Effects of Different Rare Earth Elements on the Degradation and Mechanical Properties of the ECAP Extruded Mg Alloys

Junxiu Chen; Jie Zhan; Sharafadeen Kunle Kolawole; Lili Tan; Ke Yang; Jianhua Wang; Xuping Su

doi:10.3390/ma15020627

Effects of Different Rare Earth Elements on the Degradation and Mechanical Properties of the ECAP Extruded Mg Alloys

Materials (Basel). 2022 Jan 14;15(2):627. doi: 10.3390/ma15020627.

Authors

Junxiu Chen^{1

2

3}, Jie Zhan^{1

2

3}, Sharafadeen Kunle Kolawole⁴, Lili Tan⁵, Ke Yang⁵, Jianhua Wang^{1

2

3}, Xuping Su^{1

2

3}

Affiliations

¹ Key Laboratory of Materials Surface Science and Technology of Jiangsu Province, Changzhou University, Changzhou 213164, China.
² Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Changzhou University, Changzhou 213164, China.
³ National Experimental Teaching Demonstration Center of Materials Science and Engineering, Changzhou University, Changzhou 213164, China.
⁴ Mechanical Engineering Department, School of Engineering and Technology, Federal Polytechnic, Offa P.M.B 420, Nigeria.
⁵ Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China.

Abstract

Effects of different rare earth elements on the degradation and mechanical properties of the ECAP (equal channel angular pressing) extruded Mg alloys were investigated in this work. Microstructural characterization, thermodynamic calculation, a tensile test, an electrochemical test, an immersion test, a hydrogen evolution test and a cytotoxicity test were carried out. The results showed that yttrium addition was beneficial to the improvement of the alloy's strength, and the ultimate tensile strength (UTS) and yield strength (YS) values of the ECAPed Mg-2Zn-0.5Y-0.5Zr alloy reached 315 MPa and 295 MPa, respectively. In addition, Nd was beneficial to the corrosion resistance, for which, the corrosion rate of the ECAPed Mg-2Zn-0.5Nd-0.5Zr alloy was observed to be 0.42 ± 0.04 mm/year in Hank's solution after 14 days of immersion. Gd was moderate in improving both the corrosion resistance and mechanical properties. Moreover, after co-culturing with murine calvarial preosteoblasts (MC3T3-E1) cells, the ECAPed Mg-2Zn-0.5RE (Nd, Gd, Y)-0.5Zr alloys exhibited good cytocompatibility with a grade 1 cytotoxicity. Consequently, the ECAPed Mg-2Zn-0.5Nd-0.5Zr alloy showed the best application prospect in the field of orthopedics.

Keywords: ECAP; Mg alloy; corrosion resistance; mechanical properties; rare earth elements.

Abstract

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