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Materials Science in Additive Manufacturing High-performance materials in AM

costs, and more outstanding capabilities than traditional 2. Additive manufacturing techniques
manufacturing processes.
2.1. Binder jetting
According to the ISO/ASTM52900-21 standard ,
[4]
AM techniques are classified into seven categories, as Binder jetting additive manufacturing (BJT) is an
shown in Figure 1, namely, binder jetting (BJT), directed inexpensive AM technique that uses liquid adhesives to
energy deposition (DED), material extrusion (MEX), bond and cures specific parts of a powdered material layer
material jetting (MJT), powder bed fusion (PBF), sheet by layer into the green state, followed by different types of
lamination (SHL), and vat photopolymerization (VPP). post-processing to obtain a finished product, depending
The technical characteristics, application scenarios and on the nature of the material [5,6] .
applicable material types vary among these techniques. The BJT technology is an AM process conducted entirely
Given that, these techniques have developed in different at room temperature. As there is no deformation due to
aspects in recent years, culminating in the current status. thermal effects, it can be used to build large parts and there
The current summary and overview of these seven is no need to design additional support structures when
technologies is relatively rare, which is unparalleled to the using BJT technology. In some cases, it is even possible to
rapid development of the industry. fabricate colored products. This technology is now used to
On the basis of continuous technological advances, print finished parts with complex internal structures and
the adaptability of high-performance raw materials is geometries in a variety of materials including metals [5,6] ,
another key issue, and even, empowering and trying ceramics , and polymers .
[7]
[8]
to further explore the potential of materials through The major disadvantage of BJT as compared to
AM technology will be the focus of attention of the several other AM technology is that it is uncompetitive
application end of AM field in the future. This review
focuses on two core classes of materials, namely in many commercial cases due to shrinkage problems
polymers and metals, and highlights a representative when machining metals and the difficulty of achieving
[9]
high-performance material from each of them. The fully dense parts directly . Furthermore, the fabricated
review also focus on those materials that have a fit products are very fragile in their green state before post-
with AM technology in terms of application areas processing, limiting the use of the AM process to a certain
and have already demonstrated significant research extent. Figure 2 clearly reflects several typical product
[10]
value in conventional processing to explore their defects when using BJT techniques .
latest developments in the AM field as well as further Improvements and refinements to address this feature
possibilities for the future. Engineering plastics such as are ongoing. One of the main treatments is the use of
polyimide and polyetheretherketone (PEEK), as well as additives to provide additional treatment to the green
alloys such as high entropy alloys (HEAs), are among parts before sintering. This process modifies the internal
the star materials that fit this profile. We believe that structure of the green parts, increasing the number of
tracking the development of these high-performance particle alignments and the size of inter-particle contacts
materials in the AM field will help us further understand to make it denser and more stable . This approach
[11]
the growth trajectory of AM technology. has been demonstrated with several different types of
[12]
[13]
Therefore, the final section of the review includes additives, including metal salts , metal-organic inks ,
[14]
the relevant, up-to-date standards in the AM field. This and sol-gel .
multidimensional summary is intended to provide another Building on this foundation, related research to gain
perspective on the development of the technology. insight into the effects of reactive binders on the creep
and densification mechanisms of binder-jet 3D printed
parts has also been conducted recently. Grant et al.
investigated the intrinsic mechanism of aqueous titanium
bis-ammonium lactato dihydroxide (TALH) as a binder
to alter the creep of the samples and achieved significant
deformation improvement .
[11]
2.2. Directed energy deposition
DED technology melts metal powders or wires during
the manufacturing process and deposits them layer by
Figure 1. Seven different categories of AM techniques . layer onto specified areas and cooled them to form the
[4]

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