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Engineering Science in
Additive Manufacturing Machine learning for biomedical metal AM

used in implant manufacturing for orthopedics, dentistry, a vacuum environment, and preheating the powder bed
and cardiovascular applications due to their superior before melting. This approach helps reduce residual stresses
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mechanical properties, biocompatibility, and corrosion and control microstructure. 14,15 EB-PBF technology excels
resistance. With the significant trend of global population in manufacturing titanium alloy implants with simulated
aging and the widespread increase in health awareness, the bone stiffness characteristics, effectively mitigating the
market demand for biomedical materials (such as those stress shielding effect. 16
used in joint replacement, dental restoration, and trauma DED, as one of the most mature industrial AM
treatment) has experienced explosive growth. Ideal technologies, fundamentally involves the controlled
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biomedical metals require personalized geometric shapes deposition of metal powder. The DED technique
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that precisely match the patient’s individual anatomy. In includes laser powder DED and laser wire DED and
addition, to promote osseointegration and avoid the stress electron beam DED. DED technique offers advantages
shielding effect, the internal structure is typically designed
as porous and possesses mechanical properties matching such as high printing speeds, the ability to process large-
those of natural bone tissue. However, traditional scale components, compatibility with various metals
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manufacturing processes such as forging and casting and alloys, and the capability to manufacture parts from
suffer from inherent limitations including extremely low heterogeneous materials. Components produced by this
material utilization, difficulty in precisely controlling technology exhibit fine, uniform microstructures due to
internal pore structures, and inability to achieve rapid melting and solidification under high-energy lasers,
personalized customization, severely restricting their resulting in excellent mechanical properties and near-
clinical application. In contrast, additive manufacturing complete density. It is also suitable for complex surface
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(AM), an advanced layer-by-layer fabrication technology, deposition and part repair.
leverages its digital and high-freedom manufacturing Research data further confirm that biomedical metal
characteristics to precisely form personalized biomedical AM significantly surpasses traditional processes in key
metals that closely match patient anatomy. It can also performance metrics (Table 1). Attar et al. demonstrated
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construct biomimetic bone scaffolds with complex porous that commercially pure titanium components produced
structures, effectively promoting bone tissue ingrowth, through LB-PBF exhibit markedly higher microhardness,
enhancing osseointegration, and significantly reducing compressive strength, and tensile strength than
stress shielding risks. 10 conventionally fabricated samples, achieving near-full-
density microstructures and outstanding comprehensive
1.1. Introduction to AM technologies for biomedical mechanical properties. Regarding corrosion resistance,
metals
Zhao et al. noted that Ti-6Al-4V alloy components
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In the field of medical metal AM, multiple mainstream manufactured through LB-PBF demonstrated
technologies are applicable to different clinical scenarios outstanding corrosion resistance in tests simulating
due to their unique process characteristics. The most in vivo environments, exhibiting corrosion rates
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widely applied techniques currently include laser beam significantly lower than industry standards. Similarly, Bai
powder bed fusion (LB-PBF), electron beam powder bed et al. found that Ti-6Al-4V alloy formed using EB-PBF
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fusion (EB-PBF), and directed energy deposition (DED) technology exhibited superior corrosion resistance in
(Figure 1). phosphate-buffered solution compared to conventional
LB-PBF employs a high-energy laser beam to forged components. This compelling experimental
selectively melt layers of metal powder, achieving layer- evidence demonstrates that AM not only overcomes
by-layer manufacturing through rapid solidification. the limitations of traditional processes in producing
This technology is renowned for its exceptional forming personalized and complex structures but also achieves
precision and capability to produce complex structures, substantial breakthroughs in material density, mechanical
enabling the fabrication of components with high density, properties, and service reliability. This establishes a robust
fine grain structure, and uniform microstructure. technological foundation for developing a new generation
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Research indicates that commercially pure titanium and of high-performance, customized medical metals. 21
Ti-6Al-4V alloy components formed through LB-PBF These technologies are employed to process various
exhibit significantly superior microhardness, compressive biomedical metals; however, each category presents distinct
strength, and tensile strength compared to those produced application advantages and manufacturing challenges.
by conventional processes. 13 Biomedical metals serve as core materials for implants in
EB-PBF differs from LB-PBF by utilizing a high-energy orthopedics, dentistry, and cardiovascular applications.
electron beam as the heat source, typically operating in They can be classified into several major categories: 1

Volume 1 Issue 4 (2025) 2 doi: 10.36922/ESAM025440031