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Materials Science in Additive Manufacturing Preparation and modification of porous Ti

the PVD method, the films prepared by the CVD method glycol (EG), water and ammonium fluoride, and conducted
have better matrix coverage and progressivity. anodic oxidation reactions using a direct current voltage
source. The voltages were set to 10, 15, 20, and 25 V and
4.2.3. Electrochemical modification continuously energized for 40 min. Observation of the

Electrochemical modification is one of the most widely used surface of porous screws reveals that the morphology
methods for material surface modification. The underlying of the anodized surface is influenced by the location of
principle involves preparing a metal salt solution with pre- the screw and the magnitude of the voltage. Shokuhfar
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added substances, using the material to be plated as the et al. used HH F and ethylene glycol as electrolytes, 60 V
4
electrode, and leveraging an electrochemical reaction to constant voltage, and direct current to conduct anodic
precipitate ions in the solution and fix them on the material’s oxidation experiments on CP-Ti surface and TC4 surface,
surface to generate a coating. According to the reaction respectively, to obtain periodic nanotube structures. The
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principle, it is mainly divided into electrochemical deposition, total cell density was higher on the cp-Ti surface than on
micro-arc oxidation, anodic oxidation, and other processes. the TC4 alloy surface because the precipitation of Al and V
elements in the TC4 alloy affected cell proliferation.
Electrochemical deposition, also known as
electrodeposition, electrophoretic deposition, or During micro-arc oxidation, the material is used as the
electroplating, is a method of depositing materials (metals, anode in the electrolyte, and a strong voltage is employed
polymers, ceramics, glass, and their composites) onto a base to generate micro-arc discharge and local high temperature
material through redox reactions using an electric current. so that the electrolyte ions vaporize at high temperature
Vidal et al. performed pulse electrodeposition on porous to form plasma and oxidize with the porous implant,
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titanium scaffolders to achieve uniform coverage of Ca-P thus generating a metal oxide coating with TiO as the
2
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coating. The results of antibacterial tests showed that the main component, as shown in Figure 12B. The coating
scaffolds possess antibacterial activity against Gram-positive prepared by this process is mainly affected by factors such
and Gram-negative bacterial strains and effectively reduced as pulse frequency, duty cycle, duration, and electrolyte
the infection around the implant. In addition, researchers composition. 113
also electroplated Cu, Zn, Ag, and other metals onto the Carbonate, sulfate, and silicate solutions containing
material’s surface to improve biocompatibility. Guo et al. Ca/P/Si elements are the most commonly used
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prepared titanium copper/titanium copper nitride coating electrolytes. Yan et al. formed a bioactive coating
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by electroplating on the surface of the titanium scaffold. enriched with micropores on the pore wall of porous
Biological experiments showed that the proliferation titanium by micro-arc oxidation. The composition analysis
and adhesion of human bone mesenchymal stem cells of the coating shows that the porous titanium coating is
on coated scaffolds were higher than those on blank mainly composed of anatase and rutile TiO and other
2
scaffolds. The coating plays a significant role in adsorbing complex Ca-P-Sr phases. In vitro, osteogenic induction
hBMSCs, upregulating SDF-1a/CXCR4 gene expression, experiments showed that the porous titanium treated with
and stimulating extracellular signal-related kinase (Erk) MAO displayed good apatite induction ability. In addition
and Akt signaling pathways. Compared with conventional to the traditional electrolyte, some new materials, such
chemical deposition, the coating materials prepared by as graphene, are also added to the solution. Sun et al.
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electrochemical deposition have better uniformity, wider coated graphene on a porous titanium alloy using a micro-
thickness range, and higher bonding strength. arc oxidation process. Biological experiments showed
The anodizing method can form a uniform porous that graphene coating significantly improved the surface
structure on the surface of materials, which is a convenient roughness of the material, and promoted the adhesion,
and fast method for preparing highly ordered nanotube growth, and proliferation of human adipose-derived
stem cells. In addition, graphene-coated scaffolds also
structures, as shown in Figure 12A. The geometric successfully repaired rabbit mandibular defects, providing
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characteristics of nanotube arrays (morphology, length, a new idea for the clinical application of tissue engineering
pore size, and wall thickness) are influenced by various in the field of oral and maxillofacial bone defect repair. The
factors such as anodizing time, voltage, electrolyte coating prepared by micro-arc oxidation has the advantages
composition, viscosity coefficient of electrolyte, and of good wear resistance, strong corrosion resistance, and
substrate composition. Its electrolytes are mainly small thermal conductivity. Applying different electrolyte
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composed of nitric acid, hydrofluoric acid, and organic components can ensure the other functions achievable
compounds such as fluoride salts and ethylene glycol. 110 by micro-arc oxidation coating, a property that can be
Liang et al. utilized titanium alloy porous screws as leveraged to add relevant substances to the electrolyte to
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anodes, using an electrolyte solution containing ethylene make the coating more biocompatible.

Volume 3 Issue 1 (2024) 15 https://doi.org/10.36922/msam.2753