Biodegradable WE43 Magnesium Alloy Produced by Selective Laser Melting: Mechanical Properties, Corrosion Behavior, and In-Vitro Cytotoxicity

Patrícia Lovašiová,Jan Suchý,Alena Michalcová,Tomáš Lovaši,Daniel Koutný,Enas Ghassan Hamed Alzubi,Dalibor Vojtěch,Jiří Kubásek,Eva Jablonská,Šárka Msallamová

doi:10.3390/met12030469

Abstract

In this work, selective laser melting (SLM) technology was used to prepare Mg-4Y-3Nd-Zr (WE43) alloy. This alloy and production method are promising for the design of biodegradable implants. The aim of this study was to investigate the chemical composition, microstructure, mechanical properties, corrosion behavior in simulated body fluid (SBF), and cytotoxicity of the alloy produced by SLM method and to compare it with conventionally gravity cast reference alloy. Analysis of the surface of the revealed an oxygen content of 7 wt.%. Undesirable unmelted and only partially adhered spherical particles of the starting powder were also found. The microstructure of the material was very fine and consisted of α-Mg dendritic matrix, β-Mg41(Nd, Y)5 intermetallic phase, Y2O3 inclusions, and 0.6 vol.% of residual porosity. The Vickers hardness, compressive yield strength, compressive strength, and maximum compressive strain were 88 HV0.1, 201 MPa, 394 MPa, and 14%, respectively, which are close to the reference values in as-cast. The in vitro corrosion rates determined by immersion and potentiodynamic tests were 2.6 mm/year and 1.3 mm/year, respectively. Cytotoxicity tests indicated good biocompatibility of the 3D-printed alloy.

Highlights

Magnesium and its alloys are interesting technical materials
The samples were cut into smaller pieces that were used for microstructural characterization, mechanical, corrosion, and biological testing
The aim of this work was to provide a comprehensive study of 3D-printed biodegradable alloy was used to prepare Mg-4Y-3Nd-Zr (WE43), including chemical, microstructural, mechanical, corrosion, and cytotoxicity tests

Summary

Introduction

Thanks to its excellent physical and chemical properties such as low density, high specific strength, good damping performance, it is widely used in the automotive and aerospace industries [1]. Magnesium is one of the most important elements in the human body, so it is non-toxic to the human body and degrades spontaneously in the body, and it can be used as a biodegradable material for implants, especially for bone fixation, so that reoperation after a fracture is not necessary. It can be used as a cardiovascular stent [2,6–9]

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