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RESEARCH ARTICLE

A continuous net-like eutectic structure enhances the

corrosion resistance of Mg alloys

Cijun Shuai 1,2,3 , Wenjing Yang , Youwen Yang , Chengde Gao , Chongxian He *, Hao Pan *
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1 State Key Laboratory of High Performance Complex Manufacturing, College of Mechanical and Electrical Engineering,
Central South University, Changsha 410083, People’s Republic of China
2 Jiangxi University of Science and Technology, Ganzhou 341000, People’s Republic of China
3 Shenzhen Institute of Information Technology, Shenzhen 518172, People’s Republic of China
4 Department of Periodontics and Oral Mucosal Section, Xiangya Stomatological Hospital, Central South University,
Changsha 410078, People’s Republic of China

Abstract: Mg alloys degrade rather rapidly in a physiological environment, although they have good biocompatibility and
favorable mechanical properties. In this study, Ti was introduced into AZ61 alloy fabricated by selective laser melting,
aiming to improve the corrosion resistance. Results indicated that Ti promoted the formation of Al-enriched eutectic α phase
and reduced the formation of β-Mg Al phase. With Ti content reaching to 0.5 wt.%, the Al-enriched eutectic α phase
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constructed a continuous net-like structure along the grain boundaries, which could act as a barrier to prevent the Mg matrix
from corrosion progression. On the other hand, the Al-enriched eutectic α phase was less cathodic than β-Mg Al phase in
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AZ61, thus alleviating the corrosion progress due to the decreased potential difference. As a consequence, the degradation
rate dramatically decreased from 0.74 to 0.24 mg·cm ·d . Meanwhile, the compressive strength and microhardness were
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increased by 59.4% and 15.6%, respectively. Moreover, the Ti-contained AZ61 alloy exhibited improved cytocompatibility.
It was suggested that Ti-contained AZ61 alloy was a promising material for bone implants application.
Keywords: eutectic α phase; net-like structure; selective laser melting; mg alloys; corrosion resistance

*Correspondence to: Dr. Chongxian He, Jiangxi University of Science and Technology, Ganzhou 341000, People’s Republic of China;
Tel: +86-731-84805412; Fax: +86-731-88879044; hechongxian@csu.edu.cn. Hao Pan, Department of Periodontics and Oral Mucosal Section,
Xiangya Stomatological Hospital, Central South University, Changsha 410078, People’s Republic of China; panhao@csu.edu.cn

Received: May 5, 2019; Accepted: June 4, 2019; Published Online: July 1, 2019
Citation: Shuai C J, Yang W J, Yang Y W, et al., 2019, A continuous net-like eutectic structure enhances the corrosion
resistance of Mg alloys. Int J Bioprint, 5(2): 207. http://dx.doi.org/10.18063/ijb.v5i2.207

1. Introduction could be tolerable. Wen et al. investigated the corrosion
[10]
Mg alloys are potential bone implants in the orthopedic behavior of Mg-Al series alloys and claimed that their
field due to their good biocompatibility, natural corrosion resistances were closely related to Al content.
biodegradability, and similar density and Young’s modulus Nevertheless, Mg-Al series alloys degrade rather rapidly
to nature bone [1-5] . Compared with other Mg alloys, in physical environments, because the high potential
Mg-Al series alloys exhibit more favorable mechanical differences between α-Mg grains and β phase cause severe
strength with the help of Al solid solution strengthening galvanic corrosion [9,10] . The rapid degradation results in a
and precipitation strengthening, thus attracting intensive fast loss of mechanical strength, as well as a large amount
researches in recent years [6-8] . Witte et al. investigated of hydrogen accumulation and local alkalization, which
[9]
the degradation behavior and the bone response of Mg-Al significantly limits their clinical applications.
series alloys, including AZ31 and AZ91. They reported A workable strategy to improve the corrosion
that a small amount of Al released during the degradation resistance is to change the component of the second

A continuous net-like eutectic structure enhances the corrosion resistance of Mg alloys © 2019 Shuai, et al. This is an Open Access article distributed under
the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (http://creativecommons.org/licenses/by-nc/4.0/), permitting all
non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
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