Selective Laser Melted Rare Earth Magnesium Alloy with High Corrosion Resistance

Youwen Yang; Chenrong Ling; Mingli Yang; Liuyimei Yang; Dongsheng Wang; Shuping Peng; Cijun Shuai

doi:10.18063/ijb.v8i3.574

Selective Laser Melted Rare Earth Magnesium Alloy with High Corrosion Resistance

Int J Bioprint. 2022 May 31;8(3):574. doi: 10.18063/ijb.v8i3.574. eCollection 2022.

Authors

Youwen Yang^{1

2}, Chenrong Ling¹, Mingli Yang¹, Liuyimei Yang³, Dongsheng Wang², Shuping Peng^{4

5

6}, Cijun Shuai^{1

7}

Affiliations

¹ Institute of Additive Manufacturing, Jiangxi University of Science and Technology, Nanchang 330013, China.
² Key Laboratory of Construction Hydraulic Robots of Anhui Higher Education Institutes, Tongling University, Tongling 244061, China.
³ Ganjiang Innovation Academy, Chinese Academy of Sciences, Ganzhou 341119, China.
⁴ The Key Laboratory of Carcinogenesis and Cancer Invasion of the Chinese Ministry of Education, Central South University, Changsha, Hunan 410078, China.
⁵ NHC Key Laboratory of Carcinogenesis, School of Basic Medical Science, Central South University, Changsha 410013, China.
⁶ School of energy and machinery engineering, Jiangxi University of Science and Technology, Nanchang 330013, China.
⁷ State Key Laboratory of High Performance Complex Manufacturing, Central South University, Changsha 410083, China.

Abstract

Magnesium (Mg) degrades too fast in human body, which limits its orthopedic application. Single-phase Mg-based supersaturated solid solution is expected to possess high corrosion resistance. In this work, rare earth scandium (Sc) was used as alloying element to prepare Mg(Sc) solid solution powder by mechanical alloying (MA) and then shaped into implant using selective laser melting (SLM). MA utilizes powerful mechanical force to introduce numerous lattice defects, which promotes the dissolution of Sc in Mg matrix and forms supersaturated solid solution particles. Subsequently, SLM with fast heating and cooling rate maintains the original supersaturated solid solution structure. Immersion tests revealed that high Sc content significantly enhanced the corrosion resistance of Mg matrix because of the formation of protective corrosion product film, which was also proved by the electrochemical impedance spectroscopy measurements. Thereby, Mg(Sc) alloy showed a relatively low degradation rate of 0.61 mm/year. In addition, cell tests showed that the Mg(Sc) exhibited favorable biocompatibility and was suitable for medical application.

Keywords: Biocompatibility; Degradation behavior; Mg alloy; Rare earth; SLM.