Laser additive manufacturing of Mg-based composite with improved degradation behaviour

ABSTRACT

Magnesium (Mg) alloy shows great potential as bone implant owing to its favourable biocompatibility and degradability. In the present work, bioglass-reinforced Mg-based composite was manufactured via laser additive manufacturing. The results showed that too low a volumetric energy density (E_v) resulted in the appearance of open pores on the surface, which significantly deteriorated the densification behaviour. In contrast, too high an E_v caused the occurrence of the‘balling phenomenon’ with discontinuous surface, because of the excessive liquid formation and extended pool lifetime. Under a proper E_v of 185.19 J/mm³, favourable part with high densification rate was obtained. Meanwhile, the refined grains together with orderly dispersed reinforcing particles contributed to the enhanced mechanical properties. Significantly, the incorporated bioglass promoted the apatite deposition on Mg matrix, which served as an effective protection layer and reduced the degradation rate. Furthermore, it also improved the cell growth and differentiation, showing great potential in clinical bone repair.

KEYWORDS:

• Laser additive manufacturing
• Mg alloy
• bone implant
• forming quality
• degradation behaviour

Acknowledgement

This study was supported by the National Natural Science Foundation of China (51935014, 51905553, 81871494, 81871498, 51705540); Natural Science Foundation of Hunan Provincial (2019JJ50774, 2018JJ3671, 2019JJ50588, 2017JJ2392); JiangXi Provincial Natural Science Foundation of China (20192ACB20005); Guangdong Province Higher Vocational Colleges & Schools Pearl River Scholar Funded Scheme (2018); The Open Sharing Fund for the Large-scale Instruments and Equipments of Central South University; the Project of Hunan Provincial Science and Technology Plan (2017RS3008); Scientific Research Project of Hunan Provincial Health Commission (B20180054); Changsha Science and Technology Project (kq1706072).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes on contributors

Youwen Yang is a professor of Jiangxi University of Science and Technology.

Changfu lu is a postgraduate of Mechanical and Electrical Engineering, Jiangxi University of Science and Technology.

Shuping Peng is currently a professor of Central South University.

Lida Shen is a professor of Nanjing University of Aeronautics and Astronautics.

Di Wang is a professor of South China University of Technology.

Fangwei Qi is a professor of Jiangxi University of Science and Technology.

Cijun Shuai is a professor of Central South University.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (51935014, 51905553, 81871494, 81871498, 51705540); Natural Science Foundation of Hunan Provincial (2019JJ50774, 2018JJ3671, 2019JJ50588, 2017JJ2392); JiangXi Provincial Natural Science Foundation of China (20192ACB20005); Guangdong Province Higher Vocational Colleges & Schools Pearl River Scholar Funded Scheme (2018); the Open Sharing Fund for the Large-scale Instruments and Equipments of Central South University; the Project of Hunan Provincial Science and Technology Plan (2017RS3008); Scientific Research Project of Hunan Provincial Health Commission (B20180054); Changsha Science and Technology Project (kq1706072).