Evaluation of Alloying Effects on the Mechanical and Corrosion Properties of Magnesium and its Alloys for Biomedical Applications

Abstract Magnesium alloys and their derivatives are considered promising materials for the future of implantology. The study investigates the influence of alloying elements on the mechanical and corrosion properties of magnesium alloys for materials intended for biomedical engineering. The research focuses on defining key concepts such as biocompatibility, biodegradability, and the criteria that determine the suitability of magnesium and its alloys as biomaterials for implants. The results demonstrate that the properties of magnesium alloys can be significantly improved by selecting appropriate alloying elements. In our case, we focused on alloying elements such as aluminium, zinc, and rare earth elements. Five samples from each main group of magnesium alloys, AZ (aluminum–zinc) and AE (aluminum–rare earth element), underwent a series of mechanical tests, including Vickers hardness measurements, as well as electrochemical analysis, specifically potentiodynamic polarization and electrochemical impedance spectroscopy. The behaviour of magnesium and its alloys was analysed in the work and experimentally verified in the simulated environment of the human body. Among the tested materials, the AZ91 alloy exhibited the most favorable mechanical and corrosion properties, confirmed by mechanical, potentiodynamic, and electrochemical tests. AZ91 showed a relatively positive corrosion potential, low corrosion current density, and a low corrosion rate. The aluminum alloying element in the AZ91 contributes to achieving higher strength of the alloy. However, the high percentage of aluminum remains a problem with the AZ91 alloy, which, in the long term, damages the functioning of processes in the organism. The findings also revealed that the addition of rare earth elements in AE alloys reduces their hardness. Future investigations will concentrate on finding alloying elements capable of improving the mechanical integrity and corrosion resistance of magnesium alloys while ensuring biocompatibility.