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PERSPECTIVE ARTICLE

Perspectives on Additive Manufacturing Enabled Beta-

Titanium Alloys for Biomedical Applications

Swee Leong Sing *
1,2
1 Department of Mechanical Engineering, National University of Singapore, Singapore
2 Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering, Nanyang Technological University,
Singapore

Abstract: “Stress shielding” caused by the mismatch of modulus between the implant and natural bones, is one of the major
problems faced by current commercially used biomedical materials. Beta-titanium (β-Ti) alloys are a class of materials that have
received increased interest in the biomedical field due to their relatively low elastic modulus and excellent biocompatibility.
Due to their lower modulus, β-Ti alloys have the potential to reduce “stress shielding.” Powder bed fusion (PBF), a category
of additive manufacturing, or more commonly known as 3D printing techniques, has been used to process β-Ti alloys. In this
perspective article, the emerging research of PBF of β-Ti alloys is covered. The potential and limitations of using PBF for
these materials in biomedical applications are also elucidated with focus on the perspectives from processes, materials, and
designs. Finally, future trends and potential research topics are highlighted.
Keywords: Additive manufacturing; 3D printing; Powder bed fusion; Selective laser melting; Electron beam melting; Titanium

*Correspondence to: Swee Leong Sing, Department of Mechanical Engineering, National University of Singapore, Singapore; sweeleong.sing@nus.edu.sg
Received: December 3, 2021; Accepted: December 21, 2021; Published Online: January 12, 2022

(This article belongs to the Special Section: 3D Printing and Bioprinting for the Future of Healthcare)
Citation: Sing S L. 2022, Perspectives on Additive Manufacturing Enabled Beta-Titanium Alloys for Biomedical Applications. Int J Bioprint,
8(1):478. http:// doi.org/10.18063/ijb.v8i1.478

1. Introduction first input with process parameters and then sliced into
two-dimensional cross sections. The PBF process itself
Powder bed fusion (PBF) is a group of additive involves a cycle of depositing powder layers onto the build
manufacturing (AM) or three-dimensional (3D) printing platform or previously processed layers, then the melting
techniques. When equipped with lasers as energy sources, of the powder selectively using laser or electron beam.
the processes are also known as laser powder bed fusion The areas that are melted follow the cross sections from
(L-PBF). L-PBF is also commercially known as selective the sliced CAD data file. After this step, the build platform
laser melting (SLM) or direct metal laser melting [1,2] . is then lowered and a new powder layer is deposited. The
Another type of PBF process uses electron beam as the cycle repeats until the full 3D components are fabricated .
[6]
energy source and thus is known as electron beam powder As a result of the cyclic process and repeated thermal
bed fusion (EB-PBF) or commercially as selective cycles, the materials undergo solid-liquid-solid phase
electron beam melting. These manufacturing processes transformations . These unique physical phenomena
[7]
have shown successes in processing alloys and even bring about the microstructural changes which affect the
[3]
ceramics [4,5] . Like any other AM techniques, PBF has mechanical properties of the materials. The detailed PBF
the capability to fabricate functional parts with complex process is also described elsewhere [8-11] . A schematic of the
geometry due to its freeform fabrication capabilities. PBF process is shown in Figure 1.
The process starts from designing of the parts using a Most of the current materials used for biomedical
computer-aided design (CAD) software and exporting the implants commercially, such as 316L stainless steel,
data files into the PBF equipment. The data files are also CoCrMo, and even Ti6Al4V, have a problem which is the

© 2022 Author(s). This is an Open Access article distributed under the terms of the Creative Commons Attribution License, permitting distribution and
reproduction in any medium, provided the original work is properly cited.
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