TY - JOUR
T1 - Effects of plasma electrolytic oxidation process on the mechanical properties of additively manufactured porous biomaterials
AU - Gorgin Karaji, Zahra
AU - Hedayati, Reza
AU - Pouran, Behdad
AU - Apachitei, Julian
AU - Zadpoor, Amir A.
PY - 2017
Y1 - 2017
N2 - Metallic porous biomaterials are recently attracting more attention thanks to the additive manufacturing techniques which help produce more complex structures as compared to conventional techniques. On the other hand, bio-functional surfaces on metallic biomaterials such as titanium and its alloys are necessary to enhance the biological interactions with the host tissue. This study discusses the effect of plasma electrolytic oxidation (PEO), as a surface modification technique to produce bio-functional layers, on the mechanical properties of additively manufactured Ti6Al4V scaffolds based on the cubic unit cell. For this purpose, the PEO process with two different oxidation times was applied on scaffolds with four different values of relative density. The effects of the PEO process were studied by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), optical microscopy as well as static and dynamic (fatigue) mechanical testing under compression. SEM results indicated pore formation on the surface of the scaffolds after oxidation with a thickness of 4.85 ± 0.36 μm of the oxide layer after 2 min and 9.04 ± 2.27 μm after 5 min oxidation (based on optical images). The static test results showed the high effect of relative density of porous structure on its mechanical properties. However, oxidation did not influence most of the mechanical properties such as maximum stress, yield stress, plateau stress, and energy absorption, although its effect on the elastic modulus was considerable. Under fatigue loading, none of the scaffolds failed even after 106 loading cycles at 70% of their yield stress.
AB - Metallic porous biomaterials are recently attracting more attention thanks to the additive manufacturing techniques which help produce more complex structures as compared to conventional techniques. On the other hand, bio-functional surfaces on metallic biomaterials such as titanium and its alloys are necessary to enhance the biological interactions with the host tissue. This study discusses the effect of plasma electrolytic oxidation (PEO), as a surface modification technique to produce bio-functional layers, on the mechanical properties of additively manufactured Ti6Al4V scaffolds based on the cubic unit cell. For this purpose, the PEO process with two different oxidation times was applied on scaffolds with four different values of relative density. The effects of the PEO process were studied by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), optical microscopy as well as static and dynamic (fatigue) mechanical testing under compression. SEM results indicated pore formation on the surface of the scaffolds after oxidation with a thickness of 4.85 ± 0.36 μm of the oxide layer after 2 min and 9.04 ± 2.27 μm after 5 min oxidation (based on optical images). The static test results showed the high effect of relative density of porous structure on its mechanical properties. However, oxidation did not influence most of the mechanical properties such as maximum stress, yield stress, plateau stress, and energy absorption, although its effect on the elastic modulus was considerable. Under fatigue loading, none of the scaffolds failed even after 106 loading cycles at 70% of their yield stress.
KW - 3D printed scaffolds
KW - Additive manufacturing
KW - And mechanical properties
KW - Bio-functional surfaces
KW - Titanium alloys
UR - http://www.scopus.com/inward/record.url?scp=85015317620&partnerID=8YFLogxK
U2 - 10.1016/j.msec.2017.03.079
DO - 10.1016/j.msec.2017.03.079
M3 - Article
AN - SCOPUS:85015317620
SN - 0928-4931
VL - 76
SP - 406
EP - 416
JO - Materials Science and Engineering C: Materials for Biological Applications
JF - Materials Science and Engineering C: Materials for Biological Applications
ER -