceramic polymer
The DLP technique has also been used for printing conversion. Fabrication of SiCN ceramic microreactors
polymer-derived ceramic (PDC) structures with high from polysilazane has been demonstrated by Gyak et al.
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resolution and higher efficiency. They prepared dense for application in hydrogen generation with ammonia
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silicon oxycarbide 3D structures with no cracks and cracking. The researchers developed a novel pre-ceramic
high ceramic yield and micrometer resolution using processing method involving methacrylate-functionalized
engineered photosensitive methyl-silsesquioxane pre- polyvinylsilazane combined with a ternary photoinitiator
ceramic polymer. The printed structures were converted system {2,2-dimethoxy-2-phenylacetophenone,
into ceramics in a controlled pyrolysis process, which 2-hydroxy-2-methylpropiophenone, diphenyl(2,4,6-
involves heating to 1000°C for 60 min under nitrogen gas trimethylbenzoyl)-phosphine oxide in 3:1:1 ratio}
protection with a precisely maintained temperature ramp dissolved in toluene. This approach enables the fabrication
of 1°C/min. of advanced functional ceramics with exceptional
SiBCN ceramic components have been fabricated performance characteristics suitable for extreme
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with tuned polyborosilazane. A ceramic yield of 58% operating environments. Researchers have successfully
was obtained after pyrolysis at 1500°C while retaining the engineered composite ceramic materials by introducing
shape. The measured weight loss was found to be only functional additives into pre-ceramic systems. Schmidt
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0.35% after pyrolysis, and the highest hardness of 7.8 ± 0.3 et al. demonstrated this approach by dispersing alumina
GPa with a bulk density of 1.84 ± 0.01 g/cm was achieved. particles within a silicone-based pre-ceramic matrix,
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Furthermore, various printable pre-ceramic precursors have which upon pyrolysis transformed into porous mullite
been prepared by adding functional groups to the polymer ceramics with unique rhombicuboctahedral morphology.
backbones, mixing vinyl/allyl, and physically mixing The resulting 3D-printed mullite components exhibited a
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organosilicones of high ceramic yield with dispersant compressive strength of 1.8 ± 0.3 MPa, achieving a bulk
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diluents, monomer, etc. An approach different from the density of 3.1 g/cm while maintaining an exceptionally
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free radical polymerization has been proposed by Wang et high porosity level of 90% by volume.
al., which was introduced with thiol-ene click chemistry- Chen’s group from Shenzhen University has carried
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based SL method to produce ceramics upon thermal out research on the preparation of PDC precursor
treatment. The pre-ceramic precursor preparation involves photosensitive resins and their DLP 3D printing (Figure 7).
the mixing of polysiloxane and allylhydridopolycarbosilane A low-viscosity and high-curing-strength silicone-based
with phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide photosensitive resin co-doped with Zr/Ti was synthesized
(BAPOs) as photoinitiator. Sudan Orange G has been using the sol-gel method. Compact SiOC lattice structures
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used as a photo-absorber, whereas hydroquinone is a were obtained by pyrolysis at high temperatures in a
free radical scavenger. After homogenization, the pre- nitrogen environment. The evolution of phase composition
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ceramic mixture was functionalized with thiol groups and microstructure was characterized. Their results showed
using 1,6-hexanedithiol. The fabricated SiOC ceramic that the compressive strength of lattice structure ceramics
components achieved complete densification without was significantly improved as temperature augmented, and
detectable microporosity, demonstrating a remarkable the high concentration of metal doping further improved

Volume 4 Issue 3 (2025) 12 doi: 10.36922/MSAM025200031