Page 10 - IJAMD-2-2

International Journal of AI for
Materials and Design AI-driven material development for AM

2.2. Material jetting (MJT) and complex thermal histories have a critical influence

MJT operates similarly to inkjet printing, where liquid on grain structure, dislocation evolution, and phase
materials are deposited as microdroplets through a print transformation behavior. To overcome these limitations,
head and cured by ultraviolet light to build a structure. advancements in AM-specific material development are
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essential to optimize phase stability, enhance mechanical
The process utilizes two types of materials: Build material, properties, and, in particular, ensure reproducibility.
which forms the final part, and support material, which
provides structural integrity during printing and is later 2.5. Material extrusion
removed through dissolution. MJT technology has the
advantages of high resolution, multi-material printing In MEX, a material is first heated to its melting point,
then extruded as a filament, and finally deposited to
capability, and the ability to fabricate intricate geometries, form a structure. Two common MEX methods include
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surpassing material extrusion (MEX), binder jetting (BJT), fused deposition modeling (FDM) and direct ink writing
and powder bed fusion (PBF) in surface accuracy. It (DIW). FDM relies on thermoplastic filaments that are
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is widely applied in aerospace, biomedical, dental, and melted and extruded, making it widely used for rapid
mechanical engineering. 16 prototyping, educational applications, and engineering
2.3. BJT part fabrication due to its low cost, ease of handling, and
ability to print with multiple materials. In contrast, DIW
BJT constructs 3D structures by selectively depositing a involves extruding high-viscosity inks, pastes, or gels,
liquid binder onto a powder bed, gradually bonding the enabling the fabrication of soft materials, ceramics, and
material to form the desired shape. Unlike other AM bioprinted structures. Due to its low cost, ease of handling,
methods, BJT does not require a heat source, such as a and capability for multi-material printing, MEX is well-
laser or electron beam, making it a more cost-effective suited for rapid prototyping, educational applications,
approach. BJT-printed parts are self-supporting, and engineering part fabrication. However, its relatively
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eliminating the need for support structures and enabling low resolution limits its suitability for small-scale or
the simultaneous fabrication of multiple components. highly detailed components. At present, the MEX process
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However, the printed parts often exhibit lower mechanical is widely used in medical modeling, engineering parts,
strength, necessitating post-processing treatments, such as prototyping, tissue engineering, and bioprinting devices. 24
sintering or infiltration, to improve material performance.
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BJT is widely applied in biomedical engineering, mold 2.6. Directed energy deposition (DED)
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casting, and food technology. 20 DED melts and deposits materials simultaneously using a
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2.4. PBF high-energy heat source, such as a laser beam or arc. The
process utilizes powder or wire as feedstock, with material
PBF is a widely adopted AM process, primarily used for introduced into a molten pool during printing. Multi-axis
metals and polymers, with limited applications in motion control enables complex geometries, making DED
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ceramics and composites. It has several different terms, suitable for metallic multi-materials, functional gradient
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including selective laser sintering, electron beam melting, materials, composite fabrication, and component repair.
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selective laser melting, and direct metal laser sintering. Notably, DED is primarily used for metallic materials
PBF utilizes a powder bed, where the material is selectively and offers a significantly higher deposition rate than PBF,
fused using a laser or electron beam, with layer deposition making it favorable for large-format component fabrication.
and fusion repeating until the final structure is formed. Despite its versatility, DED material design remains
An inert gas-protective environment is often needed to complex because the rapid solidification leads to non-
prevent oxidation.
equilibrium microstructures, affecting phase stability,
Despite its widespread use, materials used for PBF still residual stress, and mechanical performance. Similar to
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primarily derive from commercially available materials, PBF, most alloys used in DED are legacy alloys originally
which were not originally designed for AM, leading designed for conventional manufacturing methods, limiting
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to several key challenges. Many existing commercial the full exploration of DED’s potential. This underscores the
alloys (e.g., 7075Al alloy, H13 tool steel, Inconel718 critical need for developing AM-specific materials to fully
nickel-based superalloy, and CoCrFeMnNi Cantor leverage the capabilities of these AM techniques.
high-entropy alloy) are prone to hot cracking and defect
formation, compromising part integrity and limiting 2.7. Sheet lamination (SHL)
their applicability. In addition, controlling microstructure SHL constructs 3D parts by stacking and bonding
evolution remains a critical issue, as rapid solidification material layers, which are cut using laser or mechanical

Volume 2 Issue 2 (2025) 4 doi: 10.36922/IJAMD025100007