Surface modification of Ti-6Al-4V alloys manufactured by selective laser melting: Microstructural and tribo-mechanical characterization

The human body is an extremely aggressive environment in terms of corrosion. Titanium and its alloys are one of the most popular biomaterials used for implant applications due to biocompatibility. However, every element introduced into the body is treated as a foreign body. The human body’s immune response may, therefore, lead to implant rejection and the need for reoperation. For this purpose, it seems important to carry out surface modifications by applying coatings and inter alia by texturing to implants. The objective of this paper is to investigate the effect of surface treatment on the chosen properties of the pure titanium (Grade II) samples obtained by selective laser melting (SLM) processing. The samples were divided into five groups: Initial state (after polishing), after surface modification by the physical vapour deposition (PVD) method—CrN and TiN coatings were deposited on the surface of the tested material, and after laser texturing. The paper presents the results of the microscopic investigation, chemical and phase compositions, and physicochemical and electrochemical properties of the tested samples. Based on the results obtained it can be concluded that the hybrid surface modification shows significant effects on the properties of the pure titanium. The samples with the textured PVD-deposited TiN coatings were characterized by favorable physicochemical properties and were the highest performing in terms of pitting corrosion resistance.

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Corrosion Resistance and Mechanical Characterization of Ankle Prostheses Fabricated via Selective Laser Melting

Procedia CIRP ◽

10.1016/j.procir.2017.04.037 ◽

2017 ◽

Vol 65 ◽

pp. 25-31 ◽

Cited By ~ 3

Author(s):

Erica Liverani ◽

Andrea Balbo ◽

Cecilia Monticelli ◽

Alberto Leardini ◽

Claudio Belvedere ◽

...

Keyword(s):

Corrosion Resistance ◽

Selective Laser Melting ◽

Mechanical Characterization ◽

Laser Melting

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Microstructural and Mechanical Characterization of Thin-Walled Tube Manufactured with Selective Laser Melting for Stent Application

Journal of Materials Engineering and Performance ◽

10.1007/s11665-020-05366-9 ◽

2021 ◽

Author(s):

E. Langi ◽

L. G. Zhao ◽

P. Jamshidi ◽

M. M. Attallah ◽

V. V. Silberschmidt ◽

...

Keyword(s):

Stainless Steel ◽

Selective Laser Melting ◽

316L Stainless Steel ◽

Mechanical Characterization ◽

Patient Specific ◽

Laser Melting ◽

Stress Strain ◽

Thin Walled Tube ◽

Thin Walled

AbstractThis paper focuses on microstructural and mechanical characterization of metallic thin-walled tube produced with additive manufacturing (AM), as a promising alternative technique for the manufacturing of tubes as a feedstock for stents micromachining. Tubes, with a wall thickness of 500 μm, were made of 316L stainless steel using selective laser melting. Its surface roughness, constituting phases, underlying microstructures and chemical composition were analyzed. The dependence of hardness and elastic modulus on the crystallographic orientation were investigated using electron backscatter diffraction and nanoindentation. Spherical nanoindentation was performed to extract the indentation stress–strain curve from the load–displacement data. The obtained results were compared with those for a commercial 316L stainless steel stent. Both tube and commercial stent samples were fully austenitic, and the as-fabricated surface finish for the tube was much rougher than the stent. Microstructural characterization revealed that the tube had a columnar and coarse grain microstructure, compared to equiaxed grains in the commercial stent. Berkovich nanoindentation suggested an effect for the grain orientation on the hardness and Young’s modulus. The stress–strain curves and the indentation yield strength for the tube and stent were similar. The work is an important step toward AM of patient-specific stents.

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