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Materials Science in Additive Manufacturing High-performance materials in AM

this technology build complex 3D structures by spraying a
photosensitive liquid material layer by layer over a specified
area with a nozzle and curing it with ultraviolet light.
This technology offers high cost-efficiency and
application potential. In addition to being suitable for
traditional thermoset photopolymers, MJT has shown
adaptability to a variety of materials such as gels and bio-
based materials . It has also received increasing interest
[30]
from the market as well as industry in recent years because
Figure 4. Illustration of material extrusion with or without cells it can be used in informal settings such as office scenarios
(permission obtained from authors) . due to its similar working characteristics to traditional
[25]
printers . On the other hand, the ability to print
[29]
One of the advantages of MEX technology is that it is simultaneously with multiple materials is a major advantage
inherently less restrictive in terms of raw materials. Most of MJT technology. The high dimensional accuracy and
of the feedstocks are very inexpensive, and a considerable low surface roughness of the finished products fabricated
proportion of the model material is open source, reducing using MJT technology make it potentially useful in areas
the cost of learning for the user themselves, and making such as cutting-edge customized medicine, aerospace, and
it highly adaptable and relevant for the home market. other applications .
[31]
At the same time, 3D printers using MEX technology The current shortcomings of MJT technology
are generally less expensive to maintain and run and are are divided into two principal areas: material and
therefore used in some commercial scenarios to produce technology. The layer-by-layer method has gaps and
prototypes.
defects that can have a significant impact on the final
On the other hand, there are limitations to the strength performance of certain elastomeric materials, such as
of the finished products printed by MEX technology, fatigue life [32] ; on the other hand, the raw materials used
especially for the perpendicular Z-axis direction (along the in MJT technology are photosensitive, the mechanical
build direction), where there is a large deficit in strength. properties of the finished product could potentially
At the same time, if the user tries to increase the accuracy deteriorate over time [33] .
of a 3D printer using MEX technology, the corresponding Targeted research has been followed up. By studying the
fabrication time increases, which limits the value of this aging of different color resins printed by MJT over time,
technology to a certain extent.
the researchers found that the stiffness of the material
Most importantly, the thermoplastic material in a MEX first increased and then decreased over time, and the
process can be heated to a maximum of 500°C, thereby aging process has a potential relationship with the color
emitting harmful gases and ultrafine particles that can lead and appearance of the product itself . At the same time,
[34]
to a reduction in indoor air quality in domestic scenarios. various tests were carried out; the structure of the whole
This poses a potential health problem for the occupants of experiment is shown in Figure 5.
the house, considering that some components take more These studies provided the basis for understanding the
than a few hours to fabricate .
[27]
long-term factors affecting the changes in the appearance
It is worth noting that MEX technology may be and performance of objects printed using MJT technology.
developed for medical applications because it is compatible In the future, on this basis, through a series of research on
with most materials. This certainly broadens the potential the parameters of the entire industry chain and product
market for this easy-to-use technology. Recent studies design, it may be possible to greatly increase the lifespan
have successfully used medical-grade polyamide (PA)12 of the product and enhance the actual application value of
polymer as matrix material to complete the print; it was the technology.
also found that by adding silver nitrate, polyethylene
glycol or polyvinylpyrrolidone, the printed samples could 2.5. Powder bed fusion
further exhibit higher tensile strength or sterilization Powder bed fusion (PBF) technology is an important
properties . branch of AM. Especially in the field of metal additive
[28]
manufacturing, PBF occupies an absolute advantageous
2.4. Material jetting position. Figure 6 illustrates the market share held
MJT technology is an AM technology that is somewhat by different technologies in the metal additive
similar to conventional 2D printers . 3D printers using manufacturing segment in 2019 [17] . PBF technology, as
[29]

Volume 2 Issue 3 (2023) 4 https://doi.org/10.36922/msam.1587