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Materials Science in Additive Manufacturing Ceramic vat photopolymerization

VPP is based on the principle of selectively curing 2. VPP techniques suitable for ceramic
a photosensitive liquid resin contained in a shallow vat fabrication
through layer-by-layer photo-initiated crosslinking. An
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automated ultraviolet (UV) light source, guided by a 3D 2.1. Linear scanning SL
CAD model, is directed across the resin surface to cure it in a SL is regarded as the oldest rapid prototyping process and
precise, controlled manner. This process requires a support was invented by Hull in 1986. The process requires the
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structure during the build phase, which is lowered after creation of a 3D CAD model and its conversion to an STL
each layer is cured. The versatility and scalability of VPP file, which is sent to the build station control software. The
techniques make them particularly suitable for creating part is cut into a series of 2D slices of adequate thickness
complex features in various photosensitive polymers. and the model becomes ready to print. A support platform
While VPP is commonly associated with stereolithography is lowered into a vat of photocurable epoxy acrylate liquid
(SL) for rapid prototyping, its application in ceramic resin so that it rests below a surface of approximately equal
fabrication has also garnered considerable attention. to the desired thickness. In linear scanning SL, a UV laser
of nearly 100 milliwatts of power of fine beam diameter is
Ceramics, known for their high hardness, wear
resistance, corrosion resistance, and biocompatibility, have directed onto the resin using a series of computer-controlled
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mirrors. The laser causes the resin to polymerize and
been extensively applied in industries such as mechanical
engineering, electronics, and biomedical engineering. solidify it in a precise manner. Now, the platform is moved
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down with a single layer thickness to ensure that the new
Traditional ceramic manufacturing methods often involve level is recoated to the layer of liquid resin. The laser then
complex and time-consuming steps, such as casting, selectively solidifies the next layer and the overall process is
injection molding, and pressing, which can limit the repeated until the final object is built. Upon the completion
production of complex geometries. By offering a promising of the model, the platform is raised up and out of the resin
alternative, VPP enables the direct fabrication of ceramic to allow the unsolicited resin to drain away. Further, after
parts with intricate designs and high precision. This review removing from the machine any excess resin and support
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paper focuses on the various VPP technologies used for structure are removed and the part is cleaned using suitable
ceramic fabrication, their advantages, and applications. organic solvent to remove any uncured resin. The printed
The preparation of ceramic objects using VPP part is then cleaned using air and water to remove the
technologies typically involves the use of ceramic solvent and is then placed in a UV oven in order to cure
slurries, which are composed of ceramic particles, resins, and fully solidify it. Finally, the model can be sanded down
photoinitiators, dispersants, etc. These slurries should using ultra-fine sandpaper to obtain a smooth surface
maintain suitably large solid content and reduced viscosity finish. The SL technique is commonly used for creating
to ensure good printability and shape retention. The small-to-medium-sized concept models or prototypes for
addition of dispersants helps achieve a homogeneous aerodynamic testing in wind tunnels as well as parts with
dispersion of ceramic powder in the slurry, which is fine details such as those used in the preparation of scaffolds
beneficial to the printing process. However, incorporating for tissue engineering, optical, and microelectromechanical
ceramic particles into the slurry can pose several system (MEMS)/nanoelectromechanical system devices.
challenges, such as dispersion issues, viscosity problems, Materials used in SL are normally liquid resins with
sedimentation, and stability concerns. These challenges an appropriate proportion of photoinitiators. SL is not
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need to be addressed to optimize the printing process preferred to create chemically functionalized parts due to
and produce high-quality ceramic parts. In recent years, the fixed composition of the resins and may require post-
the development of pre-ceramic polymers has opened printing functionalization, if possible in some cases. It is
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up new possibilities for ceramic fabrication using VPP also possible to interchange containers filled with different
technologies. These polymers can be easily shaped and materials for multimaterial printing of single objects
formed and offer exceptional thermal stability, high through the SL process. For printing of ceramic parts using
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strength, and fracture toughness compared to traditional SL, ceramic slurries with resins or pre-ceramic precursors
ceramic powders. Using pre-ceramic polymers could are used to create green bodies, and further their processing
prevent many of the issues associated with ceramic slurries, at high temperatures are performed to obtain high-quality
such as drying problems, long processing times, and the ceramic parts. Light scattering is a challenging factor
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need for flammable solvents. This review also discusses influencing the printing quality for ceramic powder slurries,
the use of pre-ceramic polymers in VPP technologies, while the pre-ceramic precursors are best suited for printing
highlighting their advantages and potential applications in purposes. SL-printed parts are of high resolution due to a laser
the fabrication of advanced ceramic components. of fine diameter, which is scanned with high accuracy. The

Volume 4 Issue 3 (2025) 2 doi: 10.36922/MSAM025200031