Effects of deformation twinning on the mechanical properties of biodegradable Zn-Mg alloys

Shiyang Liu; Damon Kent; Nghiem Doan; Matthew Dargusch; Gui Wang

doi:10.1016/j.bioactmat.2018.11.001

Effects of deformation twinning on the mechanical properties of biodegradable Zn-Mg alloys

Bioact Mater. 2018 Nov 23;4(1):8-16. doi: 10.1016/j.bioactmat.2018.11.001. eCollection 2019 Mar.

Authors

Shiyang Liu^{1

2}, Damon Kent^{1

3

4

2}, Nghiem Doan^{3

5}, Matthew Dargusch^{1

3

2}, Gui Wang^{1

3

2}

Affiliations

¹ School of Mechanical and Mining Engineering, The University of Queensland, St Lucia, 4072, Australia.
² ARC Research Hub for Advanced Manufacturing of Medical Devices, The University of Queensland, St Lucia, 4072, Australia.
³ Centre for Advanced Materials Processing and Manufacturing (AMPAM), The University of Queensland, St Lucia, 4072, Australia.
⁴ School of Science and Engineering, University of the Sunshine Coast, Maroochydore, DC, 4558, Australia.
⁵ School of Dentistry and Oral Health, Griffith University, Gold Coast, 4215, Australia.

Abstract

To satisfy the property requirements for biodegradable medical implants, Zn alloyed with low levels of Mg (≤0.8 wt%) has attracted increased research interest. In the present study, deformation twinning was observed in tensile tests and twinning appears to have an adverse impact on ductility. The profuse twinning in the as-cast Zn-Mg alloys accelerated crack growth in tension due to twinning impingement which caused local stress concentrations and initiates cracking. As-rolled Zn-Mg alloys have better ductility than their as-cast counterparts due to the inhibition of twinning by the refined Mg₂Zn₁₁ intermetallic phase and the finer grain size.

Keywords: Biodegradable metals; Deformation twinning; Hot rolling; Mechanical properties; Zn-Mg alloys.